Epithelioid Cells Research Articles

TFE3-rearranged Head and Neck Neoplasms: Twenty-two Cases Spanning the Morphologic Continuum Between Alveolar Soft Part Sarcoma and PEComa and Highlighting Genotypic Diversity.

TFE3 rearrangements characterize histogenetically, topographically, and biologically diverse neoplasms. Besides being a universal defining feature in alveolar soft part sarcoma (ASPS) and clear cell stromal tumor of the lung, TFE3 fusions have been reported in subsets of renal cell carcinoma, perivascular epithelioid cell tumor (PEComa), epithelioid hemangioendothelioma and ossifying fibromyxoid tumors. TFE3-related neoplasms are rare in the head and neck and may pose diagnostic challenges. We herein describe 22 TFE3 fusion neoplasms affecting 11 males and 11 females aged 4 to 79 years (median, 25) and involving different head and neck sites: sinonasal cavities (n = 8), tongue (n = 4), oral cavity/oropharynx (n = 3), salivary glands (n = 2), orbit (n = 2), and soft tissue or unspecified sites (n = 3). Based on morphology and myomelanocytic immunophenotype, 10 tumors qualified as ASPS, 7 as PEComas (3 melanotic; all sinonasal), and 5 showed intermediate (indeterminate) histology overlapping with ASPS and PEComa. Immunohistochemistry for TFE3 was homogeneously strongly positive in all cases. Targeted RNA sequencing/FISH testing confirmed TFE3 fusions in 14 of 16 successfully tested cases (88%). ASPSCR1 was the most frequent fusion partner in ASPS (4 of 5 cases); one ASPS had a rare VCP::TFE3 fusion. The 6 successfully tested PEComas had known fusion partners as reported in renal cell carcinoma and PEComas (NONO, PRCC, SFPQ, and PSPC1). The indeterminate tumors harbored ASPSCR1::TFE3 (n = 2) and U2AF2::TFE3 (n = 1) fusions, respectively. This large series devoted to TFE3-positive head and neck tumors illustrates the recently proposed morphologic overlap in the spectrum of TFE3-associated mesenchymal neoplasms. While all PEComas were sinonasal, ASPS was never sinonasal and occurred in diverse head and neck sites with a predilection for the tongue. The indeterminate (PEComa-like) category is molecularly more akin to ASPS but shows different age, sex, and anatomic distribution compared with classic ASPS. We report VCP as a novel fusion partner in ASPS and PSPC1 as a novel TFE3 fusion partner in PEComa (detected in one PEComa). Future studies should shed light on the most appropriate terminological subtyping of these highly overlapping tumors.

Primary Epithelioid Angiosarcoma of the Penis: A Case Report With a Brief Review of the Literature

Abstract: Angiosarcoma of the penis is an exceptionally rare mesenchymal tumor, with only about 30 cases documented in the literature. Because of its rarity and the often nonspecific clinical presentation, histopathological examination plays a critical role in accurate diagnosis. Angiosarcoma of the penis typically arises in the corpus cavernosum but has also been reported in the glans and urethra, often presenting with metastases. This report details a case of epithelioid angiosarcoma of the penis in an 84-year-old man, who presented with a rapidly enlarging, violaceous nodule on the glans penis. Histopathology revealed atypical epithelioid endothelial cells with pleomorphism and mitotic activity, and immunohistochemical markers such as CD31, Erythroblast transformation-specific [ETS]-related gene, and cellular myelocytomatosis oncogene confirmed the malignant endothelial neoplasm. The differential diagnosis excluded conditions such as epithelioid hemangioendothelioma and Kaposi sarcoma. Because of the rarity, standardized treatment protocols are lacking; however, wide excision with tumor-free margins and the potential for targeted therapies based on gene amplification are considered important. The review highlights the diagnostic challenges, prognostic factors, and current therapeutic approaches, emphasizing the need for further research to develop standardized treatment protocols.

Spontaneous globe rupture from an intraocular melanotic schwannoma.

