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

Disseminated cryptococcosis is extremely rare and is easily misdiagnosed as a malignant lymphoma. 18F-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.

A 21-years-old man presented with fever and cough for a month, with multiple red nodules scattered on the skin. 18F- 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.

Cryptococcosis was diagnosed using inguinal lymph node biopsy and blood culture.

The patient received two months of amphotericin B, fluconazole, and half a month of meropenem.

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.

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.