Search Results (256)

Background/Objectives: Scoliosis in children leads to complex physical, psychosocial, and functional impairments, yet evidence from low-resource settings is limited. To evaluate health-related quality of life (HRQoL) in Ethiopian children with scoliosis using WHODAS 2.0 and EQ-5D-Y, and to identify clinical and demographic correlates of disability. Methods: A hospital-based cross-sectional study was conducted at CURE Children’s Hospital of Ethiopia (1 April 2024–31 March 2025). Ninety-seven children aged 6–15 years with confirmed scoliosis were assessed. WHODAS 2.0 (36-item) captured disability across six domains, while EQ-5D-Y measured physical, psychosocial, and pain-related HRQoL. Clinical severity indicators (Cobb angle, trunk rotation, thoracic morphometrics, anthropometrics) were recorded. Analyses in Python 3.12 included descriptive statistics, correlation, and multiple regression to examine associations between scoliosis severity and HRQoL outcomes. Results: Ninety-seven Ethiopian children diagnosed with scoliosis (mean age 11.4 years, mean Cobb angle 73.5°) were assessed; congenital scoliosis was most common (45.4%), followed by idiopathic (38.1%) and neuromuscular (16.5%). WHODAS 2.0 revealed substantial disability, particularly in mobility (46.4%) and social participation (62.8%), with life activities and participation as the strongest contributors. Greater deformity, younger age, and smaller body size were linked to worse outcomes, with neuromuscular and very severe thoracolumbar cases most affected. EQ-5D-Y showed marked HRQoL impairments across domains, with psychological distress (mean 2.24/3), pain, and self-care limitations emerging as key burdens. The mean EQ score was 8.89/15 (59.2%), indicating reduced quality of life. Regression analyses highlighted pain, psychological distress, and self-care limitations as the domains most strongly associated with poorer HRQoL, while greater Cobb angle and higher ATR degree were also correlated with reduced quality of life. Conclusions: Ethiopian children with scoliosis experience significant multidimensional impairments in HRQoL, with mobility, social participation, pain, and psychological distress as dominant burdens. WHODAS 2.0 and EQ-5D-Y proved complementary in capturing these impacts, supporting their use for early detection, clinical care, and public health planning in resource-limited settings. Full article

Background: CLTC-related neurodevelopmental disorder is a rare condition primarily characterized by global developmental delay (GDD) and intellectual disability (ID). To date, approximately 41 cases involving CLTC gene alterations have been reported. We present the first individual with a complete deletion of the CLTC gene. Methods: The proband is a male from a non-consanguineous family, presenting with congenital nystagmus, hypotonia, GDD, and autism spectrum disorder (ASD). Chromosomal microarray analysis and trio exome sequencing were performed. A systematic review of previously reported CLTC variant cases was conducted to delineate the phenotypic spectrum. Results: A de novo 363-kb heterozygous deletion at 17q23.1 spanning the entire CLTC gene was identified. The systematic review confirmed GDD/ID as core features and revealed various ocular abnormalities in a subset of cases. These findings indicate that the clinical phenotype extends beyond neurodevelopment, with multi-system involvement. Conclusions: The phenotypic heterogeneity of CLTC-related disorders underscores the need for comprehensive physical examination to identify extra-neurological manifestations. Accurate diagnosis relies on integrating detailed clinical phenotyping with comprehensive genomic testing. Early, precise diagnosis facilitates multidisciplinary management, informed genetic counseling, and the establishment of long-term surveillance protocols. Full article

