HIV-Infected Patient Diagnosed With Osteomedullary and Hepatic Syphilis on Positron Emission Tomography: A Case Report

A human immunodeficiency virus (HIV)-positive man presented with a recent history of weight loss and B symptoms. Positron emission tomography (PET) scan revealed multiple hypercaptation foci, including diffuse osteomedullary lesions and a dominant liver nodule. Syphilis screening was positive, with a rapid plasma reagin (RPR) titer of 1:1,024. Following antibiotic therapy, repeat PET scan demonstrated complete resolution of hypermetabolic lesions, arguing toward an infectious etiology. Cases of disseminated syphilis characterized on nuclear imaging typically demonstrate radiological evidence of target tissue inflammation. PET scan could however also represent a sensitive modality for evaluation of early subclinical secondary syphilis.