bromochloroacetic-acid and Histiocytoma--Malignant-Fibrous

Myxoid spindle cell squamous cell carcinoma is a rare variant of squamous cell carcinoma that can pose diagnostic challenges because of its unusual morphology. In this article, we report the case of a 68-year-old man who presented with a slow-growing, fungating mass on the right tibia at the site of his long-standing draining sinus tract. Biopsy revealed a malignant spindle cell tumor with prominent myxoid stroma and areas containing thin-walled blood vessels with a curvilinear appearance. The immunohistochemical profile indicated that the neoplastic cells were positive for a variety of keratins (MNF116, Cam 5.2, AE1/AE3, 34βE12, and CK5/6) and transcriptional markers classically expressed in squamous cell carcinomas (p63 and p40). The tumor cells were negative for melanocytic and mesenchymal markers smooth muscle antibody, S100, caldesmon-h, desmin and CD34. Together, the clinical history, histologic appearance, and immunohistochemical panel was diagnostic of a myxoid spindle cell squamous cell carcinoma. The main differential diagnosis was myxofibrosarcoma. In addition to this clinical case, we also outline the current state of knowledge on this rare entity and discuss the importance of recognizing a Marjolin ulcer in this scenario.

Topics: Adult; Aged; Biomarkers, Tumor; Carcinoma, Squamous Cell; Fibrosarcoma; Histiocytoma, Malignant Fibrous; Humans; Immunohistochemistry; Keratins; Male; Osteomyelitis

ATF1, CREB1, and CREM, which encode the CREB family of transcription factors, are fused with EWSR1 or FUS in human neoplasms, such as angiomatoid fibrous histiocytoma. EWSR1/FUS-CREB fusions have recently been reported in a group of malignant epithelioid tumors with a predilection to the peritoneal cavity and frequent cytokeratin expression. Here, we studied 8 cytokeratin-positive abdominal malignancies with these fusions for further characterization. The tumors affected males (15 to 76 y old) and presented as intra-abdominal masses with concurrent or subsequent peritoneal dissemination, ascites, and/or metastases to the liver or lymph nodes. Four patients died of the disease within 18 to 140 months. Cases 1 to 5 showed multinodular growth of monomorphic epithelioid cells with focal serous cysts. Lymphoplasmacytic infiltration was prominent and was associated with systemic inflammatory symptoms. Two patients suffered from membranous nephropathy with nephrosis. The tumors displayed partly overlapping phenotypes with malignant mesothelioma, including diffuse strong expression of AE1/AE3 and WT1 and membranous positivity of sialylated HEG1, although calretinin was negative. Case 6 showed similar histology to cases 1 to 5, but expressed smooth muscle actin diffusely, lacked WT1 and HEG1, and harbored prominent pseudoangiomatous spaces. Cases 7 and 8 displayed dense growth of small oval to short spindle cells, with occasional molding and minor swirling, superficially resembling small cell carcinoma. Lymphoplasmacytic infiltration was not observed. The tumors were positive for AE1/AE3 and CD34 (focal), whereas calretinin, WT1, and HEG1 were negative. The detected fusions were FUS-CREM (n=4), EWSR1-ATF1 (n=2), EWSR1-CREB1 (n=1), and EWSR1-CREM (n=1). We confirmed the prior observation that these tumors do not fit perfectly with known entities and provided additional novel clinicopathologic information. The tumors require wider recognition because of more aggressive behavior than angiomatoid fibrous histiocytoma despite similar genetics, and potential misdiagnosis as unrelated diseases, such as neuroendocrine neoplasms.

Topics: Abdominal Neoplasms; Adolescent; Adult; Aged; Biomarkers, Tumor; Cyclic AMP Response Element Modulator; Gene Fusion; Genetic Predisposition to Disease; Histiocytoma, Malignant Fibrous; Humans; Immunohistochemistry; In Situ Hybridization, Fluorescence; Keratins; Male; Mesothelioma, Malignant; Middle Aged; Oncogene Proteins, Fusion; Phenotype; RNA-Binding Protein FUS; RNA-Seq; Treatment Outcome; Young Adult

Atypical fibroxanthoma (AFX) is an uncommon cutaneous neoplasm of pleomorphic myofibroblast-like cells. Diagnosis requires exclusion of other undifferentiated spindle and pleomorphic cell neoplasms by immunohistochemistry. We report two patients with p63-non-reactive spindle cell neoplasms which resembled AFX but demonstrated anomalous dot-like immunolabeling with antibodies to high molecular weight keratin and keratin 5. One case recurred locally, suggesting such lesions may behave aggressively. Whether these lesions represent keratin-positive dermal sarcomas or poorly differentiated carcinomas is debatable. Regardless of exact classification, our experience suggests such cases should be managed as high-risk non-melanoma skin cancers.