Background: Microtia is a congenital anomaly of the external ear that is frequently associated with conductive or mixed hearing impairment and potential developmental consequences. Although genetic factors may contribute to some cases, social and economic conditions can influence access to diagnosis, hearing rehabilitation, and specialized care. This study examined clinical severity, hearing disability, and socioeconomic characteristics among patients with isolated and familial microtia evaluated in Ecuador. Methods: A cross-sectional study was conducted at a tertiary referral center in Quito, Ecuador. A total of 143 patients with microtia were included. Clinical variables included hearing impairment, hearing device use, microtia severity, associated risk factors, and family history. Sociodemographic variables included age, sex, residence, economic level, and healthcare access. Categorical variables were summarized as frequencies and percentages, and continuous variables as medians with interquartile ranges. Group comparisons were performed using the chi-square test and the Mann–Whitney test. Multivariable logistic regression was used to assess factors associated with hearing device use. Statistical significance was set at p < 0.05. Results: Hearing impairment was present in 41.78% of patients, with similar prevalence in isolated and familial cases. Hearing device use was reported by 19.86% of the sample. Familial microtia showed a significantly different distribution of right-ear severity, with higher frequencies of grade 1 and grade 4 anomalies, whereas isolated microtia was more commonly grade 3. Significant differences were also observed in sex distribution and economic level. Isolated cases were more frequent among males, whereas familial cases showed a higher proportion of females. Familial microtia was concentrated mainly in the low-middle economic stratum. In multivariable analysis, no factor was independently associated with hearing device use, and confidence intervals were wide, indicating limited precision. Conclusions: In this tertiary referral sample, microtia-related disability and access to care appeared to reflect the combined influence of clinical vulnerability, familial aggregation, and socioeconomic disadvantage. The low use of hearing devices despite frequent hearing impairment indicates an important gap between clinical need and rehabilitation. Equity-oriented strategies, including early hearing screening, timely referral, financial protection for assistive devices, and improved access to specialized care, may help reduce unmet needs among patients with microtia. Full article

Glycosphingolipids (GSLs) are glycoconjugates in which a short and heterogeneous saccharide chain is attached to a lipid moiety called ceramide. Based on their sugar backbone, mammalian GSLs are primarily grouped into the ganglio-, lacto-/neolacto-, and globo-series. Sialic acid—containing GSLs are known as gangliosides. Complex ganglio-series gangliosides are particularly abundant in the brain, whereas simple ganglio-series gangliosides, as well as those belonging to other series or neutral GSLs, are less abundant and typical of non-neural tissues. Congenital disorders in the biosynthesis of the lipid moiety of sphingolipids (SLs) result from defects in enzymes and proteins involved in ceramide biosynthesis and transport. Congenital disorders in the biosynthesis of the sugar chain of GSLs specifically affect ganglio-series ganglioside biosynthesis and are caused by pathogenic variants in GM3 synthase (ST3GAL5) or GM2/GD2/asialo-GM2 synthase (B4GALNT1). Defective variants of the sialyltransferase ST3GAL3 and the galactosyltransferase B4GALT5 have been reported and proposed to impair GSL biosynthesis. The occurrence of these syndromes has provided new insights into the physiological and pathological roles of GSLs. Most of these disorders are associated with completely inactive enzyme variants, leading to severe neurological syndromes. Only a few cases highlighted variants that retained partial activity, resulting in milder phenotypes, which included non-syndromic intellectual disability. It is therefore conceivable that many undiagnosed patients, with mild neurological symptoms, may carry variants retaining residual enzyme activity, insufficient to ensure normal levels of brain GSLs. The purpose of this article is to encourage clinicians to look for additional GLS hereditary disorders associated with a milder phenotype. We also hope to boost future investigations by highlighting the most critical issues emerging from recent literature on SL and GSL biosynthesis and their related defects. Full article

Cytomegalovirus (CMV) remains one of the most relevant congenital and early-life infections in pediatrics because of its high global seroprevalence, lifelong latency, and potential for reactivation or reinfection. Biologically, the virus poses a particular threat during pregnancy, when maternal primary infection carries a substantially higher risk of transplacental transmission than non-primary infection, with fetal and neonatal consequences that vary according to gestational timing and host vulnerability. In children, CMV infection is common in the first years of life and may contribute to a broad spectrum of outcomes, ranging from asymptomatic infection to severe multisystem disease, neurodevelopmental impairment, and sensorineural hearing loss. Clinically, the document highlights the importance of timely maternal diagnosis, differentiation between primary and recurrent infection, and integration of prenatal, neonatal, radiological, and audiological assessment. Attention is given to symptomatic and asymptomatic newborns, preterm infants, and infants exposed through breast milk. The availability of antiviral strategies in pregnancy and infancy strengthens the rationale for early identification and risk stratification. Universal newborn screening emerges as a potentially valuable approach to improve case detection, enable prompt follow-up, and reduce long-term disability. Overall, a multidisciplinary and early-intervention framework is essential to optimize prevention, diagnosis, treatment, and long-term outcomes in pediatric CMV infections. Full article

