Metastatic hepatocellular carcinoma to the bone diagnosed by fine needle aspiration in a veteran population

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide and it may present initially with extrahepatic spread in 5%-15% cases. It most commonly metastasizes to lungs, lymph nodes and adrenal glands. Skeletal metastases from HCC are uncommon and carry a very poor prognosis.

We retrospectively reviewed all fine needle aspiration (FNA) specimens of metastatic HCC at our institution from January 1994 to March 2021 using the SNOMED search computer option. Relevant clinical information was obtained from the review of patient's electronic medical records.

There were 36 FNAs of metastatic HCC over a period of 27 years. Six patients (16.7%) were found to have skeletal metastases. All six patients were males with a median age of 59 years (54-71 years) and their lesions were osteolytic. The most common site of metastases was vertebra (3/50%). Most patients (67%) had bone metastases as an initial presentation, without prior history of HCC. The mean survival after the diagnosis of skeletal metastases was only 8 months.

Detection of extrahepatic HCC to bone is important to avoid any unwanted surgical intervention. In our patient population, the most common site of skeletal metastases from HCC was vertebra, therefore in FNAs of vertebral lytic masses, metastatic HCC should be considered. On FNA, extrahepatic metastases of HCC can mimic other poorly differentiated tumors. They behave in an aggressive fashion, resulting in a grim prognosis. Cytological substrates can be used for future molecular testing, if needed.