Search Results (54)

Cutaneous leiomyosarcoma is a rare, malignant tumor that arises from smooth muscle cells, accounting for less than 3% of all cutaneous sarcomas. Our case report details a 63-year-old male patient who presented with a rapidly growing, painful nodule in the popliteal region. The patient underwent initial surgical excision in September 2021, followed by three subsequent resections until March 2022 due to local recurrence. Histopathological analysis of all specimens revealed a dermal neoplasm composed of spindle cells arranged in intersecting fascicles with storiform patterns. The immunohistochemistry profile showed strong positivity for the markers SMA and desmin, confirming the diagnosis. Despite early interventions, the deep surgical margins were positive, and further surgeries were required until tumor-free margins were achieved. This case emphasizes the morphological characteristics, clinical behavior, and therapeutic challenges in managing cutaneous leiomyosarcoma. A favorable prognosis is achieved with long-term follow-up and a multidisciplinary approach. Full article

Background/Objectives: Angioimmunoblastic T-cell lymphoma (AITL) is a rare peripheral T-cell lymphoma of follicular helper T-cell (TFH) origin, often associated with immune dysregulation and EBV-positive B-cell proliferation. Kaposi sarcoma (KS) is a vascular neoplasm caused by human herpesvirus 8 (HHV-8), typically arising in immunocompromised individuals. The synchronous occurrence of AITL and KS in HIV-negative patients is exceptionally rare, with only three cases previously reported worldwide. Case Presentation: We describe an 81-year-old HIV-negative Korean woman presenting with progressive generalized edema and dyspnea. Imaging revealed multifocal lymphadenopathy. Excisional biopsy of the inguinal lymph node showed two distinct but adjacent neoplastic processes. The AITL component demonstrated a polymorphous infiltrate of atypical TFH cells expressing CD3, CD4, CD10, PD-1, and Bcl-6, with monoclonal TCR-γ rearrangement and TET2 and RHOA mutations. The KS component comprised spindle cells with slit-like vascular spaces, red blood cell extravasation, and immunoreactivity for HHV-8, CD31, CD34, and ERG. The findings were consistent with a collision tumor. Despite supportive care, the patient’s condition deteriorated, and she was discharged with palliative care. Discussion: The coexistence of AITL and KS in an HIV-negative setting raises important pathogenetic considerations. AITL is characterized by profound immune dysregulation, with depletion of normal T-cell subsets, abnormal B-cell activation, and cytokine milieu changes that may favor latent viral reactivation. This immunologic environment may permit HHV-8 reactivation, thereby facilitating the development of KS even in the absence of overt immunodeficiency due to HIV infection. Our findings support the hypothesis that AITL-related immune dysfunction may create a permissive niche for HHV-8-driven neoplasia. Conclusions: This is the first reported case in Asia and the fourth worldwide of a collision tumor comprising AITL and KS in an HIV-negative patI dient. The case suggests that AITL-associated immune dysregulation may facilitate HHV-8 reactivation and KS development even in the absence of HIV infection. Awareness of this association is critical for accurate diagnosis and optimal patient management. Full article

Background: Spinal solitary fibrous tumors (SFTs) are a rare oncological entity, almost anecdotal in the pediatric population. They have a high relapse rate and represent an ongoing oncological challenge. Methods: In this article, we conducted a systematic review starting from a case report to highlight the current state of the art in managing these tumors. Results: Spinal solitary fibrous tumors (SFTs) are rare, slow-growing neoplasms that can be either intra- or extramedullary. Only a limited number of studies focus on primary pediatric spinal cord localization. Five pediatric cases of spinal SFT have been documented in the literature. On MRI, they typically present as highly vascularized, contrast-enhancing masses. Histologically, they are composed of spindle-shaped cells within a collagenous stroma featuring staghorn-shaped blood vessels. More aggressive subtypes, such as dedifferentiated SFTs, resemble high-grade sarcomas. The NAB2–STAT6 fusion is a key marker, driving EGFR signaling, collagen production, and fibrosis. Additional diagnostic markers include CD34, CD99, and Bcl-2. Surgical resection remains the primary treatment. In metastatic cases, chemotherapy—mainly with anthracyclines, dacarbazine, or temozolomide—is employed, although no standardized pediatric protocols exist. Anti-angiogenic agents, including tyrosine kinase inhibitors, have shown promise. Radiotherapy is used postoperatively for local disease control, but its impact on survival is still under investigation. Conclusions: Surgery remains the cornerstone of treatment, significantly impacting the natural history of the disease and symptom control. While clinical trials exploring radiotherapy and chemotherapy are ongoing in adults, no specific treatment protocol has been established for pediatric patients. Full article

