Mucinous syringometaplasia mimicked by a clear cell hidradenoma with mucinous change

An adnexal tumor with features of both clear cell hidradenoma and mucinous syringometaplasia is reported. The lesion occurred as a solitary, asymptomatic, slow growing nodule of 6-months duration on the anterior neck of a 55-year-old woman. Serous fluid could be expressed from a central skin opening. Histologically, there was a squamous-lined invagination with foci of mucin-laden cells. A ductal component with a variable admixture of mucinous cells merged with a nearby clear cell hidradenoma. Because clinicopathologic similarities exist between mucinous syringometaplasia and clear cell hidradenoma with mucinous change, thorough sectioning of mucinous syringometaplasia-like lesions is necessary to exclude an associated sweat gland neoplasm.