Myoepithelial carcinoma (MEC) is a rare type of breast cancer composed purely of myoepithelial cells. Most often it presents with a spindle cell morphology that can mimic several benign and malignant lesions and may be misdiagnosed by the pathologist. We report 15 cases of MEC, which were sent to our consultation practice: Five of them were initially diagnosed as benign. The patients, all female, ranged from 45 to 86 years in age (mean 69.5) and-with one exception-presented with a breast mass. The tumor size measured between 1 and 4.8 cm (mean 2.6 cm). Microscopically, the tumors had infiltrative growth pattern most frequently with thin anastomosing cords of tumor cells associated with an intimately admixed reactive spindle cell stroma. The neoplastic myoepithelial cells were emanating from the myoepithelial cell layer of entrapped ductules in every case. The nuclei showed mild to moderate pleomorphism, and the mitotic activity ranged from 0 to 9/10 high power field. Immunohistochemical stains for p63, CD10, CK903, and CK5/6 reacted strongly and diffusely with the tumor cells, and mainly the reactive stroma had weak positivity for calponin, S-100, and smooth muscle actin. Estrogen receptor, progesteron receptor, and Her2 immunostains were negative, but strong epidermal growth factor receptor expression was observed. Follow-up was available for seven patients: All of them were alive at last contact; one patient had local recurrence, and one developed pulmonary metastases. MEC is a potentially aggressive malignant neoplasm sharing many features with metaplastic carcinomas. Morphologically, it is often difficult to distinguish it from benign spindle cell proliferations.
Anaplastic large cell lymphoma is a unique diagnostic subcategory of the T-cell lymphomas in the current World Health Organization classification. Representing approximately 3% of adult and 10% to 30% of childhood non-Hodgkin lymphomas, anaplastic large cell lymphoma classically consists of CD30+ large lymphoid cells with abundant cytoplasm and pleomorphic, often horseshoe-shaped or kidney-shaped nuclei. Among the reported nodal and extranodal sites of occurrence, the gastrointestinal tract and central nervous system have rarely been noted. We report a case of primary anaplastic lymphoma kinase–negative anaplastic large cell lymphoma in the brain of a 46-year-old patient with acquired immunodeficiency syndrome. T-cell lineage was confirmed by T-cell receptor γ chain gene rearrangements using polymerase chain reaction, and extra copies of the anaplastic lymphoma kinase gene of chromosome 2 were demonstrated by fluorescence in situ hybridization analysis. To our knowledge, primary anaplastic large cell lymphoma of the brain has not previously been reported in acquired immunodeficiency syndrome.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.