Ki-1-positive anaplastic large cell lymphoma with different phenotypes in skin nodules and lymph nodes

A 54-year-old man had lymph node swelling and skin nodules. Neoplastic cells with pleomorphic nuclei, prominent eosinophilic nucleoli and abundant cytoplasm were present in the lymph node sinuses and around the dermal appendages. Neoplastic cells in the lymph nodes expressed Ber-H2 (CD30)+/KP1 (CD68)+/MAC387-/LN-5+. Those in the skin nodules expressed Ber-H2+/KP1-/MAC387+/LN-5-. These findings suggest that he had Ki-1-positive anaplastic large cell lymphoma (ALCL) with different phenotypes in lymph nodes and skin nodules. The discrepancy among KP1, MAC387 and LN-5 reactivities may represent the concurrent occurrence of ALCL and lymphomatoid papulosis. However, the possibility cannot be ruled out that ALCL developed first in the lymph nodes and then metastasized to the skin.