Hyaline cell-rich chondroid syringoma: case report and review of the literature

SOX10-Internal Tandem Duplications and PLAG1 or HMGA2 Fusions Segregate Eccrine-Type and Apocrine-Type Cutaneous Mixed Tumors

Cutaneous mixed tumors exhibit a wide morphologic diversity and are currently classified into apocrine and eccrine types based on their morphologic differentiation. Some cases of apocrine-type cutaneous mixed tumors (ACMT), namely, hyaline cell-rich apocrine cutaneous mixed tumors (HCR-ACMT) show a prominent or exclusive plasmacytoid myoepithelial component. Although recurrent fusions of PLAG1 have been observed in ACMT, the oncogenic driver of eccrine-type cutaneous mixed tumors (ECMT) is still unknown. The aim of the study was to provide a comprehensive morphologic, immunohistochemical, and molecular characterization of these tumors. Forty-one cases were included in this study: 28 cases of ACMT/HCR-ACMT and 13 cases of ECMT. After morphologic and immunohistochemical characterization, all specimens were analyzed by RNA sequencing. By immunohistochemistry, all cases showed expression of SOX10, but only ACMT/HCR-ACMT showed expression of PLAG1 and HMGA2. RNA sequencing confirmed the presence of recurrent fusion of PLAG1 or HMGA2 in all cases of ACMT/HCR-ACMT, with a perfect correlation with PLAG1/HMGA2 immunohistochemical status, and revealed internal tandem duplications of SOX10 (SOX10-ITD) in all cases of ECMT. Although TRPS1::PLAG1 was the most frequent fusion, HMGA2::WIF1 and HMGA2::NFIB were detected in ACMT cases. Clustering analysis based on gene expression profiling of 110 tumors, including numerous histotypes, showed that ECMT formed a distinct group compared with all other tumors. ACMT, HCR-ACMT, and salivary gland pleomorphic adenoma clustered together, whereas myoepithelioma with fusions of EWSR1, FUS, PBX1, PBX3, POU5F1, and KLF17 formed another cluster. Follow-up showed no evidence of disease in 23 cases across all 3 tumor types. In conclusion, our study demonstrated for the first time SOX10-ITD in ECMT and HMGA2 fusions in ACMT and further refined the prevalence of PLAG1 fusions in ACMT. Clustering analyses revealed the transcriptomic distance between these different tumors, especially in the heterogenous group of myoepitheliomas.

Hyaline cell-rich chondroid syringoma: A potential pitfall on cytology

Chondroid syringoma is a rare adnexal tumor of skin, with few cases diagnosed on fine needle aspiration cytology (FNAC). Hyaline cell-rich chondroid syringoma (HCRCS) is a very uncommon variant of chondroid syringoma described in histopathologic studies. This variant differs from the usual chondroid syringoma in its site of presentation, cytohistologic features, and morphologically mimics malignant neoplasms. To the best of our knowledge, cytologic features of this entity have never been described. This case report highlights some unusual features of this tumor and discusses the cytologic features of HCRCS along with neoplastic mimics.

Cutaneous Myoepithelial Neoplasms on Acral Sites Show Distinctive and Reproducible Histopathologic and Immunohistochemical Features

Cutaneous myoepithelial neoplasms are a heterogenous group of neoplasms with mixed tumors typically affecting the head and myoepitheliomas showing a predilection for the extremities. Their malignant counterparts, myoepithelial carcinoma, and malignant mixed tumor are exceptionally rare in the skin, and the morphologic criteria for malignancy are only poorly defined. The aim of the present study was to characterize the clinicopathologic features of myoepithelial neoplasms presenting on acral skin. The clinical and histopathologic features of 11 tumors were recorded, and follow-up was obtained. Immunohistochemistry was performed for S100, SOX10, glial fibrillary acidic protein, keratins, epithelial membrane antigen, p63, p40, smooth muscle actin, desmin, and PLAG1. The tumors mainly affected the feet of adults (range: 26 to 78 y; median: 47 y) with a predilection for the great toe and a male predominance of 1.8:1. Most tumors (91%) displayed a lobular architecture composed of solid and nested growth of epithelioid cells with plasmacytoid features in a myxoid or angiomatous stroma. Scattered cytologic atypia and rare duct differentiation were frequently noted. Three tumors with confluent cytologic atypia, infiltrative growth, and lymphovascular invasion were classified as malignant. By immunohistochemistry, the tumors were positive for S100, SOX10, keratins AE1/AE3, CK5/6 and CK7, and PLAG1. Local recurrence and bilateral pulmonary metastasis were observed in a patient presenting with a histopathologically benign-appearing tumor. Two patients with malignant tumors experienced local recurrences, and 1 developed metastasis to soft tissue, lung, and mediastinal lymph nodes. All patients are currently alive, all but 1 with no evidence of disease after a median follow-up interval of 96 months (range: 2 to 360 mo). In conclusion, acral myoepithelial neoplasms show distinctive and reproducible histopathologic and immunohistochemical features. They are best regarded as a distinctive subset of mixed tumors with features reminiscent of their salivary gland counterparts. While most tumors pursue a benign disease course, histopathologic features appear to be a poor indicator of prognosis.