Background/Objectives: L-2-hydroxyglutaric aciduria (L2HGA) is a rare autosomal recessive neurometabolic disorder marked by developmental delay, intellectual disability, and progressive movement abnormalities. Variants in RYR1 can cause congenital myopathies, but data on the co-occurrence of variants in populations are limited. The aim of this study was to characterize the clinical and genetic basis of the neurometabolic and neuromuscular abnormalities and to investigate the potential interaction between the identified variants. Methods: Patients with complex, previously undiagnosed clinical presentations underwent neurological evaluation, including brain magnetic resonance imaging, electromyography, biochemical testing, and whole-exome sequencing (WES). Identified variants were analyzed in silico and confirmed by Sanger sequencing in the patient and her parents. Three cases were reviewed, and one of these patients exhibited developmental delay, hypotonia, intellectual disability, and progressive motor dysfunction. Biochemical tests revealed markedly elevated urinary 2-hydroxyglutaric acid levels, consistent with L2HGA. Results: WES identified a homozygous likely pathogenic variant in L2HGDH (c.589_590insGGC, p.Q197insG), confirming the molecular diagnosis of L2HGA. In addition, a heterozygous missense variant in RYR1 (c.7268T>A, p.M2423K), classified as a variant of uncertain significance, was detected and was inherited from her mildly affected father. The L2HGDH variant explains the neurometabolic phenotype of the patient, whereas the RYR1 variant remains of uncertain significance, and its clinical contribution cannot be clearly established. Conclusions: To our knowledge, this case illustrates the co-occurrence of a likely pathogenic L2HGDH variant and a heterozygous RYR1 variant of uncertain significance. The findings expand the mutational spectrum of L2HGA and underscore the value of comprehensive genomic testing in complex neurometabolic and neuromuscular disorders. Full article

Background: Vertebral column resection (VCR) has historically been recognized as the most efficacious corrective intervention for severe rigid spinal deformities. Nevertheless, advancements in preoperative optimization, staged corrective methodologies, osteotomies, and contemporary instrumentation have broadened the spectrum of therapeutic options available. The definitive role of VCR in the modern management of rigid congenital spinal deformities remains a topic of ongoing scholarly discourse. Methods: This study presents two illustrative cases of severe congenital spinal deformities that were addressed employing various surgical methodologies, alongside a comprehensive review of the current literature pertaining to VCR and less invasive alternatives, including halo-gravity traction (HGT), temporary internal distraction techniques, pedicle subtraction osteotomy (PSO), asymmetric pedicle subtraction osteotomy (APSO), and multi-rod constructs. Results: The cases elucidated herein underscore the necessity for treatment strategies to be tailored specifically to the characteristics of the deformity, its flexibility, the neurological risks involved, and the individual patient’s specific attributes. In one case, significant deformity correction achieved via preoperative HGT facilitated successful management through multilevel Ponte osteotomies and posterior spinal fusion, thereby obviating the need for VCR. In other patient suffering from severe rigid congenital kyphotic deformity with pronounced anterior column deficiencies, VCR was deemed essential to realize adequate correction and neural decompression. All patients exhibited substantial radiographic correction, enhancements in health-related quality-of-life metrics, diminished disability and pain, while maintaining correction without neurological complications or implant failure at the final follow-up evaluation. Conclusions: VCR continues to be a vital element within the surgical repertoire for the treatment of severe rigid spinal deformities; however, it should not be deemed obligatory in every instance. Diligent preoperative evaluation, staged correction methodologies, and less invasive osteotomy techniques may permit satisfactory correction while mitigating surgical morbidity in suitably selected patients. Treatment approaches should be customized, favoring the least invasive procedure capable of achieving safe and lasting correction whenever practicable. Full article

