Search Results (11)

Myeloid/lymphoid neoplasms with tyrosine kinase gene fusions (MLN-TK) represent a distinct group of hematologic malignancies recognized in the latest WHO classification due to shared clinical, morphological, and molecular features, and their responsiveness to tyrosine kinase inhibitors (TKIs). Among these, fusions involving the SYK gene, such as ETV6::SYK and ITK::SYK, have emerged as rare but potentially targetable genetic events in both myeloid and lymphoid neoplasms. SYK, a non-receptor tyrosine kinase critical for hematopoietic signalling, can become constitutively activated through gene fusions, driving oncogenesis via the PI3K/AKT, MAPK, and JAK-STAT pathways. ETV6::SYK has been primarily associated with myeloid neoplasms, often presenting with eosinophilia, bone marrow dysplasia, and skin involvement. In vitro and in vivo models confirm its leukemogenic potential and identify SYK as a therapeutic target. Although SYK inhibitors like fostamatinib have shown transient efficacy, resistance mechanisms, possibly involving alternative pathway activation, remain a challenge. The ITK::SYK fusion, on the other hand, has been identified in peripheral T-cell lymphomas, particularly of the follicular helper T-cell subtype, with similar pathway activation and potential for targeted intervention. Additional rare SYK fusions, such as PML::SYK and CTLC::SYK, have been reported in myeloid neoplasms and juvenile xanthogranuloma, respectively, expanding the spectrum of SYK-driven diseases. Accumulating evidence supports the inclusion of SYK fusions in future classification systems and highlights the need for broader molecular screening and clinical evaluation of SYK-targeted therapies. Full article

Background: Adult xanthogranulomatous disease (AXD) is a rare histiocytic disorder with systemic potential, while xanthelasma palpebrarum (XP) is a common xanthoma often linked to lipid disorders. Differentiating these conditions is challenging due to overlapping features. Reflectance confocal microscopy (RCM), a non-invasive imaging tool, offers high-resolution visualization of skin structures and may aid diagnosis. Methods: We present a 71-year-old woman with periocular lesions. RCM was used to evaluate the lesions, identifying cellular and structural features. The findings were confirmed through histopathology, followed by surgical excision. Postoperative monitoring utilized RCM and LC-OCT. Results: RCM identified Touton giant cells, foamy histiocytes, and fibrosis, helping to distinguish xanthogranuloma from xanthelasma. Histopathology confirmed the diagnosis, and the patient underwent successful lesion excision without complications. Conclusions: This case underscores RCM’s utility as a diagnostic adjunct for differentiating AXD from XP in sensitive regions like the periocular area. The combined use of RCM and LC-OCT enhances monitoring for recurrence. While histopathology remains the diagnostic gold standard, RCM shows promise as a non-invasive tool, warranting further research to validate its role and develop standardized clinical protocols. Full article

This literature review aims to comprehensively evaluate the clinical and dermoscopic presentations of common pediatric diseases among children with skin of color (SoC) while also addressing potential variations based on racial backgrounds. This review encompasses various conditions, such as nevi subtypes, viral infections, infestations, and inflammatory dermatoses, as well as hair diseases and abnormal vascular formations, occurring in pediatric populations. Overall, we identified 7 studies on nevi subtypes, 24 studies on skin infections, 6 on inflammatory dermatoses, 10 on hair diseases and disorders, and 14 on miscellaneous disorders that also satisfied our SoC- and race-specific criteria. In case of no results, we assumed that dermoscopic findings are similar between SoC adults and children, confirming the hypothesis with our cases of dark-skinned Indian child patients. Inflammatory dermatoses such as psoriasis, eczema, and cutaneous mastocytosis, as well as skin infections like cutaneous leishmaniasis, appear with brownish backgrounds or exhibit dark structures more frequently than the respective dermoscopy images of Caucasian populations. Dermoscopy traits such as erythema in tinea capitis are uncommon or even absent on a dark-colored scalp, while a dark skin tone often obscures many characteristic features, such as dark and yellow dots in alopecia areata and even parts of an intradermal parasite in the case of scabies. Race-specific traits were also observed, such as corkscrew hair in tinea capitis, primarily seen in patients of African origin. Many dermoscopic images are consistent between SoC and non-SoC in various skin lesions, including vascular anomalies, juvenile xanthogranuloma, mastocytoma, and viral skin lesions like molluscum contagiosum, as well as in various hair disorders such as trichotillomania, while tinea capitis displays the most diverse reported dermoscopic features across SoC- and race-specific studies. Full article

