Peripheral T-cell lymphoma in a patient with osteopetrosis.

Osteopetrosis is a rare genetic disorder in which the function of osteoclasts is defective, resulting in impaired bone resorption. This disease is usually accompanied by myelosuppression due to decreased marrow space and by osteomyelitis, especially in the submandibular bone. We report the case of a 72-year-old woman with an autosomal dominant form of osteopetrosis who suffered from peripheral T-cell lymphoma. Accurate clinical and pathological diagnoses and staging were difficult due to nonspecific reactive hyperplasia of the lymph nodes, even though we used several scintigraphic techniques and [18F]fluorodeoxyglucose positron emission tomography. We also paid special attention to myelosuppression and exacerbation of osteomyelitis after combination chemotherapy. Severe infectious complications were avoided by early administration of G-CSF for leukocytopenia and by continuous oral administration of antibiotics. The patient achieved complete remission after four courses of chemotherapy and this status has been maintained for 6 months.