Background/Objectives: Autophagy is a highly conserved eukaryotic cellular process whose dysfunction results in human pathologies including cancer and neurodegenerative disease. First identified in yeast, ATG genes are central players in autophagy. Mutations in core autophagy genes ATG5 and ATG7 have been previously reported to cause rare genetic disorders with autosomal recessive inheritance. Methods: Here we report, for the first time, variants in human ATG9B gene as causative factors for a rare neurodevelopmental disease with autosomal recessive inheritance. Three distinct mutations were detected in three independent families with consanguinity, five patients affected in total. Results: The first variant is an 11-nucleotide deletion resulting in a frameshift. A premature stop codon is added and the C-terminal cytosolic domain of ATG9B protein is truncated. The second one is a point mutation that changes a critical amino acid in the transmembrane domain. The third variant is a 2-nucleotide deletion causing a different truncation product. Patients presented with diverse neurodevelopmental anomalies including intellectual disability, behavioral abnormalities, congenital cerebellar ataxia, mild cerebellar atrophy, and microcephaly. Since human ATG9B is expressed specifically in the placenta, we hypothesized that the disease pathology originates during placental development. To characterize the effects of the first frameshift mutation and gain insight into the specific functions of ATG9B in a physiological setting, we used mammalian cells and a knock-in mouse model. Truncated ATG9B was not stable when expressed in cells. It was localized to perinuclear vesicles like the WT protein, but not to peripheral vesicles. Homozygous knock-in mice were viable, fertile, and displayed no gross phenotypical abnormalities. Histomorphometry analysis of the placenta layers did not reveal a significant difference between mutant and control embryos. The assessments of neurobehavioral tests were similar in wild-type and homozygous knock-in mice. However, knock-in mice had a reduced fear memory trend, which is an amygdala-involved response. Conclusions: In this study, we describe a new rare disease linked to ATG9, including cerebellar ataxia and atrophy, as described for ATG5 and ATG7. Full article

49,XXXXY syndrome (Fraccaro syndrome) is a rare sex chromosome pentasomy, historically considered a severe variant within the Klinefelter spectrum. It is characterized by intellectual disability, craniofacial dysmorphism, skeletal anomalies, hypogonadism, and congenital cardiac defects. Although neuroimaging abnormalities have increasingly been recognized in 49,XXXXY syndrome, neonatal diagnosis prompted primarily by ventriculomegaly remains rare. We report a neonate with prenatally detected ventriculomegaly in whom postnatal evaluation revealed cleft palate, congenital cardiac defects, bilateral cryptorchidism, and auditory dysfunction. Cranial ultrasonography and brain magnetic resonance imaging demonstrated bilateral ventriculomegaly with colpocephaly and a cavum vergae variant. Cytogenetic analysis confirmed the presence of a 49,XXXXY karyotype. This case highlights ventriculomegaly as a potential early diagnostic clue in 49,XXXXY syndrome and underscores the importance of chromosomal analysis in neonates presenting with structural brain abnormalities associated with multisystem anomalies. Early recognition is important for timely multidisciplinary surveillance and long-term endocrine follow-up. Full article

Background: PPP1CB-related Noonan syndrome-like disorder with loose anagen hair type 2 (NSLH2; OMIM #617506) is a rare RASopathy caused by pathogenic variants in PPP1CB, encoding the catalytic beta subunit of protein phosphatase 1 (PP1C). Since its first description in 2016, only a limited number of patients have been reported, leaving the full phenotypic spectrum and genotype–phenotype correlations largely undefined. Objectives: To systematically review the clinical, molecular, and functional characteristics of NSLH2, we define its phenotypic spectrum, explore genotype–phenotype correlations, and summarize current evidence on therapeutic management. Methods: A systematic literature search was conducted across PubMed/MEDLINE, Embase, Web of Science, and Google Scholar, supplemented by searches of Orphanet, OMIM, and ClinVar, from 2016 to 2026. Studies reporting patients with pathogenic or likely pathogenic variants in PPP1CB were included. Individual patient-level data were extracted and analyzed descriptively. Additionally, we report a novel patient identified at our institution. Results: Thirty patients from 14 publications were included, harboring nine distinct PPP1CB variants. The most frequently identified variant was p.Pro49Arg (n = 17, 56.7%), followed by p.Met182Lys (n = 4, 13.3%) and p.Glu183Ala (n = 3, 10.0%). The majority of variants arose de novo (n = 26, 86.7%). Ectodermal anomalies, predominantly slow-growing and structurally abnormal hair consistent with loose anagen hair, were present in 79.3% of patients. Congenital heart defects were identified in 75.9%, with pulmonary stenosis and atrial septal defect representing the most common lesions. Short stature was documented in 69.2% of cases, and neurodevelopmental delay—encompassing motor and language delay—affected the majority of patients (72.4–84.6%). Brain structural anomalies were detected in 35.7%. Facial dysmorphic features were universal. Macrocephaly was present in 58.6% of cases, intellectual disability was reported in 26.9%, and epilepsy in 6.7%. Three familial cases with inherited p.Met182Lys transmission from an affected mother to three children are described, representing the largest reported familial cluster. Conclusions: NSLH2 is a clinically recognizable RASopathy with a consistent core phenotype comprising loose anagen hair, congenital heart defects, short stature, macrocephaly, and neurodevelopmental delay. The p.Pro49Arg variant accounts for the majority of reported cases and appears associated with a broad phenotypic expression. Larger cohorts and functional studies are needed to fully delineate genotype–phenotype correlations and guide therapeutic strategies. Full article

