Trouble afoot: Mycosis fungoides bullosa at an unusual site

Excerpt

A 50 year old man had a diffuse skin eruption affecting the face, trunk, and upper extremities, with associated chronic pruritis. A skin punch biopsy of a forehead lesion was consistent with mycosis fungoides (MF) with folliculotropism, supported by clonal TCR gene rearrangement testing. Over the course of 3 years, the patient has received multiple lines of therapy including radiation, phototherapy, bexarotene, brentuximab, romidepsin, and electron beam radiation therapy. He now presents with clinically progressed disease, including numerous bullous lesions bilaterally involving the soles of the feet, and superimposed cellulitis (Fig. 1a). A punch biopsy was performed from the sole of the foot, and demonstrates bullae formation (Fig. 1b), with involvement by MF and large cell transformation (Fig. 1c-e). The vesicobullous variant is a rare subtype of MF, and the mechanism underlying blister formation is unknown [1]. The diagnosis is facilitated by a known history of MF with classic skin lesions, and the differential includes secondary involvement by a bullous dermatitis. The appearance of bullae in MF may portend a poor prognosis [2].

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