Melanotic schwannoma (MS) is a rare neoplasm composed of Schwann cells with melanosomes in various maturation stages. While MS is typically observed in spinal nerve roots or peripheral nerves, their involvement in intraocular structures is uncommon. Here, we present a case of spontaneous globe rupture as the presenting feature of intraocular extension of a MS. Enucleation was performed to remove the lesion. Confirmatory light microscopy and immunohistochemistry were used to properly diagnose and differentiate from conventional schwannoma and uveal malignant melanoma. The ocular tumor in our patient showed melanin pigmentation with positive melanocytic markers. The tumor revealed spindle and epithelioid cells proliferating in fascicles, which has previously been described for MS. No choroidal invasion, moderate nuclear pleomorphism, and a low mitotic rate were observed supporting a diagnosis of MS in our patient. With reports of MS with high recurrence and metastatic spread rates, there have been some suggestions that MS should be considered an aggressive malignancy. This case highlights a dramatic presentation of a rare ocular malignancy with some features of aggressiveness. Our case report endorses the importance of close monitoring for local recurrence or metastasis to prevent a poor outcome.

Giant Angiomyofibroblastoma With a Florid Lipomatous Component: A Report and Review of Diagnostic Considerations.

Angiomyofibroblastoma is a benign, usually small neoplasm typically constituted by spindle-shaped and epithelioid cells in a vascularized, myxoid-fibrous stromal background. It is most often seen in the superficial genitalia of female patients of reproductive age. However, various clinical and histologic features have been reported, including tumors in male patients, malignant transformation, extragenital sites, huge sizes, and a prominent lipomatous pattern. We report the clinical and pathologic features of one such tumor: a 23.5 cm lipomatous angiomyofibroblastoma of the vulva in a 40-year-old female patient. We also discuss important diagnostic considerations when approaching such large tumors, particularly in the setting of a biopsy specimen.

Gastric SMARCA4-Deficient Undifferentiated Carcinoma: A Report of 4 Patients and Literature Review.

SMARCA4-deficient undifferentiated carcinoma (SMARCA4-DUC) of the stomach is a rare gastric tumor that has been receiving increased attention in recent years. With its varied pathological presentations, accurate diagnosis can be challenging. In order to improve our understanding of this aggressive neoplasm, we have carefully documented and analyzed 4 patients with gastric SMARCA4-DUC, adding to the overall knowledge of this uncommon malignancy. The patients were all men, with an average age of 69 years (range 57-76 years). The tumors were located in the gastric antrum (2 patients), the gastric body (1 patient), and the cardia (1 patient). Microscopically, the 3 surgical specimens exhibited similar morphological features: large to medium sized tumor cells, round, irregular to epithelioid undifferentiated cells in solid sheets or discohesive nests, with no obvious stromal reaction. In one patient, short spindle cells arranged in reticular, pseudopapillary, and disorderly patterns were observed amidst extensive interstitial edema. Some areas displayed a lymphoma-like starry sky phenomenon. The biopsy specimens showed large cells diffusely distributed in the submucosa, presenting pale pink cytoplasm, fine chromatin, and prominent large red nucleoli resembling melanoma. All 4 patients demonstrated BRG1 (SMARCA4) loss, INI1 (SMARCB1) retention, and focal positivity for epithelial markers (AE1/AE3 or epithelial membrane antigen). Three patients had clinically advanced (stages IIIC-IV) disease. Follow-up revealed that 1 patient deceased within 4.8 months. This article expands the morphological spectrum of this cancer, providing new insights for accurate cancer diagnosis.

Sarcoid-like Reaction in a Patient With Colon Cancer: A Case Report and Mini-Review.