Background and Clinical Significance: Myxoid liposarcoma (MLS) is a malignant soft tissue tumor that often presents as a painless, slow-growing mass and is known for its atypical extrapulmonary metastatic pattern. Although sciatic nerve involvement is rare, when present, it usually causes neurologic symptoms. In this case, a large MLS silently expanded and completely encased the sciatic nerve without causing deficits, highlighting the importance of early imaging, multidisciplinary planning, and individualized surgical strategy in managing complex soft tissue sarcomas. Case Presentation: This case report describes a 67-year-old male with a 30 cm encapsulated myxoid liposarcoma of the posterior left thigh. The tumor had grown insidiously over one year and completely encased the sciatic nerve without causing pain, paresthesia, or motor impairment. Selective embolization was performed preoperatively to minimize blood loss. A posteromedial surgical approach allowed for en bloc resection with negative margins and preservation of sciatic nerve integrity. Histopathology confirmed a myxoid liposarcoma composed primarily of spindle-shaped tumor cells. The patient experienced no postoperative complications or neurologic deficits. At the two-year follow-up, he remains disease-free with full functional recovery. Conclusions: This case illustrates the potential for large, asymptomatic myxoid liposarcomas to encase critical neurovascular structures without infiltration. Preoperative embolization as part of a multidisciplinary plan was key to achieving safe resection and excellent functional outcomes. Full article

Background: CIC-rearranged sarcoma is a rare and aggressive type of undifferentiated round cell tumor characterized by CIC gene fusion, most commonly CIC::DUX4. This study presents a series of eleven cases, highlighting their clinicopathological features. Methods: Pathology records (2019 to 2024) were searched using “sarcoma with CIC”, identifying eleven cases, of which seven referred cases were initially misdiagnosed. Pathological and clinical analysis was conducted. Treatment was dictated upon multidisciplinary panel discussion based on tumor stage. Follow-up data (1–25 months) was available for all patients. Results: The cohort included six males and five females, with a median age of 43 years (range;14–53), with nine in soft tissue and two in bone. Tumor size ranged from 3.5 cm to 20.0 cm (mean: 9.8 cm). Most cases showed sheets of undifferentiated round- to oval-shaped cells. Two cases showed an Ewing-like pattern, and one case showed spindle cells in a fibrotic stroma transitioning to epithelioid cells. Necrosis was present in nine cases, and mitotic count ranged from 2 to 38/ 10HPFs (mean = 14.2). CD99 was positive in (10/11) cases and WT-1 in (6/9). NKX2.2, S100, and MDM2 were positive in rare cases. CIC::DUX4 fusion was detected in four cases. FISH for CIC gene rearrangement was positive in seven cases, two of them confirmed by methylation analysis. Metastasis at diagnosis was common (n = 8), primarily in the lungs, with later metastasis to the brain and bone. At time of final analysis, eight patients died within a median of 10 months (range: 1–19 months), while three were alive, two with stable disease (for a period of 6 and 25 months) and one with progression after 10 months. Significant correlation was seen between overall survival and the presence of metastasis at diagnosis (p value = 0.03). Conclusions: CIC-rearranged sarcomas are rare, high-grade tumors with predilection for soft tissue. Misdiagnosis is frequent, necessitating molecular confirmation. These tumors are treatment-resistant, often present with lung metastasis, and carry a poor prognosis, especially with initial metastasis. Full article

