Primary Invasive Ductal Carcinoma of the Breast Occurring in a Patient With a History of Hepatocellular Carcinoma Developing From Focal Nodular Hyperplasia: A Case Report and Literature Review.

The risk of developing another primary malignancy after an initial liver cancer diagnosis is rare, and the management of multiple primary cancers is not typically discussed. Focal nodular hyperplasia (FNH) is considered a benign tumor, but there have been cases reported that describe hepatocellular carcinoma (HCC) arising from or within FNH. Here, we report a woman in her 70s who had a longstanding history of FNH, later found to be HCC upon resection, who also developed invasive ductal carcinoma. She had no family history of cancer and no genetic testing results were available. Each of her cancers was managed independently, hepatectomy for HCC and neoadjuvant therapy followed by mastectomy for her breast carcinoma. This case demonstrates that the diagnosis of FNH based on radiographic imaging may necessitate a biopsy to confirm diagnosis for a symptomatic patient or those with lesions suspicious for malignancy. It also showcases the importance of close follow-up after a primary cancer diagnosis for the possibility of another primary malignancy emerging. Fresh tissue biopsy for new lesions could help determine primary malignancy or metastasis. Genetic sequencing may help identify driver mutations or genetic alterations that can be targeted.