Histiocytoses are rare diseases characterised by infiltration of affected organs by myeloid cells with a monocyte or dendritic cell phenotype. Symptoms can range from self-resolving localised forms to multisystemic lesions requiring specific treatment. To demonstrate extremely rare cases of CD68-negative cardiac histiocytosis with expression of SARS-CoV-2 antigen in infiltrate cells. We demonstrated a case of Erdheim–Chester disease in a 67-year-old man with pericardial involvement and positive dynamics with vemurafenib treatment, an autopsy case of xanthogranulomatous myopericarditis in a 63-year-old man, surgical material of xanthogranulomatous constrictive pericarditis in a 57-year-old man, and an autopsy case of xanthogranulomatosis in a 1-month-old girl. In all cases, xanthogranuloma cells expressed CD163, many of them spike protein SARS-CoV-2, while CD68 expression was detected only in single cells. In this article, we demonstrated four cases of extremely rare CD68-negative cardiac xanthogranulomatosis in three adults and one child with expression of the spike protein SARS-CoV-2 in M2 macrophages. This potential indirect association between COVID-19 and the development of histiocytosis in these patients warrants further investigation. To substantiate this hypothesis, more extensive research is needed. Full article

Congenital tumors are rare and, owing to this rarity, there is limited information on many of them. A total of 839 fetal and postnatal MRI studies performed in the first 3 months of life were retrospectively reviewed. They were performed with the use of 1.5 T scanners. Seventy-six tumors were diagnosed based on fetal MRI between 20 and 37 gestational weeks, and 27 were found after birth, from 1 day of age to 3 months of life. Teratomas were the most common tumors in our dataset, mainly in the sacrococcygeal region (SCT), followed by cardiac rhabdomyomas and subependymal giant cell astrocytomas (SEGA) associated with TSC, and neuroblastomas. The group of less common tumors consisted of infantile fibrosarcomas, malignant rhabdoid tumors, mesoblastic nephromas and Wilms tumor, craniopharyngiomas, brain stem gliomas, desmoplastic infantile astrocytoma, choroid plexus carcinoma, glioblastoma, hemangiopericytoma, rhabdomyosarcoma, melanoma, mesenchymal hamartomas of the chest wall and the liver, and juvenile xanthogranuloma, with special consideration of blue rubber bleb nevus syndrome. MRI plays a significant role in further and better characterization of congenital tumors, leading to a correct diagnosis in many cases, which is crucial for pregnancy and neonatal management and psychological preparation of the parents. No diagnosis is impossible and can be absolutely excluded. Full article

The identification of cancer predisposition syndromes (CPSs) plays a crucial role in understanding the etiology of pediatric cancers. CPSs are genetic mutations that increase the risk of developing cancer at an earlier age compared to the risk for the general population. This article aims to provide a comprehensive analysis of three unique cases involving pediatric patients with CPS who were diagnosed with multiple simultaneous or metachronous cancers. The first case involves a child with embryonal rhabdomyosarcoma, nephroblastoma, glioma, and subsequent medulloblastoma. Genetic analysis identified two pathogenic variants in the BRCA2 gene. The second case involves a child with alveolar rhabdomyosarcoma, juvenile xanthogranuloma, gliomas, and subsequent JMML/MDS/MPS. A pathogenic variant in the NF1 gene was identified. The third case involves a child with pleuropulmonary blastoma and pediatric cystic nephroma/nephroblastoma, in whom a pathogenic variant in the DICER1 gene was identified. Multiple simultaneous and metachronous cancers in pediatric patients with CPSs are a rare but significant phenomenon. Comprehensive analysis and genetic testing play significant roles in understanding the underlying mechanisms and guiding treatment strategies for these unique cases. Early detection and targeted interventions are important for improving outcomes in these individuals. Full article

