When ichthyosis occurs in adulthood, it may signify internal disease, especially malignant hemopathy. A 49-year-old man was admitted to hospital with diarrhea, fever, weight loss and abdominal pain. Physical examination showed generalized ichthyosis with palmoplantar hyperkeratosis and multiple inguinal lymph nodes. Laboratory investigations showed severe pancytopenia. Ultrasonography and CT scan demonstrated intraabdominal lymph node enlargement. Osteomedullary biopsy and open abdominal lymph node biopsy revealed an anaplastic large cell lymphoma. The lymph node involvement subsequently became worse and more severe, and the patient's general condition deteriorated. He died before receiving chemotherapy.