“Glowing Proof: ¹⁸ F FDG PET/CT Confirms Biopsy Accuracy”

Accurate tissue sampling is of prime importance in establishing a definitive diagnosis of any suspicious lesions, however conventional image-guided biopsies have some limitations and often yield an inconclusive results. We present a case of a 49-year-old female who presented with a palpable lump in the left chest wall. High-resolution computed tomography (HRCT) of the chest revealed a lytic lesion involving the right 8th rib with an associated soft tissue component, along with multiple nodules in the right lung. An initial computed tomography (CT)-guided biopsy was performed; however, it failed to provide a definitive histopathological diagnosis. The patient was subsequently scheduled for a positron emission tomography/computed tomography (PET/CT)-guided biopsy. A regional PET/CT scan using 2-deoxy-2-[ 18 F]fluoro-D-glucose ([ 18 F]FDG) was performed to identify the most metabolically active region of the lesion. Using robotic assistance, the biopsy trajectory was planned and a coaxial needle was precisely positioned within the most hypermetabolic portion of the rib lesion. Four to five core tissue samples were obtained, specifically targeting the areas of highest tracer uptake while avoiding necrotic or hypometabolic regions. To validate the adequacy of sampling, the extracted tissue cores were placed in a beaker with normal saline solution and it was scanned for 15 minutes using the PET/CT system. These extracted cores demonstrated intense focal [ 18 F]FDG uptake with minimal background activity, confirming that the samples corresponded to the metabolically active portion of the lesion. This intra-procedural validation provided an immediate confirmation of optimal tissue sampling prior to histopathological analysis. Subsequent histopathology established the diagnosis of a perivascular epithelioid cell tumor (PEComa). This case highlights the utility of PET/CT-guided biopsy and the additional value of scanning extracted cores to confirm adequate sampling, potentially improving diagnostic accuracy in metabolically heterogeneous tumors.