Giant cells (GCs) are thought to originate from the fusion of monocytic lineage cells and arise amid multiple backgrounds. To compare GCs of different origins, we immunohistochemically characterised the GCs of reactive and neoplastic lesions (n = 47). We studied the expression of 15 molecules including HLA class II molecules those relevant to the cell cycle, bone metabolism and lineage affiliation. HLA-DR was detectable in the GCs of sarcoidosis, sarcoid-like lesions, tuberculosis, and foreign body granuloma. Cyclin D1 was expressed by the GCs of neoplastic lesions as well as the GCs of bony callus, fibroid epulis, and brown tumours. While cyclin E was detected in the GCs of all lesions, p16 and p21 showed a heterogeneous expression pattern. RANK was expressed by the GCs of all lesions except sarcoid-like lesions and xanthogranuloma. All GCs were RANK-L-negative, and the GCs of all lesions were osteoprotegerin-positive. Osteonectin was limited to the GCs of chondroblastoma. Osteopontin and TRAP were detected in the GCs of all lesions except xanthogranuloma. RUNX2 was heterogeneously expressed in the reactive and neoplastic cohort. The GCs of all lesions except foreign body granuloma expressed CD68, and all GCs were CD163- and langerin-negative. This profiling points to a functional diversity of GCs despite their similar morphology. Full article

Neurofibromatosis type 1 (NF1) is an autosomal dominant tumor predisposition syndrome that increases one’s risk for both benign and malignant tumors. NF1 affects every organ in the body, but the most distinctive symptoms that are often the most bothersome to patients are the cutaneous manifestations, which can be unsightly, cause pain or pruritus, and have limited therapeutic options. In an effort to increase awareness of lesser-known dermatologic associations and to promote multidisciplinary care, we conducted a narrative review to shed light on dermatologic associations of NF1 as well as emerging treatment options. Topics covered include cutaneous neurofibromas, plexiform neurofibromas, diffuse neurofibromas, distinct nodular lesions, malignant peripheral nerve sheath tumors, glomus tumors, juvenile xanthogranulomas, skin cancer, and cutaneous T-cell lymphoma. Full article

Xanthogranuloma of the sellar region is a rare chronic inflammatory lesion resulting from secondary hemorrhage, inflammation, infarction, and necrosis of an existing Rathke’s cleft cyst, craniopharyngioma, or pituitary adenoma. Sellar xanthogranulomas are challenging to differentiate from other cystic lesions preoperatively due to the lack of characteristic imaging features. We performed a literature overview of the clinical and paraclinical features, treatment options, and long-term outcomes of patients with sellar xanthogranuloma, focusing on the preoperative radiological diagnosis. The hyperintense signal in both T1- and T2-weighted sequences, cystic or partially cystic morphology, ovoid shape, sellar epicenter, intra- and suprasellar location, intratumoral calcifications, linear rim contrast enhancement, and the absence of cavernous sinus invasion suggest xanthogranuloma in the preoperative differential diagnosis. An endoscopic endonasal gross total resection without radiotherapy is the preferred first-line treatment. Given the low rate of recurrence rate and low chance of endocrinological recovery, a mass reduction with decompression of the optic apparatus may represent an appropriate surgical goal. Identifying the xanthogranulomas’ mutational profile could complement histopathological diagnosis and give insight into their histo-pathogenesis. A better preoperative neuroimagistic diagnosis of sellar xanthogranulomas and differentiation from lesions with a poorer prognosis, such as craniopharyngioma, would result in an optimal personalized surgical approach. Full article

Multiple papulonodular skin lesions at birth can indicate the presence of various benign and malignant disorders. Although the lesions’ clinical aspect (color and consistency, in particular) may steer the clinician towards one disorder or another (infantile myofibromatosis, xanthogranuloma, or metastatic neuroblastoma), the diagnosis can only be confirmed by the histopathologic assessment of a biopsy. In neonates, a rapid but accurate diagnosis is critical because skin lesions may be the first manifestation of a malignant disorder like leukemia cutis or metastatic neuroblastoma. Here, we review the various disorders that may manifest themselves as multiple skin lesions at birth. Full article

Neurofibromatosis type 1 (NF1) is a complex autosomal dominant disorder associated with germline mutations in the NF1 tumor suppressor gene. NF1 belongs to a class of congenital anomaly syndromes called RASopathies, a group of rare genetic conditions caused by mutations in the Ras/mitogen-activated protein kinase pathway. Generally, NF1 patients present with dermatologic manifestations. In this review the main features of café-au-lait macules, freckling, neurofibromas, juvenile xanthogranuloma, nevus anemicus and other cutaneous findings will be discussed. Full article