Sarcoidosis is a multisystemic and chronic inflammatory disorder characterized by the manifestation of epithelioid cell granulomas in various organs. Sarcoid-like reactions occur in patients who do not fulfill the diagnostic criteria for sarcoidosis but present with similar clinical and histological features. An 80-year-old man presented to our hospital with several subcutaneous nodules on the extremities. Based on clinical and pathological findings, the subcutaneous nodules were diagnosed as sarcoid nodules. However, the patient did not meet the diagnostic criteria for sarcoidosis. Positron emission tomography-computed tomography revealed abnormalities in several uptakes in the extremities that matched with the subcutaneous nodules and transverse colon. Additional examinations using lower gastrointestinal endoscopy, pathological examination, and contrast-enhanced computed tomography revealed tubular adenocarcinoma of the transverse colon. The patient underwent partial colon resection and lymph node dissection. The sarcoid nodules disappeared within 2 months postoperatively. Approximately 2 years later, there were no signs of recurrence of subcutaneous nodules, colon cancer, or additional findings suggestive of sarcoidosis. To our knowledge, this is the first report on a sarcoid-like reaction developing in the subcutaneous tissues of the extremities, associated with colon cancer, wherein the sarcoid nodules disappeared after the operation.

Ceus features of liver pecoma: a case report and literature review.

Perivascular epithelioid cell neoplasms (PEComas) and epithelioid angiomyolipomas (EAMLs) are two different denominations for the same "mesenchymal tumor composed of histologically and immunohistochemically distinctive perivascular epithelioid cells". Hepatic PEComa/EAML is a very rare neoplasm, and only 29 case reports of hepatic PEComa and 25 of hepatic EAML have been reported in the current literature. A clear female predominance with a mean age at diagnosis of 42.5years old can be observed by literature review. Ultrasound (US) examination was the first-line diagnostic technique in most of the cases of hepatic PEComa, but it was documented in very few cases of hepatic EAML. A great variability in the ultrasonographic B-mode, color Doppler and contrast-enhanced ultrasonography (CEUS) features of hepatic PEComa/EAML emerges. Computed tomography and magnetic resonance were the most common used techniques to confirm the nature of the hepatic lesion, even if the anatomo-pathological examination was the only technique to display a certainty diagnosis and to differentiate hepatic PEComa/EAML from benign and malignant hepatic lesions. The great majority of hepatic PEComas/EAMLs are surgically treated without any adjuvant therapy.

Clinico-histopathological characteristics and management outcome of rare chronic infective granulomatous diseases: A case series study

Granulomatous skin diseases are common cutaneous dermatoses commonly encountered by practicing dermatologist. Granulomatous skin lesions are distinctive pattern of chronic inflammatory response of skin due to reaction against various organic and inorganic antigens. Granulomas are characterized by focal collection of epithelioid cells or histiocytes, admixed with variable number of leucocytes (especially mononuclear cells) and multinucleated giant cells. Granulomatous reaction is a type IV hypersensitivity reaction evoked by poorly soluble reactive substances. Incidence and prevalence of different types of granulomatous dermatitis depend on geographic location. Granulomatous skin lesions are common in the eastern parts of India. Many granulomatous skin lesions have identical histomorphology and conversely a single pathology can produce varied histological features. Some rare suppurative chronic granulomatous skin diseases include Botryomycosis, Actinomycosis, Rhinosporoidosis, Nocardiosis, and Cutaneous Tuberculosis. To describe clinical, histopathological features and treatment outcome of rare chronic infective granulomatous diseases. In this observational case series study, we retrospectively analysed six biopsy proven cases of rare chronic infective granulomatous diseases presented to our department (OPD) of Dermatology, Venereology and Leprosy (DVL) over a period of six months between June 2023 to November 2023 at Great Eastern Medical School and Hospital (GEMS), Srikakulam, Andhra Pradesh, India. The patient’s full clinical history, morphology of lesions, histopathological findings and treatment outcome were analysed. Along with histopathology, other necessary laboratory investigations were performed if required. A total of six patients were involved in the study, of whom four were males and two were females. The male to female ratio was 2:1, with a slight male majority. The most common age group was 31-40 years for both males and females. Painful raised lesion for long duration was the predominant complaint among those patients. Out of these six rare chronic granulomatous diseases, bacterial infections were common than fungal infection. All the cases showed clinical improvement after one month of starting treatment.: Most of the patients had a chronic history with improper treatment. So, it is imperative that the clinical diagnosis has to be confirmed with histopathology for the definitive diagnosis and appropriate treatment of these rare chronic infective granulomatous diseases. All these rare cases showed excellent progress after starting the right treatment.