Background and Clinical Significance: Kaposi sarcoma (KS) is a rare angio-proliferative mesenchymal tumor that predominantly affects the skin and mucous membranes but may involve lymph nodes and visceral organs. Clinically, it manifests as red-purple-brown papules, nodules, or plaques, either painless or painful, often with disfiguring potential. The diagnosis is traditionally based on clinical and histopathological evaluation, although non-invasive imaging techniques are increasingly used to support diagnosis and treatment monitoring. We report a case of HHV-8-negative Kaposi sarcoma evaluated with multiple non-invasive imaging modalities to highlight their diagnostic utility. Case Presentation: An 83-year-old man presented with multiple painful, violaceous papulo-nodular lesions, some ulcerated, on the lateral aspect of his left foot. Dermoscopy revealed the characteristic rainbow pattern. Dynamic Optical Coherence Tomography (D-OCT) allowed real-time visualization of microvascular abnormalities, identifying large serpentine and branching vessels with clearly delineated capsules. Line-field Optical Coherence Tomography (LC-OCT) showed irregular dermal collagen, vascular lacunae, and the presence of spindle cells and slit-like vessels. Histological analysis confirmed the diagnosis of Kaposi sarcoma, revealing a proliferation of spindle-shaped endothelial cells forming angulated vascular spaces, with red blood cell extravasation and a mixed inflammatory infiltrate. Conclusions: Non-invasive imaging tools, including dermoscopy, D-OCT, and LC-OCT, have emerged as valuable adjuncts in the diagnosis and monitoring of KS. These techniques enable in vivo assessment of vascular architecture and tissue morphology, enhancing clinical decision-making while reducing the need for immediate biopsy. Dermoscopy reveals polychromatic vascular features, such as the rainbow pattern, while D-OCT and LC-OCT provide high-resolution insights into vascular proliferation, tissue heterogeneity, and cellular morphology. Dermoscopy, dynamic OCT, and LC-OCT represent promising non-invasive diagnostic tools for the assessment of Kaposi sarcoma. These technologies provide detailed morphological and vascular information, enabling earlier diagnosis and more personalized management. While histopathology remains the gold standard, non-invasive imaging offers a valuable complementary approach for diagnosis and follow-up, particularly in complex or atypical presentations. Ongoing research and technological refinement are essential to improve accessibility and clinical applicability. Full article

Background: There is an ongoing debate about the role of perioperative chemotherapy in retroperitoneal sarcoma (RPS). The aim of this study was to evaluate the effectiveness of perioperative chemotherapy in subtypes of RPS that are considered chemosensitive, including retroperitoneal angiosarcoma, undifferentiated pleomorphic sarcoma, myxoid liposarcoma, spindle cell sarcoma, and synovial sarcoma. Methods: This is a population-based retrospective cohort study. Patients with localized retroperitoneal sarcoma who underwent surgery were included from the US National Cancer Database (NCDB). After propensity score matching for the factors age, sex, grade, margin status, and tumor size, multivariable logistic and Cox regression analyses were used to identify factors associated with systemic therapy and their potential impact on the survival of patients with localized RPS. Results: We included 851 patients who underwent surgery between 2004 and 2020 (85% white, 41% female, and mean age 62 years). Of those, 227 patients (26.7%) received perioperative chemotherapy. In multivariable logistic regression, age ≤ 60 and tumor grading GIII/IV vs. GI/II were associated with a higher probability of receiving perioperative chemotherapy. After propensity score matching, we detected no difference in overall survival between patients who received chemotherapy and those who did not (HR 0.89, CI 0.55–1.43; and log-rank p = 0.92). Patient age ≤80 and tumor grading GI/II vs. GIII/IV were associated with improved overall survival. Conclusions: In this large analysis, the use of perioperative chemotherapy was not associated with improved survival in rare, chemosensitive subtypes of retroperitoneal sarcoma. However, selection bias must be considered when interpreting these findings. Full article

