We report an
eccrine acrospiroma, on the cheek of a 29-year-old female, in which the presence of abundant mucinous (goblet cell)
metaplasia closely mimicked a primary
mucoepidermoid carcinoma. To determine the frequency of mucinous differentiation in benign adnexal sweat gland
tumors, we evaluated sixty-five cases in
hematoxylin and
eosin stained sections for the presence of goblet cells and sixty of these for
mucicarmine positivity. Goblet cell
metaplasia was seen in 3 of 12
acrospiromas, 1 of 8 mixed
tumors, and in 1 of 9 cases of
syringocystadenoma papilliferum. All goblet cells were positive for
mucicarmine, except in one case of
acrospiroma, where goblet cells were not detected on the section stained with
mucicarmine. In addition, intracellular
mucin, inclusive of goblet cells, was seen in 5 of 12
acrospiromas, 1 of 11
poromas, 5 of 8 mixed
tumors, 3 of 13
spiradenomas, 1 of 5
cylindromas, 3 of 9 cases of
syringocystadenoma papilliferum and 1 of 3 nipple
adenomas. The majority of the
tumors had both extracellular
mucicarmine positivity (40 of 60) and
luminal mucicarmine positivity (39 of 60). We conclude that mucinous differentiation in sweat gland
tumors, as defined by the presence of goblet cells and/or intracellular
mucicarmine positivity, is common and does not indicate aggressive behavior. Mucinous differentiation in benign sweat gland
tumors should not be confused with more aggressive
mucoepidermoid carcinomas of salivary gland origin or
adenosquamous carcinoma.