Myoepithelial carcinoma on the right shoulder: Case report with published work review

Abstract

Myoepithelial carcinoma is a malignant tumor that can differentiate towards myoepithelial cells and commonly occur in the salivary glands. There have been only a few reports of primary cutaneous myoepithelial carcinoma; however, most cases showed subcutaneous involvement and could also be diagnosed as soft tissue myoepithelial carcinoma arising from the subcutis with dermal involvement. It may thus be impossible to distinguish a primary cutaneous from a soft tissue myoepithelial carcinoma. Herein, we describe a case of myoepithelial carcinoma on the shoulder in an 85-year-old Japanese woman. The tumor was located in the whole dermis and subcutis; therefore, it could be diagnosed as either a cutaneous or soft tissue myoepithelial carcinoma. We reviewed previous cases of primary cutaneous and soft tissue myoepithelial carcinomas and compared their clinical and immunohistological features. We found no obvious differences in anatomical distribution or immunohistochemical findings. However, the recurrence rate of cutaneous myoepithelial carcinomas seems to be lower than that of soft tissue carcinomas. Such a difference may be attributable to the adequate surgical margin in cutaneous carcinomas compared with the deep-seated soft tissue carcinomas. The metastatic frequency did not significantly differ between the two types. Although we could summarize from only a small number of cases, these results indicate the difficulty in distinguishing between cutaneous and soft tissue myoepithelial carcinomas; furthermore, it may not be suitable to distinguish them on the basis of aggressive behavior.

Cutaneous syncytial myoepithelioma: A recently described neoplasm which may mimic nevoid melanoma and epithelioid sarcoma

“…Despite their designation as carcinoma, these cases have low metastatic potential. In a recently published review, the authors found that 2 cases of cutaneous myoepithelial carcinoma recurred and 2 had lymph node and distant metastasis out of 7 cases with available follow up (20). However, it is important to note that some of these cases may have represented soft tissue myoepithelioma with secondary cutaneous involvement, including the authors’ own case.…”

BRAF/MEK inhibitor-induced remission of primary cutaneous myoepithelial carcinoma after local recurrence

“… 1 Cutaneous MEC is an even rarer entity that has been most commonly reported on the head and neck and the lower extremities. 1 , 2 , 3 , 4 Reported cases suggest that MEC has a slight female predominance with a bimodal age distribution (before adulthood or after the fifth to sixth decades). 2 , 3 , 4 …”

“…Myoepithelial cells are ectoderm-derived, specialized basal epithelial cells located in the salivary glands, respiratory tract, breast, and sweat glands, although they can also express mesenchymal characteristics due to bidirectional differentiation. 2 , 4 Normal myoepithelial cells are spindle shaped and located around the eccrine and apocrine glands, where they assist with delivery of secretory products. 2 In tumor form, myoepithelial cells show several morphologies, including spindled, hyaline, epithelioid, and clear cell, and their proliferation can lead to either benign myoepitheliomas or malignant MEC.…”

“…Cutaneous myoepithelial carcinoma (MEC), also referred to as malignant myoepithelial tumor of the skin, is an extraordinarily rare diagnosis, with fewer than 15 cases reported in the scientific literature. 1 , 2 , 3 , 4 These tumors are aggressive, and surgical excision with clear margins is the treatment of choice. 2 , 3 However, postsurgical local recurrence and metastases occur in up to 30% and 15% of cases, respectively.…”

Metachronous Pancreatic and Thyroid Metastases from Primary Soft-Tissue Myoepithelioma in the Clavicular Region: A Case Report of a Long-Term Survivor

“…Although most cases of myoepithelioma are benign, some recur locally [9] or metastasize to other organs, such as the lung, liver, and brain [10]. However, metastasis to the pancreas and thyroid has not been reported.…”