Syringotropic Mycosis Fungoides
Syringotropic mycosis fungoides (MF) is clinically characterized by small papules superimposed on erythematous or brown patches or plaques of classic MF. It is quite rare and may accompany folliculotropic MF. The lesions are localized and often accompanied by hair loss, anhidrosis, and decreased sensation. There may be ulceration and scarring. Given the deep-seated location of the tumor infiltrate, topical therapies are less effective. Microscopically, syringotropic MF shows dense lymphoid infiltrates within and around sweat glands and ductal epithelium. Atypical lymphoid cells with irregular, hyperchromatic nuclei may be seen in the dermis. The ductal lumens are usually obliterated. The sweat gland epithelium may show reactive hyperplasia or be completely destroyed. Cytokeratin immunostain can highlight the remains of ductal epithelium.