PATH-42. METASTATIC ADENOID CYSTIC CARCINOMA OF BREAST WITH BRAIN METASTASES AND LEPTOMENINGEAL DISEASE

Abstract INTRODUCTION Adenoid cystic carcinoma (ACC) of the breast rarely metastasizes to the brain and leptomeninges. ACC is a rare type of breast cancer, accounting for less than 0.1% of cases. It is usually triple negative, but has a good prognosis when it is confined to the breast. Lymph node involvement is uncommon, occurring in less than 2% of cases, and distant metastases to the brain are extremely rare. Leptomeningeal disease has not been reported yet. Case: In this case, we describe a 57-year-old woman diagnosed with triple-negative ACC of the right breast, which had spread to the axillary lymph nodes and distant metastases to the lung. The diagnosis was confirmed by biopsies of both metastatic sites. The patient received vinorelbine and cisplatin treatment for 11 cycles followed by right needle localized lumpectomy. While awaiting for the next steps in treatment she was admitted to the hospital for altered mental status, saddle anesthesia, and urinary incontinence. Neuraxis MRI revealed numerous hemorrhagic and non-hemorrhagic brain metastasis with diffuse leptomeningeal disease. Cerebrospinal fluid analysis confirmed leptomeningeal disease with positive cytology for atypical epithelioid malignant cells. The patient underwent whole brain radiation and focal radiation treatment to specific areas of leptomeningeal disease. Although she initially improved after the first month of radiation, her condition deteriorated rapidly, preventing the initiation of the next line of treatment with high-dose methotrexate or capecitabine. DISCUSSION Adenoid cystic carcinoma of the breast is exceedingly rare however with a very good overall prognosis. It is uncommon for ACC to spread to regional lymph nodes, and even rarer for distant metastasis. Brain metastasis is also infrequently reported. There are no documented cases of metastatic ACC with leptomeningeal disease, so there is no consensus on the best course of treatment.

Malignant Esophageal Glomus Tumor With CARMN::NOTCH2 Fusion: An Additional Tumor Underscoring the Frequent Tendency of Esophageal Glomus Tumors for Aggressive Behavior.

Malignant glomus tumors are rare tumors of pericytic origin with a propensity to develop in the upper gastrointestinal tract. Hereby we demonstrate a tumor of a 20-year-old man, who presented with dysphagia and an exophytic esophageal mass. Histologic examination of the resected mass revealed a multinodular tumor in the esophageal wall composed of epithelioid cells showing nesting and monomorphic atypia, staghorn vessels and scanty stroma. Immunohistochemically, the neoplastic cells were positive for SMA, and H-caldesmon, while desmin was negative. Collagen IV and laminin decorated a dense intercellular basal membrane meshwork. RNA-sequencing using TruSight RNA Pan-Cancer Panel revealed a CARMN::NOTCH2 fusion, that is a recurrent, frequently described and so far specific genetic alteration in glomus tumors. In spite of the adjuvant chemotherapy regimens, the patient died of disseminated metastatic disease 2 years after the diagnosis. Our patient presentation and the previous reports in the literature highlight the frequently aggressive behavior of glomus tumors arising in the esophagus.

Pediatric Mesenchymal Tumor With MN1::TAF3 Fusion.