Background/Objectives: The fusion of the TFCP2 gene with either EWSR1 or FUS typically results in a spindle cell and/or epithelioid variant of rhabdomyosarcoma. This is an ultra-rare type of sarcoma, with most of our knowledge about these coming from case reports and small case series. Herein, we describe the clinical characteristics and treatment course of 10 patients with TFCP2 fusion sarcomas. Methods: We identified 10 patients in our hospital system with TFCP2 fusion sarcomas and 43 previously reported cases in the literature. We assessed primary tumor characteristics, treatment regimens, and survival rates among all cases. Results: We find that TFCP2 fusion sarcomas most commonly occur in young adults (median age: 33 years) and arise in craniofacial bones (7/10, 70%). Concomitant ALK alterations and ALK overexpression is nearly universal, and two of our patients were treated with ALK inhibitors; one patient had a near complete response before eventual progression, while the other patient had progressive disease after 2 months. For most, the prognosis was poor. The median overall survival in this cohort was 24.7 months (range: 5.9–29.7 months). Four patients were treated with upfront surgery, and all four developed recurrent disease. The median time to recurrence following upfront surgery was 2.1 months (range: 0.73–6.9 months). Five patients received systemic therapy, and the median progression-free survival from the start of treatment to progression was 1.6 months (range: 0.97–2.7). We also review the 53 total cases of TFCP2 fusion sarcomas in the literature, again highlighting the dismal outcomes in this disease. Conclusions:TFCP2 fusion sarcomas are proven to be aggressive and have poor prognosis. Additional work is needed to define the optimal treatment course for TFCP2 fusion sarcomas. Full article

Clear Cell Sarcoma (CCS) of soft tissue is a rare and highly malignant neoplasm primarily affecting young adults, often presenting in the deep soft tissues of the extremities. Despite morphological and immunophenotypic similarities to melanoma, CCS arises from connective tissues and is characterized by a distinct genetic hallmark: the EWSR1-ATF1 fusion resulting from t(12;22)(q13;q12) translocation. This genetic signature is absent in melanoma, making molecular diagnosis essential for accurate differentiation. Additionally, recent evidence highlights the utility of PRAME as an immunohistochemical marker to distinguish CCS from melanoma and other neoplasms. Clinically, CCS commonly involves tendons and aponeuroses, with metastatic potential leading to poor prognoses despite optimal local disease management. Histologically, CCS features lobular growth, spindle-to-epithelioid cells with clear cytoplasm, and low mitotic activity, often necessitating a multimodal diagnostic approach incorporating histopathology, immunohistochemistry, and molecular testing. Therapeutically, wide surgical excision remains the cornerstone for localized disease, with sentinel lymph node biopsy aiding in staging. Adjuvant radiotherapy is considered in select cases, while chemotherapy has limited efficacy in metastatic settings. Emerging treatments, including targeted therapies focusing on EWSR1-ATF1-driven pathways and immune checkpoint inhibitors, offer hope for improved outcomes. This review synthesizes current knowledge on CCS, emphasizing diagnostic challenges, the role of PRAME, and advancements in therapeutic strategies to enhance patient care. Full article

Infantile Fibrosarcoma is a malignant tumor of fibroblastic origin, typically found in early childhood, locally aggressive, and characterized by molecular alterations that activate tyrosine kinase signaling, primarily the ETV6::NTRK3 fusion. In recent years, a series of fusions different from the classic one have been described, including NTRK1, RAF1, and BRAF. In this paper, we present a case of IFS with a novel EVI5::BRAF fusion. We observed a spindle cell neoplasm growing in intertwined fascicles within a fibrous stroma, without the formation of an immature osteoid matrix. Weak and focal immunoreactivity for S100 was observed. SATB2 exhibited diffuse and intense staining, with focal expression of osteonectin and negativity for caldesmon, Smooth Muscle Actin, desmin, GFAP, SOX10, MelanA, panTRK, and HMB45. The Ki67 index was 7%, and the tumor harbored an EVI5::BRAF genetic fusion. To the best of our knowledge, the EVI5::BRAF fusion has not yet been described in BRAF fusions in IFS. Nevertheless, further studies are needed to define the prognostic features of these emerging BRAF sarcomas, along with new anti-BRAF therapeutic approaches. Full article

