Metabolically Silent Diffuse Hepatic Involvement in Multiple Myeloma: An ¹⁸F-FDG-PET/CT Pitfall

Area of Science:

• Oncology
• Medical Imaging
• Hematology

Background:

• Diffuse hepatic involvement in multiple myeloma is an uncommon presentation.
• It can pose diagnostic challenges, particularly with advanced imaging techniques.
• Early and accurate diagnosis is crucial for effective management.

Purpose of the Study:

• To report a rare case of diffuse hepatic involvement in multiple myeloma.
• To illustrate the limitations of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in diagnosing this condition.
• To emphasize the importance of multimodal diagnostic approaches.

Main Methods:

• Case presentation of a 59-year-old male with a history of multiple myeloma.
• Utilized 18F-FDG PET/CT to assess hepatic and skeletal involvement.
• Performed liver biopsy for histopathological examination.
• Monitored response to systemic therapy.

Main Results:

• The patient presented with hepatomegaly and ascites.
• 18F-FDG PET/CT showed diffuse liver enlargement but no significant hepatic 18F-FDG uptake, indicating a hypometabolic myeloma phenotype.
• Liver biopsy confirmed diffuse sinusoidal infiltration by plasma cells, excluding amyloidosis.
• Hepatomegaly and ascites resolved with treatment, yet hepatic 18F-FDG uptake remained absent.

Conclusions:

• 18F-FDG PET/CT can be limited in detecting diffuse hepatic myeloma.
• Discordance between morphological and metabolic findings necessitates further investigation.
• Multimodal diagnostic strategies, including biopsy, are essential for accurate diagnosis and management of hepatic myeloma.