Synchronous occurrence of primary cutaneous anaplastic large cell lymphoma and squamous cell carcinoma

CD30₊ lymphoproliferative disorders (LPD) represent a spectrum of T-cell lymphoma including lymphomatoid papulosis and anaplastic large cell lymphoma (ALCL). Epidermis overlying cutaneous CD30₊ LPD often shows epidermal hyperplasia, hyperkeratosis, crusting, and ulceration and it is difficult to distinguish from carcinoma such as keratoacanthoma (KA) or squamous cell carcinoma (SCC). Several cases of pseudocarcinomatous hyperplasia mimicking KA or SCC in CD30₊ LPD have been reported. The relationship between CD30₊ LPD and epithelial proliferations has not yet well understood. It was reported that a variety of mediators, including epidermal growth factor (EGF), transforming growth factor-α and EGFR from CD30₊ LPD could attribute to epidermal hyperplasia. However, separate and distinct SCC occurring in CD30₊ LPD has rarely been reported. Herein, we present a rare case of coexistence of SCC and cutaneous ALCL located on the same region.