Introduction: Adolescent/young adult (AYA) patients with metastatic soft tissue sarcoma (STS) typically face a dismal prognosis. However, a subset of patients with incurable disease lives beyond two years. Due to the rarity of diagnoses and inherent heterogeneity within this population, a paucity of data exists regarding the experiences of AYAs with an indolent course (and how to best capture these experiences). With increasing biological insight and clinical experience, including the use of targeted or immune therapies, it is anticipated that more such patients will experience prolonged survival. Our pilot study aimed to describe the clinical characteristics and illness experiences of AYAs with incurable yet indolent metastatic STS who were living two years after their diagnoses. Our exploratory aim was to generate a conceptual framework that could subsequently be tested in a multi-center study with a larger cohort of patients. Materials and Methods: Patients with metastatic incurable STS, aged 15–39 years at diagnosis, and at least two years from diagnosis, were eligible. Patients were recruited over a two-year period at a quaternary children’s hospital with a comprehensive AYA oncology program. Participants completed a demographic form and PROMIS short form questionnaires for seven domains and answered an open-ended question. Responses to open-ended questions were coded independently by two authors and utilized to generate themes. Clinical variables were collected from medical records. Results: Five patients completed questionnaires. Mean age was 29.4 years (18.5–39.8 years) at diagnosis and 34 years (23.2–45.7 years) at study. Three patients were female; two were male; four were White; and one was Black/African American. Diagnoses included ASPSCR1::TFE3 alveolar soft part sarcoma; WWTR1::CAMTA1 epithelioid hemangioendothelioma; INI-1 deficient epithelioid sarcoma; EWSR1::NR4A3 extra-skeletal myxoid chondrosarcoma; and low-grade ARHGAP23::FER spindle cell malignancy, a novel fusion-driven sarcoma. Mean time since diagnosis was 4.5 years (2.6–6 years), and mean treatment duration was 4.2 years (1.5–6 years). On average, patients received 4.8 lines (range 2–8 lines) of antineoplastic therapy. All patients received at least one targeted therapy or immune checkpoint inhibitor. Patients reported increased fatigue and anxiety and decreased physical function compared to the standardized US reference population. Themes emerging from qualitative responses included managing physical symptoms, navigating feelings of guilt and inadequacy, self-reflection generating gratitude, and changing illness experiences over time. Conclusions: AYA patients living with incurable metastatic soft tissue sarcoma for more than two years were treated with multiple lines of antineoplastic therapy longitudinally. PROMIS data identified fatigue, anxiety, and decreased physical function within this population. Exploratory thematic analysis of qualitative responses generated concepts that could be further tested in an expanded cohort of patients. Full article

Background/Objectives: Low-grade myofibroblastic sarcoma is a rare malignant myofibroblastic tumor, first described by Gabbiani et al. in 1971. It predominantly affects adult males and is uncommon in children. The tumor can occur anywhere in the body, with a preference for the limbs and head and neck regions, including the oral cavity. Methods: A case report of a 22-year-old male patient with no systemic conditions who presented with a painless, red, firm swelling between teeth 34 and 35 was examined. Panoramic radiography was unremarkable. The lesion measured 19 × 8 mm. Histological analysis revealed a spindle cell proliferation with atypia. Immunohistochemical staining was positive for SMA and showed a low Ki-67 proliferative index, while negative for Desmin, CD34, and beta-catenin. The final diagnosis was low-grade myofibroblastic sarcoma. Results: After surgical excision, the lesion recurred within one month. The patient was referred to the Portuguese Institute of Oncology for further treatment. Conclusions: Low-grade myofibroblastic sarcoma is a rare tumor with a tendency for local recurrence and metastasis. Accurate diagnosis, which includes histological examination and immunohistochemistry, is essential to differentiate it from other benign and malignant lesions. This case highlights the importance of an incisional biopsy to confirm diagnosis prior to surgical excision, thereby reducing the risk of relapse and enabling appropriate treatment planning. Full article

