Lipomatous apocrine mixed tumor of the skin: an unusual giant lesion occurring in the breast

Clinical and pathological study on mixed tumors of the skin

Mixed tumor of the skin (MTS) is a rare benign tumor of the sweat glands with a reported frequency of 0.01% to 0.098%. The objective of the study is to investigate clinicopathological and immunohistochemical features of mixed tumor of the skin.This was a retrospective study of 21 patients diagnosed with MTS at the Institute of Dermatology and Venereology of Sichuan Provincial People's Hospital from 1980 to 2016. Pathological sections of all cases were reread and the diagnosis was verified.There were 14 males (67%) and 7 females (33%). MTS affected the face. The lesions were skin-colored or lightly red, with no subjective symptoms in most cases. Histopathologically, the tumors consisted of epithelial and interstitial components. The epithelium was mainly composed of cubic or polygonal cells, which can be seen within the tubule-like structures with bilayer epithelium. The inner cells mainly expressed cytokeratin and other epithelial markers. The outer cells expressed epithelial and mesenchymal markers. The outer cells expressed S-100, P63, and glial fibrillary acidic protein. The tumors showed interstitial mucus-like and fibrosis changes, and some parts had cartilage-like changes.Pathological diagnosis is particularly important because the clinical symptoms of MTS lack specificity.

Lipomatous pleomorphic adenoma in the hard palate: Report of a rare case with cyto-histo correlation and review

Pleomorphic adenoma is the most common benign tumor of the salivary glands. They are usually composed of epithelial/myoepithelial cells and chondromyxoid stroma. Extensive lipomatous differentiation is very rare. We report a case of lipomatous pleomorphic adenoma (LPA) that presented with a mass in the hard palate of a 32-year-old woman. The fine-needle aspiration cytology material was reported as benign cytology consistent with adenoma with major adipocytic component. Histopathological examination of the excision material displayed that more than 90% of the tumor was adipocytic in texture, containing scant epithelial and myoepithelial cells and chondromyxoid stromal fragments. Preoperative cytodiagnosis of lipomatous pleomorphic adenoma on FNA is based on cytomorphology intimately associated pleomorphic adenomatous and lipomatous tissue elements. LPA should be on the mental list of the (cyto)pathologist in differential diagnosis of lipomatous tumors or non-tumorous lipomatosis or carcinoma invasion in the adipose tissue of the minor salivary gland of the hard palate.