Disability is frequently theorized through a polarized medical-versus-social binary that can obscure the developmental, relational, and sociocultural processes through which bodily difference becomes psychologically meaningful. This study examines how adults with congenital or early-onset physical disabilities narrate and negotiate disability in everyday life, using psychoanalytic concepts as a complementary heuristic lens within an explicitly interdisciplinary framework that integrates developmental resilience and disability theory. Thirty-five in-depth life-story interviews were conducted with seven adults (25–40 years) across approximately five sessions per participant over two months. Data was analyzed using thematic qualitative content analysis, combining systematic coding of manifest content with interpretive attention to symbolic and relational meanings, while cross-checking psychoanalytic interpretations against developmental and social-disability perspectives. Four recurring compensatory patterns were identified: (1) symbolic resignification and verbal normalization (discursive reframing and minimizing disability); (2) achievement-oriented self-positioning (performance and perfectionistic striving); (3) compensatory role assumption (caregiving/protector roles and mastery enactments); and (4) silent family dynamics (familial denial and narrative). Within the specific context of this study, these patterns appeared to function as regulatory efforts to sustain self-cohesion, agency, and belonging. However, the narratives suggest that when these strategies manifest as rigid ideals of ‘overcoming’ and hyper-competence, they may carry a significant subjective cost for participants. Compensatory behaviors are best understood as ecologically embedded regulatory processes shaped by relational resources (experienced as containing/“holding”) and by sociocultural devaluation linked to ableist norms. An integrated model is proposed in which body, self, and environment co-constitute disability across development, clarifying when compensatory strategies support creative adaptation versus defensive rigidity. Full article

Background/Objectives: Early-onset epilepsy is associated with a high risk of developing drug-resistant epilepsy (DRE), often manifesting as developmental and epileptic encephalopathies (DEEs). This study aimed to characterize the incidence, syndromes, comorbidities, and etiology of early-onset DRE in Estonia. Methods: This study is a continuation of our earlier nationwide, population-based investigation and included all children with early-onset epilepsy (seizure onset before two years) who developed drug resistance in Estonia between 2013 and 2017 (n = 37). Cases were identified at the country’s only two pediatric neurology departments, ensuring nationwide coverage. Clinical data, electroencephalography, neuroimaging, genetic investigations (chromosomal microarray, single-gene tests, gene panels, exome/genome sequencing), and etiology were analyzed overall and by epilepsy type or syndrome. Results: A total of 37 children with early-onset DRE were included. The incidence of early-onset DRE was 26.5 per 100,000 person-years, peaking in the first year of life (36.1). Drug resistance developed in 43% within six months and 65% within one year. DEEs accounted for 76% of cases, most commonly infantile epileptic spasms syndrome (IESS/West syndrome, 35%). Structural abnormalities were observed in 49% of cases (50% of DEEs), most commonly congenital brain malformations (22%). Pathogenic genetic findings were identified in 41% overall (43% of DEEs). The etiology was established in 78% of children with DRE. Among DEEs, it was found in all Dravet syndrome patients (100%) and 62% of those with IESS/West syndrome. Global developmental delay/intellectual disability occurred in 86%, and motor impairment in 46%. Conclusions: Early-onset DRE, often presenting as DEE, has high incidence, progresses rapidly to drug resistance, and causes substantial comorbidities. Full article