MN1 fusion is emerging as oncogenic in soft-tissue tumors. Here, we provided detailed clinicopathological documentation of a tumor with MN1::TAF3 fusion. The tumor developed on the face of an 8-year-old boy and did not recur or metastasize for 5 years after surgery without adjuvant therapy. Histologically, the tumor predominantly comprised sheets and nests of atypical, mildly pleomorphic epithelioid cells. Mallory body-like eosinophilic cytoplasmic inclusions, small round cells, and fascicles of spindle cells were focally observed. Mitotic activity was high, and focal necrosis was present. Immunohistochemically, the tumor was positive for cytokeratin AE1/AE3 in the epithelioid cell component but otherwise showed nonspecific phenotypes. Targeted RNA sequencing identified an in-frame MN1 (exon 1)::TAF3 (exon 3) fusion transcript. We validated the transcript with reverse transcription-polymerase chain reaction, Sanger sequencing, and MN1 break-apart fluorescence insitu hybridization. MN1::TAF3 was previously listed without details in a large-scale sequencing study involving a pediatric round cell sarcoma in the orbit, raising the possibility that these tumors might form a coherent group.

Combined modalities for the rapid diagnosis of patients with suspected tuberculous lymphadenitis: A cross-sectional study.

In settings with high burden of extrapulmonary tuberculosis, the use of various diagnostic modalities can result in superior and quick diagnosis leading to prompt initiation of treatment. This study assessed the diagnostic performance of the fine-needle aspiration cytology (FNAC), Ziehl-Neelsen (ZN) stain, fluorescence microscopy (FM) and cartridge-based nucleic acid amplification test (CBNAAT) in patients with suspected tuberculous lymphadenitis (TBLN). This cross-sectional studyodes, who underwent FNAC. The FNAC samples were subjected to cytomorphological examinati involved 255 patients clinically suspected of TBLN with palpable lymph non, ZN stain, FM and CBNAAT. The diagnostic performance of each modality was compared with CBNAAT, and combined performance was determined. The diagnostic performance of CBNAAT was determined by comparing it with composite reference standard. Of 255 patients, 148 (58.04%) showed features of TBLN on FNAC. The presence of epithelioid cell granulomas with caseous necrosis (67.57%) was the predominant cytomorphological pattern. On ZN stain, FM and CBNAAT, 31 (20.95%), 63 (42.57%) and 100 (67.57%) patients were found to be positive for TBLN, respectively. The sensitivity, specificity, positive predictive value and negative predictive value of CBNAAT was 58.59%, 91.83%, 92% and 58.06%, respectively. Finally, the combination of ZN stain, FM and CBNAAT led to the detection of 88.51% patients with TBLN. Combined use of ZN stain, FM and CBNAAT leads to superior and swift diagnosis of patients with clinically suspected TBLN.

Gastrointestinal Tuberculosis: 8-year Experience from a Tertiary Care Hospital in North India.

Introduction: Tuberculosis (TB) represents a significant communicable disease on a global scale. The clinical manifestations of abdominal TB frequently resemble those of various gastrointestinal disorders, potentially leading to delays in accurate diagnosis. Materials and methods: From January 2012 to December 2019, consecutive patients aged 12 years and older, diagnosed with gastrointestinal TB at a tertiary care center in North India, were enrolled. Demographic and clinical data, radiological imaging findings, gastrointestinal endoscopy results, and histopathological findings were meticulously recorded. Antitubercular treatment was administered, and gastrointestinal endoscopy was performed upon the completion of treatment. Results: During the study period, 234 patients with gastrointestinal tuberculosis were enrolled, of which 151 (64.5%) were male and 83 (35.5%) were female. The most common presenting symptoms included weight loss (94.9%), abdominal pain (85.9%), fever (51.7%), and diarrhea (30.8%). The ileocecal region was the most frequently affected site (76.1%), followed by segmental colonic TB (17.1%). The most common finding on computed tomography (CT) of abdomen was thickening of the bowel wall with/without local or mesenteric lymphadenopathy. The most common endoscopic lesions were ulcerations (82.0%) followed by nodularity (73.9%), deformed cecum and ileocecal valve (41.9%) and strictures (11.1%). Histopathological examination of endoscopic biopsy revealed, well-formed granulomas in 94 (40.2%), collection of epithelioid cells with Langhans giant cells in 66 (28.2%), and chronic nonspecific inflammatory changes in 74 (31.6%). All patients responded to the antitubercular treatment. Follow-up colonoscopy in 171 (73.1%) patients showed regression of lesions. Conclusion: Gastrointestinal tuberculosis (GiTb) presents with nonspecific symptoms such as weight loss, fever, and abdominal pain, with ileocecal region being most commonly involved. Gastrointestinal endoscopy shows ulceration, nodularity, and strictures as prominent findings. Histopathology and culture were helpful for making diagnosis in almost half of the patients with GiTb. Majority of the patients responded well to antitubercular treatment.

