Syringometaplasia: variants and underlying mechanisms

Syringometaplasia is an adaptive, benign, metaplastic cellular process that affects the eccrine ducts and glands in response to a variety of physiological or pathological stimuli. Different subtypes of syringometaplasia have been described, including the squamous, mucinous, and adenomatous types. These metaplastic changes have been reported in association with chemotherapeutic agents, as well as with a variety of skin disorders including multiple infectious, neoplastic, and inflammatory skin diseases. In this review, we attempt to shed light on the different patterns of syringometaplasia, its pathogenesis, the plethora of skin conditions in which it may be observed, and the differential diagnoses that should be considered.