Fine needle aspiration cytology of mesenchymal hamartoma of liver mimicking hepatoblastoma: A case report

Abstract

Fine-needle aspiration cytology (FNAC) is an effective tool for early and quick diagnosis of malignant and metastatic liver masses. However, diagnosing a benign liver tumor on cytology is a challenging task as they are rarely assessed on cytology and also due to the limitations of the procedure. Mesenchymal hamartoma is an uncommon benign pediatric liver tumor and difficult to diagnose on cytology. We describe here a case of a child who presented with a huge liver mass and clinical suspicion of hepatoblastoma. The child underwent blind FNA, and was diagnosed as mesenchymal hamartoma based on the cytological features. A biopsy was performed subsequently which confirmed the same and then he underwent surgical resection of the tumor.The patient had an uneventful recovery and is disease free on follow up.

Surgical Pathology Diagnostic Pitfalls of Hepatoblastoma

“…19 , 21 FNA has been described in the diagnostic workup of mesenchymal hamartoma: HB is a major differential for the slightly less common mesenchymal hamartoma and has its own distinctive cytological features, such as clusters of tumor cells showing acinar and trabecular patterns, small round tumor cells with a high nuclear to cytoplasmic ratio, hyperchromatic nuclei with prominent nucleoli, and the presence of extramedullary haemopoiesis. 17 , 22 Due to the heterologous nature of both HB and mesenchymal hamartoma, and the narrow sampling potential of FNA, these two lesions with vastly different clinical trajectories can be mistaken for one another. FNA may miss the spindle cell mesenchymal element classically associated with mesenchymal hamartoma.…”

“…In addition, mesenchymal hamartoma may be associated with increased serum AFP, further obfuscating the clinical distinction. 20 , 22 , 23 Taking this into account, FNA is not considered adequate for diagnosis of HB. The current recommendation for diagnosis of HB is biopsy if surgical resection in the first instance is not an option.…”