Response to treatment with nab-Sirolimus in patients with perivascular epithelioid cell sarcoma of gynecologic or peritoneal origin: Subgroup analysis from AMPECT

Response to treatment with nab-Sirolimus in patients with perivascular epithelioid cell sarcoma of gynecologic or peritoneal origin: Subgroup analysis from AMPECT

Metastatic Mesothelioma of the Tunica Vaginalis Presenting as Scrotal and Abdominal Nodules: A Case Report and Review of the Literature.

Mesothelioma of the tunica vaginalis testis (MMTVT) is a rare neoplasm comprising <3% of all cases of malignant mesothelioma (MM). MMTVT derives from the tunica vaginalis testis, an outpouching of the mesothelial-lined abdominal peritoneum that detaches from the abdominal cavity after the descent of the testis. Similar to pleural mesothelioma, asbestos exposure is a known risk factor. However, MMTVT has a better prognosis than pleural mesothelioma. Cutaneous metastases from MMTVT are exceedingly rare. Herein, we describe a case of a 67-year-old man with a history of asbestos exposure presenting with scrotal pain and indurated plaques on his lower abdomen and scrotum. Histologic sections showed a sheet-like dermal proliferation comprising epithelioid cells with necrosis and increased mitotic activity. The clinical and histologic differential diagnosis was broad, including metastatic carcinoma, melanoma, sarcoma, germ cell tumor, hematologic malignancy, neuroendocrine carcinoma, and malignant mesothelioma. By immunohistochemistry, the neoplastic cells were positive for WT1, D2-40, and AE1/AE3, with rare positivity for calretinin, consistent with a diagnosis of mesothelioma. Additional immunohistochemical studies provided no support for the other diagnostic considerations listed above. BAP1 showed retained nuclear expression (normal) by immunohistochemistry. A DNA sequencing panel identified copy number losses in CDKN2A, MTAP, CDKN2B, and NF2, which are frequently identified genetic alterations in malignant mesothelioma. Subsequent testicular imaging demonstrated a diffusely thickened scrotal wall with an enlarged left testicle. Overall, this represents a case of malignant mesothelioma presenting with cutaneous metastases to the scrotum and lower abdomen, with clinical and imaging features suggestive of primary MMTVT. The International Mesothelioma Interest Group recommends using at least 2 mesothelial markers, such as calretinin, WT1, CK5/6 or D2-40, and 2 epithelial markers, such as claudin-4, CEA, MOC-31, as well as a broad-spectrum cytokeratin stain (AE1/AE3) as part of an initial immunohistochemical panel. Metastatic mesothelioma should be included in the differential diagnosis of malignant epithelioid dermal tumors with unusual staining patterns.

Perivascular epithelioid cell tumor of the uterus and pelvic cavity.

Primary perivascular epithelioid cell tumors (PEComas) of the female reproductive tract have been primarily reported as case reports owing to their clinical rarity. Limited incidence rates and clinical case data hinder a comprehensive understanding of the risks and invasiveness of this disease. We discuss herein the diagnosis, treatment, and prognosis of this disease to enhance comprehension and therapeutic strategies. We conducted a clinical analysis of patients with PEComa treated at the Gynecology Department of The West China Second University Hospital of Sichuan University between May 2018 and January 2024. Diagnosis and treatment were evaluated based on pertinent literature. Overall, eight patients (seven patients with tumors in the uterus and one patient with tumors in the pelvic cavity) were evaluated. One patient with PEComa of unknown malignant potential and two patients with malignant PEComa underwent hysterectomy and bilateral adnexectomy with or without adjuvant therapy and did not develop recurrence. Meanwhile, three patients who underwent lesion resection only exhibited radiological evidence of new lesions. Furthermore, postoperative imaging identified new pulmonary nodules in three patients. Although the current criteria are generally effective in assessing the tumor invasiveness of PEComa, emphasizing the significance of complete lesion resection remains crucial. Inadequate treatment significantly increases the risks of recurrence and metastasis. Additionally, the prevalence of pulmonary metastases may have been underestimated. Refining risk stratification to prevent overtreatment of low-grade malignancies or overlooking highly aggressive tumors is an important area for further study.

