Disseminated cryptococcosis mimicking malignant lymphoma on (18)F-FDG PET/CT: A case report

Disseminated cryptococcosis is extremely rare and is easily misdiagnosed as a malignant lymphoma. (18)F-Fluorodeoxyglucose Positron Emission Tomography (PET)/ computed tomography (CT) may be useful to assess the involvement of disseminated cryptococcosis and to evaluate residual disease after treatment. PATIENT CONCERNS: A 21-years-old man presented with fever and cough for a month, with multiple red nodules scattered on the skin. (18)F- Fluorodeoxyglucose PET/CT revealed multiple hypermetabolic lymph nodes in the upper and lower parts of the diaphragmatic region and hypermetabolic nodules in the skin. According to the PET/CT results, malignant lymphoma was considered a possibility, especially T-cell lymphoma involving the skin. DIAGNOSIS: Cryptococcosis was diagnosed using inguinal lymph node biopsy and blood culture. INTERVENTIONS: The patient received two months of amphotericin B, fluconazole, and half a month of meropenem. OUTCOMES: The patient’s body temperature returned to normal and the red nodules on the skin disappeared. Most of the hypermetabolic enlarged lymph nodes disappeared, which was confirmed by reexamination with PET/CT. LESSONS: Disseminated cryptococcosis is easily misdiagnosed as malignant lymphoma, especially when the lymph nodes are more involved. When multiple hypermetabolic enlarged lymph nodes appear on PET/CT, except for lymphoma, specific infections should also be considered.