Hyaline Cell-Rich Apocrine Mixed Tumor with Cytologic Atypia

Hyaline cell-rich apocrine mixed tumor is relatively rare, and it often possesses atypical cells. Despite the presence of atypical cells, other histopathological features such as well circumscription, smooth border, predominance of bland cells, and no mitotic figures lead to classify these tumors as benign. In addition, no recurrence or metastasis has been reported even when cytologic atypia is identified. Here we report a case of hyaline cell-rich apocrine mixed tumor with cytologic atypia, which did not recur for 14 months after excision.

Benign mixed tumour of the breast and breast skin, two cases with diagnostic difficulties

We present two cases of pleomorphic adenoma, one that developed in the breast parenchyma and the other in the breast skin, with their histopathological differential diagnosis.

Hyaline cell-rich chondroid syringoma of the finger

A mixed tumor is a neoplasm that has microscopic features of both epithelial and mesenchymal differentiation. Such mixed tumors are known as pleomorphic adenomas in the salivary glands, and their cutaneous counterparts are called chondroid syringomas. These tumors commonly occur in the head and neck region of middle-aged men. Hyaline cell-rich chondroid syringoma is a rare benign variant of chondroid syringoma composed of cells with eosinophilic hyaline cytoplasm and plasmacytoid features, the origin of which remains elusive. Although very few cases have been reported in literature, it is important to be aware of this entity so as to avoid misdiagnosis on histopathological examination. In this report we present a case of hyaline cell-rich chondroid syringoma occurring in the finger.

Malignant melanoma in the 21st century, part 1: epidemiology, risk factors, screening, prevention, and diagnosis

Malignant melanoma is an aggressive, therapy-resistant malignancy of melanocytes. The incidence of melanoma has been steadily increasing worldwide, resulting in an increasing public health problem. Exposure to solar UV radiation, fair skin, dysplastic nevi syndrome, and a family history of melanoma are major risk factors for melanoma development. The interactions between genetic and environmental risk factors that promote melanomagenesis are currently the subject of ongoing research. Avoidance of UV radiation and surveillance of high-risk patients have the potential to reduce the population burden of melanoma. Biopsies of the primary tumor and sampling of draining lymph nodes are required for optimal diagnosis and staging. Several clinically relevant pathologic subtypes have been identified and need to be recognized. Therapy for early disease is predominantly surgical, with a minor benefit noted with the use of adjuvant therapy. Management of systemic melanoma is a challenge because of a paucity of active treatment modalities. In the first part of this 2-part review, we discuss epidemiology, risk factors, screening, prevention, and diagnosis of malignant melanoma. Part 2 (which will appear in the April 2007 issue) will review melanoma staging, prognosis, and treatment.

Early and tardive skin adverse events in chronic myeloid leukaemia patients treated with imatinib

Imatinib related non-haematological side-effects are reported in <10% of chronic myeloid leukaemia patients and include oedema, weight gain, nausea, vomiting and muscle cramps. Cutaneous reactions are well-recognized events occurring mostly in patients treated at doses of 600 mg/d and higher, either in stable or progressive disease. We report on our experience relating to dermatological toxicities in imatinib treated CML patients showing a spectrum of skin reactions ranging from rashes to cutaneous carcinoma.