Eosinophilic infiltrate resembling eosinophilic cellulitis (Wells syndrome) in a patient with mycosis fungoides

Mycosis fungoides (MF) is a T-cell, non-Hodgkin lymphoma that primarily involves the skin. Extracutaneous involvement, such as in the parotid gland, is characteristic of end-stage disease. Eosinophilic cellulitis, or Wells syndrome, is a rare inflammatory dermatitis that involves a dermal infiltrate of eosinophils. We report a case of an 80-year-old man with a long-standing diagnosis of stage IIB MF who acutely developed parotid gland involvement and marked hypereosinophilia that most likely represented eosinophilic cellulitis. Activated T cells from his MF were likely a trigger factor for the development of his eosinophilic cellulitis. To our knowledge, this is the first reported case of an MF patient with atypical parotid gland involvement and eosinophilic cellulitis.