Deep Fungal Infections of Skin and Role of Histopathology in Diagnosis

Abstract Introduction: Deep mycoses acquired by penetrating trauma to the skin can have varied and sometimes atypical morphological presentations resulting in diagnostic dilemmas and delay in treatment onset. Histopathology can be a useful tool in not only diagnosing but also differentiating various deep mycoses. Aims and Objectives: To observe various morphological presentations and histopathological features of deep fungal infections. Materials and Methods: A retrospective multi-centric study was conducted from 2010 to 2020 at 16 centres. The cases with diagnoses of various deep mycoses were included in the study. The patients presenting with cutaneous manifestations were included in the study. Their demographic details, history, presenting signs and symptoms, morphological presentations, histopathological features and treatment details were collected from the case sheets. Results: A total of 124 cases were found from the case records. The most common type was chromoblastomycosis (42) followed by mycetoma (28) and rhinosporidiosis (17). The mean age was 43.76 ± 5.44 years. The average duration of symptoms before presentation was between 2 months to 10 years (average 2.5 ± 1.33 years). Male to female ratio was 1:0.7. Prior history of trauma was recorded in 36% of cases. Chromoblastomycosis cases presented with verrucous to atrophic plaques with black dots on the surface and histopathology findings included pesudoepitheliomatous hyperplasia, epithelioid cell granulomas, copper penny bodies within granulomas and abscesses. Rhinosporidiosis cases had polypoid grape-like lesions in the nose and eyes most commonly with histopathology findings of abundant thick-walled sporangia in dermis packed with thousands of spores. Eumycetoma patients had pigmented, indurated swelling with multiple sinuses discharging black granules and histopathology showed dermal abscesses and foreign body granulomatous reaction with PAS-positive hyphae. Histoplasmosis patients presented with few to multiple nodulo-pustular lesions on skin and palatal ulcers while small basophilic bodies packed in the cytoplasm of histiocytes were noted in histopathology. Phaeohyphomycosis cases presented as deep-seated cystic lesions and biopsy revealed deepithelialized cysts in the dermis or hypodermis with lumen showing necro inflammatory debris and fungal hyphae. Sporotrichosis cases had erythematous, tender nodules and papules either as single lesions or as multiple lesions arranged in a linear fashion and histopathology showed pseudoepitheliomatous hyperplasia of epidermis, loose to well-defined epithelioid cell granulomas and microabscesses. Spores were found in two cases. Cryptococcosis patient had multiple umbilicated lesions resembling giant molluscum contagiosum loose epithelioid cell granulomas and medium-sized spores lying in both intra and extracellularly on histopathology. Penicilliosis patients had nodulo-pustular lesions and histopathology showed an admixture of histiocytes, epithelioid cells, plasma cells, lymphocytes and polymorphs in the dermis with the presence of yeast-like spores in the cytoplasm of histiocytes and epithelioid cells. Entomophthoromycosis cases presented with asymptomatic subcutaneous firm swelling with loss of skin pinchability. Conclusion: Though clinical findings of deep fungal infections are characteristic similar morphology and atypical presentations can be sometimes confusing. Histopathology is useful for confirming the diagnosis.