Feline injection-site sarcomas (FISSs) are malignant skin tumors of mesenchymal origin arising at local post-vaccination (or injection) sites. In recent years, a fluorescence imaging technique based on probes targeting α_vβ₃ integrin has been effectively applied for the surgical complete resection of the tumor. In our study, we investigated the utility of a commercially available anti-α_v integrin polyclonal antibody for the histopathological evaluation of FISS’s surgical excision margins. We collected 10 formalin-fixed paraffin-embedded (FFPE) feline excisional biopsies with a histopathological diagnosis of FISS (7 fibrosarcomas and 3 pleomorphic sarcomas) and wide margin tissue, along with one subcutaneous injection-site granuloma and 6 osteosarcomas. Samples were processed for histology, and slides were stained for IHC with the anti-α_v integrin antibody. Immunostained slides were evaluated for the cellular localization and intensity of the staining in different neoplastic and non-neoplastic cell populations. Neoplastic and non-neoplastic spindle cells had cytoplasmic positivity in all fibrosarcomas. Inflammatory cells, including macrophages of the injection-site granuloma, were negative. Multinucleated giant cells in the pleomorphic sarcomas had an intense membranous positivity. Although the anti-α_v integrin antibody was ineffective for the histopathological evaluation of surgical excision margins, the membranous localization of α_v integrin in multinucleated giant cells of pleomorphic sarcomas suggests that it plays a role in the oncogenesis of this FISS variant. Full article

Background and Clinical Significance: Femoral neck fracture frequently occurs in the elderly population but may also present in patients diagnosed with primary cancer or bone metastases. A pathological, oligosymptomatic fracture associated with epithelioid haemangioendothelioma (EHE), a rare endothelial cell-derived sarcoma, is uncommon. Case Presentation: A 44-year-old patient underwent biopsy procedures three times (2010, 2012, 2013) for a focal lesion of the left ischium, none confirming its malignant nature. The last biopsy revealed a neoplastic tissue with features of discrete dysplasia. The lesion did not undergo medical follow-up for seven consecutive years. In August 2020, the patient presented with right lower limb pain. A CT scan, PET/CT scan, and biopsy confirmed EHE with spindle/sarcomatous features. In November 2020, chemotherapy (5xADIC) started (PET/CT confirmed a partial response). After its completion in July 2021, bone progression occurred and sirolimus-based therapy was started. After 3 months, a small liver metastasis was visualized on PET/CT, which did not result in the termination of treatment. In December 2021, pamidronate-based antiresorptive therapy was started. Liver metastasis remained stable in follow-up CT scans. Due to pelvic and spinal lesions, the patient was assisted by elbow crutches and underwent radiotherapy, remaining professionally active. The patient did not report any trauma, but in August 2023, a subsequent CT scan revealed a subcapital fracture of the left femoral neck in the fusion phase. Due to pelvic changes and the stable nature of the fracture, surgical treatment was abandoned. Conclusions: An oligosymptomatic femoral neck fracture, not requiring medical intervention is considered a rare complication of bone cancer. Full article

Undifferentiated pleomorphic sarcoma (UPS) is an aggressive soft tissue sarcoma with a poor prognosis. The patients are usually found to have metastasis when the primary tumor is diagnosed. Eccrine syringofibroadenoma (ESFA) is a rare cutaneous adnexal lesion of eccrine duct origin. There are five subtypes, one of which is reactive ESFA, known to occur in reaction to an inflammatory or neoplastic process. In this article, we report a case of the co-existence of both UPS and ESFA in a 70-year-old male patient, presenting with a painless, erythematous, irregular surface nodule with a peripherally extended brownish hyperkeratotic plaque on the right palm. The histologic findings revealed an ill-defined dermal tumor of atypical epithelioid and spindle-shaped cells with large pleomorphic hyperchromatic nuclei and abundant eosinophilic cytoplasm. Some of those cells were multinucleated giant cells in the stroma with vascular proliferation and mixed inflammatory cell infiltrate. The tumor cells, which were only positive for vimentin, supported the diagnosis of undifferentiated pleomorphic sarcoma (UPS). Meanwhile, the overlying epidermis demonstrated hyperkeratosis, papillated epidermal hyperplasia, and proliferation of anastomosing slender cords and strands of cuboid cells within loose fibrovascular stroma. These findings are the characteristics of eccrine syringofibroadenoma (ESFA). We describe here a patient in whom reactive ESFA occurred on and surrounded the UPS tumor. Full article