Topics: Aged; Carcinoma, Squamous Cell; Diagnosis, Differential; Histiocytoma, Malignant Fibrous; Humans; Immunohistochemistry; Keratins; Male; Membrane Proteins; Mohs Surgery; Neoplasm Recurrence, Local; Nevus, Spindle Cell; Skin Neoplasms; Xanthomatosis

Calretinin is an intracellular calcium-binding EF-hand protein of the calmodulin superfamily. It plays a role in diverse cellular functions, including message targeting and intracellular calcium signaling. It is expressed in the mesothelium, mast cells, some neural cells, and fat cells, among others. Because of its relative specificity for mesothelial neoplasms, calretinin is widely used as one of the primary immunohistochemical markers for malignant mesothelioma and in differentiating it from adenocarcinoma. On the basis of our sporadic observation on calretinin immunoreactivity in desmoid fibromatosis, we systematically evaluated calretinin, keratin cocktail (AE1/AE3), and WT1 immunoreactivity in 268 fibroblastic/myofibroblastic neoplasms. Calretinin was observed in 75% (44/58) of desmoid fibromatosis, 50% (21/42) of proliferative fasciitis, 23% (8/35) of nodular fasciitis, 33% (13/40) of benign fibrous histiocytoma, 35% (22/62) of malignant fibrous histiocytoma, and 13% (4/31) of solitary fibrous tumors but not in normal connective tissue fibroblasts at various sites. Keratin AE1/AE3 immunoreactivity was also commonly (6/13) present in the large ganglion-like cells of proliferative fasciitis and sometimes in nodular fasciitis (3/35), solitary fibrous tumor (3/27), and malignant fibrous histiocytoma (9/62). Nuclear immunoreactivity for WT1 or keratin 5 positivity was not detected in myofibroblastic tumors. On the basis of these observations, it can be concluded that calretinin and focal keratin immunoreactivity is fairly common in benign and malignant fibroblastic and myofibroblastic lesions. Calretinin-positive and keratin-positive spindle cells in desmoid and nodular fasciitis or calretinin-positive ganglion-like cells in proliferative fasciitis should not be confused with elements of epithelioid or sarcomatoid mesothelioma. These diagnostic pitfalls can be avoided with careful observation of morphology, quantitative differences in keratin expression, and use of additional immunohistochemical markers such keratin 5 and WT1 to verify true epithelial and mesothelial differentiation typical of mesothelioma.

Topics: Calbindin 2; Cell Nucleus; Diagnosis, Differential; Diagnostic Errors; Fasciitis; Fibromatosis, Aggressive; Histiocytoma, Benign Fibrous; Histiocytoma, Malignant Fibrous; Humans; Keratins; Myofibroma; S100 Calcium Binding Protein G; Solitary Fibrous Tumors; Tissue Array Analysis; WT1 Proteins

Although a few cases of sinonasal carcinoma with focal sarcomatous differentiation have been reported, pure sarcomatoid carcinoma has not been reported in the English literature. Imaging studies and gross inspection in a 60-year-old man with left-sided face pain revealed a mass in the left maxillary sinus and nasal cavity. A large incisional biopsy specimen from the nasal cavity revealed proliferation of malignant spindle and round cells with a malignant fibrous histiocytoma (MFH) pattern. Tumor giant cells were scattered, and there were areas of a vague storiform pattern. Mitotic figures were numerous. Carcinomatous component was not recognized. The histologic diagnosis was storiform-pleomorphic MFH. Tumor cells were positive for pancytokeratins AE1/3, KL-1, and CAM5.2 and cytokeratin (CK) 18, vimentin, CD68, p53, Ki-67 (labeling, 90%), α₁-antitrypsin, and α₁-antichymotrypsin and negative for pancytokeratin WSS, CK 34βE14, CK7, CK8, CK14, CK19, CK20, epithelial membrane antigen, S-100 protein, desmin, α-smooth muscle actin, CD34, HMB45, chromogranin, synaptophysin, myoglobin, CD45, CD30, and CD15. Because keratins were positive in tumor cells, a diagnosis of sarcomatoid carcinoma simulating MFH was made. The patient was treated with chemoradiation without significant effect and died 9 months after initial examination.

Topics: Biomarkers, Tumor; Carcinosarcoma; Combined Modality Therapy; Diagnosis, Differential; Fatal Outcome; Histiocytoma, Malignant Fibrous; Humans; Immunohistochemistry; Keratins; Male; Maxillary Sinus Neoplasms; Middle Aged; Nasal Cavity

Topics: Abdominal Neoplasms; Adolescent; Diagnosis, Differential; Fibroblasts; Groin; Histiocytoma, Malignant Fibrous; Humans; Keratins; Lymph Nodes; Lymphoma; Male; Melanoma; Vimentin

Topics: Antigens, CD; Antigens, Differentiation, Myelomonocytic; Carcinosarcoma; Esophageal Neoplasms; Esophagectomy; Histiocytoma, Malignant Fibrous; Humans; Keratins; Male; Middle Aged; Mucin-1; Vimentin