Sclerosing Microcystic Adenocarcinoma: Report of a Rare Case and Review of Literature

Abstract

Sclerosing microcystic adenocarcinoma is an exceedingly rare entity occurring in the mucosal surfaces of the head and neck that closely resembles cutaneous microcystic adnexal carcinoma. Here, we report a case of sclerosing microcystic adenocarcinoma that presented as a vague mass at the floor of the mouth in a 55-year-old woman. The pathology features and the diagnostic challenges, especially in the biopsy and margin evaluation are discussed here. Similar cases published in the English literatures are reviewed.

Sequencing of Sclerosing Microcystic Adenocarcinoma Identifies Mutational Burden and Somatic Variants Associated With Tumorigenesis

“…To our knowledge, this is the first study to profile SMA at the molecular level (1,6). Previous studies have attempted molecular characterization of MAC; SMA has often been described as a variant of MAC owing to its histological resemblance to sweat glands and infiltrative pattern and tendency toward perineural invasion but with a more favorable prognosis (1)(2)(3)8).…”

“…Several previous studies have observed SMA in the context of treatment with immunosuppression. One case report involved a patient treated with glatiramer for multiple sclerosis, while another involved a patient undergoing stem cell transplantation for AML (1,6). The patient in this case report previously received treatment with methotrexate, infliximab, adalimumab and apremilast.…”

“…SMA was first established as an entity distinct from MAC in a five-patient case series, including one case in the context of immunosuppression (acute myeloid leukemia or AML treatment) (1). A separate case of SMA was identified in the context of a patient diagnosed with multiple sclerosis previously treated with the immunosuppressive agent, glatiramer (6). Current SMA diagnosis relies heavily on histological evaluation and no studies have yet attempted the molecular characterization of this entity.…”

Microcystic Adenocarcinoma: An Initially Overlooked First Proposal of the Term

“…To the Editors, Our attention has been drawn to the recent report by Zhang et al [1], describing a single additional case of sclerosing microcystic adenocarcinoma, bringing to nine the number of examples documented in the English language literature [2][3][4][5]. Although the term "microcystic adenocarcinoma" was originally attributed to Mills et al [4] in 2016 [1,5], it is pertinent to make a few comments here on the first proposal of this entity in 2008 by Rosebush et al [6] that escaped the attention of the vast majority of pathologists.…”

“…Following a report by Johnston and Toker [7] in 1982, a number of definite or possible cases of salivary microcystic adenocarcinoma with sclerosing features were documented under a variety of names [1][2][3][4][5][6][8][9][10]. Without much supportive rationale, sclerosing microcystic adenocarcinoma is now only the designation that has survived this terminological conundrum [1,5]. Readers interested in the previously discarded terms are referred to two review articles [5,9].…”