Reversible, PET-positive, generalized lymphadenopathy and splenomegaly during high-dose interferon-alpha-2b adjuvant therapy for melanoma.

A patient with resected stage III nodular melanoma treated with high-dose interferon-alpha-b2 adjuvant therapy went on to develop generalized lymphadenopathy and splenomegaly. The total body positron emission tomography showed a high F-fluorodeoxyglucose uptake (standardized uptake values >9), indicating possible lymph node and spleen malignancies. Histologic examinations of an axillary lymph node biopsy and an osteomedullar biopsy were negative, excluding both melanoma metastases and hematopoietic tumors. The symptoms completely regressed after suspension of treatment and a follow-up positron emission tomography was negative. It remains to be seen whether this unusual event can be ascribed to an autoimmune phenomenon linked to potential treatment efficacy and survival.