Novel Driver Genes and Mutations in Lung Pecoma: A Case Report

Introduction: Perivascular epithelioid cell tumors (PEComa) are rare mesenchymal neoplasms characterized by perivascular epithelioid cells. Despite their common occurrence in the uterus, gastrointestinal tract, and retroperitoneum, this study presents an exceptional case of PEComa identified in the lung, warranting unique molecular exploration. Case Report: A 50-year-old man was diagnosed with a 6 cm neoplasm in the lower lobe of the right lung without enlarged lymph nodes during a routine examination. Thoracotomy, extended lower bilobectomy, and D3 lymphadenectomy were performed. Histological and immunohistochemical analysis diagnosed a PEComa. No conventional TSC1 and TSC2 mutations specific to PEComa, which resulted in mTOR pathway activation, were detected by whole-exome sequencing. In contrast, mutations were unveiled in the MTOR, EIF4EBP1, and PRAME genes that could be an alternative mechanism governing mTOR activation. Conclusion: These findings provide novel insights into the molecular intricacies of lung PEComa, showcasing the distinctive roles of MTOR, EIF4EBP1, and PRAME mutations.

Epithelioid solitary fibrous tumors from CNS and soft tissues: an unusual morphologic variant

BackgroundSolitary fibroous tumors (SFTs) are distinctive soft tissue tumors characterized by rearrangements of NAB2-STAT6 gene, which are associated with thin-walled, branching, “staghorn”-shaped vessels. SFTs are originally classified as a type of hemangiopericytoma (HPC). Classical SFTs are composed of spindle to ovoid cells arranged haphazardly or in fascicles. Rarely, SFTs exhibit unusual morphological variants such as fat formation, giant cells, dedifferentiation, or epithelioid variant. The epithelioid cell variant, which is composed almost entirely of epithelioid cells and arranged in solid or nest patterns, is extremely rare and frequently malignant.Case presentationIn this study, we reported three cases of epithelioid SFTs (ESFTs) located in extrathoracic sites (right lateral ventricle, right lumbar, left pelvis). All the subjects in this study were elderly, with a predominance of female patients, accounting for two out of the three cases, and only one case involved a male patient. The tumor cells were entirely composed of epithelioid cells and exhibited positive for CD34 and STAT-6 markers. Ultimately, the majority of cases (two out of three) were diagnosed as malignant SFTs.ConclusionThis study aims to enhance the awareness of ESFTs. In these cases, irrespective of the onset location, the arrangement patterns of tumor cells, such as papillary structures and the morphology of epithelial-like cells, conspicuously lack the hallmark histological characteristics of Solitary Fibrous Tumors (SFTs). Consequently, it requires differential diagnosis from a plethora of malignant neoplasms. Moreover, the elevated malignancy level of this cohort of cases poses substantial diagnostic challenges to pathologists, compounding the complexity of accurate interpretation.

Tuberculous Pleurisy in a Patient with a History of Breast Cancer: Diagnostic Challenges and Management Options

Background: Tuberculosis (TB) and cancer are increasingly prevalent diseases that can be challenging to diagnose due to similarities in clinical and radiological findings. This case report describes a 46-year-old woman with a history of breast cancer who developed tuberculous pleurisy (TP). Case presentation: A 46-year-old woman who underwent mastectomy and chemotherapy for BC in 2023 had hypertension, but no history of TB. The patient presented with dry cough, fever, and stomach discomfort, with an oxygen saturation level of 60%, but no respiratory distress before their appointment. Microscopy and culture tests were negative for Mycobacterium TB, A positive result was observed with an IFN-γ level of 0.35 IU/ml and 26% of the negative control after TB antigen stimulation. Histological analysis using hematoxylin and eosin staining showed Langhans giant cells, epithelioid cell granulomas, caseous necrosis, and necrotic foci. These findings indicate granulomatous inflammation with no signs of malignancy. Following the diagnosis, the patient received a daily dose of 300 mg isoniazid, 600 mg rifampin, 1500 mg pyrazinamide, and 10 mg pyridoxine for six months without any adverse effects. Conclusion: Physicians must employ a combination of diagnostic techniques, including morphological and microbiological confirmation, to accurately diagnose pleural effusion in this patient population.