Regressing Papules on the Sole of the Foot: Answer

Abstract

Localized lymphomatoid papulosis, type C. DISCUSSIONOverall, the clinical and histologic findings in this patient were consistent with a diagnosis of localized lymphomatoid papulosis, histologic type C. Lymphomatoid papulosis (LyP) is the most common primary cutaneous CD30 + lymphoproliferative disorder and the second most common type of primary cutaneous T-cell lymphoma, following mycosis fungoides (MF). 1 Clinically, LyP is characterized by groups of papules or nodules at different cutaneous sites that completely regress and subsequently recur. 2 Lymphadenopathy is usually absent. Infrequently, these lesions may be localized to an isolated anatomic site (as in this case), a single lesion, or, very rarely, a solitary group of lesions on a background of MF. 3 In most cases, LyP follows an indolent, benign course with complete selfregression of the lesions.Histologically, LyP demonstrates considerable variability in morphology and degree of lymphoid atypia, frequently mimicking malignant lymphoma despite a benign clinical course. The World Health Organization-European Organization for Research and Treatment of Cancer classification recognizes 6 histologic subtypes of LyP, types A-E and a new subtype defined by chromosomal rearrangement 1,3,4 .