An Asymptomatic Case of Invisible Mycosis Fungoides

Mycosis fungoides has previously been reported in 'invisible' form, when biopsy of normal-appearing skin in the background of undifferentiated chronic pruritus demonstrated histopathologic findings of the malignancy. Asymptomatic cases have been reported more infrequently on biopsies of individual skin lesions. We present a case of invisible and asymptomatic mycosis fungoides, confirmed with immunohistochemical and T-cell receptor gene rearrangement studies, diagnosed on a re-excision specimen of an atypical melanocytic nevus. The case highlights the importance of alert examination of all tissue specimens for evidence of unrelated pathologic findings.