An atypical relapse of acute myeloid leukemia diagnosed by 18F-FDG PET/CT.

Extramedullary relapse of acute myeloid leukemia (AML) after stem-cell transplant is very rare and often remains a diagnostic challenge. Although the diagnostic value of PET/CT has not been evaluated thoroughly in leukemia, it might be useful for detecting these focal localizations. We presented a case of a 58-year-old man, with a prior history of localized bladder cancer and a secondary AML, referred to our hospital with important thoracic backaches. PET/CT revealed the presence of meningeal carcinomatosis at the thoracic level, as well as lymph nodes, and muscular and bone metastases. Immunophenotyping of the cerebrospinal fluid aspirate showed a relapse of AML.