A case of primary cutaneous anaplastic large cell lymphoma with prominent epidermotropism.

Primary cutaneous anaplastic large cell lymphoma (PCALCL) is defined as anaplastic large cell lymphoma localized to the skin without extracutaneous involvement at the time of diagnosis. Histologically, PCALCL is characterized by a dense nodular infiltrate of large lymphocytes, extending into the deep dermis or subcutis. Epidermotropism is sometimes, but not frequently, seen. We herein report a case of PCALCL with prominent epidermotropism. A 63-year-old Japanese woman was referred to our hospital with a red nodule and indurated erythema in 1997. Histological findings of a skin biopsy specimen from a red nodule were typical of PCALCL, however, biopsy specimens from indurated erythema showed remarkable epidermotropism. Tumor cells were positive for CD4, and CD30, but negative for CD3 and CD8. She was diagnosed with PCALCL. In 2007, skin biopsy was performed again, which showed large atypical lymphocytes in the upper dermis with mild epidermotropism. Tumor cells expressed in both CC chemokine receptor 4 and CXC chemokine receptor 3, which may explain prominent epidermotropism in this case.