Background: Achondroplasia, the most common genetic dwarfism caused by the FGFR3 mutation (autosomal dominant, 80% de novo), results in a disproportionately short stature. Thoracolumbar kyphosis (TLK), combined with characteristic spinal canal stenosis, increases the risk of symptomatic compression, yet the literature lacks clear thresholds for symptom onset or progressive deformity angles. Methods: A 16-year-old female with achondroplasia presented with rapidly progressive kyphosis despite conservative management (bracing and therapy). Over six months, she developed neurogenic claudication; bilateral leg pain; weakness; and paresthesia that worsened with standing/walking, which was relieved by flexion/sitting. Imaging demonstrated surgical-threshold kyphosis with progressive spinal misalignment. Her symptoms indicated compressive myeloradiculopathy from lumbar stenosis, critical given achondroplasia’s congenitally narrowed canal and heightened neurologic vulnerability. Results: Staged surgery planned: Posterior fusion T6-L4 with pedicle screws and then extensive decompression (laminectomy/foraminotomy T11-L3), L1 corpectomy with expandable titanium cage, and Ponte osteotomies. Intraoperative complications included a malpositioned left T10 screw breaching the anterior/lateral cortex near the aorta, requiring urgent revision. Postoperatively: Neurogenic bladder, wound leakage, and E. coli urinary tract infection (UTI) with fever (treated with IV antibiotics). After infection resolution, definitive surgery removed the malpositioned screw and completed decompression, corpectomy, cage placement, bone grafting, and osteotomies, successfully resolving neurological symptoms. However, 13 cm trunk lengthening caused severe functional impairment—disproportionately short arms prevented independent toileting and dressing. Left arm lengthening via external fixation restored partial function. At 2.5-year follow-up, there was solid fusion, no neurological deficits, and improved quality of life. Conclusions: Surgery addresses severe TLK, vertebral wedging, and neurogenic claudication in achondroplasia. Vertebral column resection effectively corrects TLK and neurological deficits but carries a high complication risk. This should be reserved for severe TLK with hypoplastic vertebrae, performed by experienced surgeons. Critically, correction magnitude must preserve limb–trunk proportions to prevent functional disability, as excessive lengthening may necessitate additional limb procedures for independence restoration. Full article

Background: Kleefstra syndrome (KS) is a rare neurodevelopmental disorder caused by haploinsufficiency of EHMT1; it is characterized by global developmental delay, intellectual disability, hypotonia, distinctive facial features, and variable congenital anomalies. Autistic features, behavioral abnormalities and severe speech impairment are frequently reported. However, molecularly confirmed cases of KS from Africa remain extremely limited, largely due to restricted access to genomic diagnostic infrastructures. Methods: We describe a 15-month-old patient from Rwanda presenting with neonatal hypotonia, global developmental delay, short stature, and characteristic dysmorphic facial features. Comprehensive clinical evaluation was performed, followed by trio-based exome sequencing to identify the underlying genetic cause of this neurodevelopmental disorder. Results: Exome sequencing identified a de novo heterozygous frameshift variant in EHMT1 (NM_024757.5: c.2871dup; p. Phe958Leufs*219), confirming the diagnosis of KS. Conclusions: This report presents the first molecularly confirmed case of KS in Rwanda. It highlights additional clinical features like bilateral 5th toe clinodactyly, short stature and absence of obesity in KS. There is a need to further delineate the study of EHMT1 and investigate the natural history of KS across different populations for optimal patient management and to reduce diagnostic odyssey. The diagnostic utility of exome sequencing for neurodevelopmental disorders needs to be strengthened, with strong emphasis on expanding genomic medicine to help diagnose rare diseases in resource-limited settings. Full article

Background and Clinical Significance: Urachal carcinoma (UrC) is an uncommon neoplasm derived from residual embryonic structures connecting the bladder to the umbilicus. Owing to its rarity, deep anatomic location, and histologic overlap with other glandular malignancies, accurate diagnosis remains challenging. Congenital anomalies of the lower urinary tract, including bladder exstrophy, are recognized as conditions that may predispose to malignant transformation of urachal remnants, although documented cases remain scarce. Case presentation: We describe the case of a 52-year-old male with bladder exstrophy and intellectual disability who presented with a progressively enlarging suprapubic mass and intermittent hematuria. Radiologic evaluation demonstrated a mass arising along the urachal tract. Surgical excision revealed a tumor composed of two morphologically distinct components: an enteric-type adenocarcinoma and a squamous carcinoma. Immunohistochemical profiling indicated urachal derivation and excluded other primary sites. Conclusions: This case expands the morphologic spectrum of UrC and emphasizes the diagnostic value of integrating clinical risk factors with detailed histologic and immunophenotypic assessment, particularly in tumors with mixed differentiation patterns. Full article