Fine needle aspiration cytology of mesenchymal hamartoma of the liver - A case report

BACKGROUND: Mesenchymal hamartoma (MH) of the liver constitutes the third o r fourth most common tumor of the liver in childhood and occurs most common ly in the first two years of life. MHs of the liver are seldom aspirated, a nd reports on the role of fine needle aspiration (FNA) in the diagnosis of MH are scarce. Clinically, cytologically and evert histologically, MH can b e mistaken for a number of reactive and neoplastic hepatic lesions that may occur in children tinder 2 years of age. CASE: A 10-month-old Pakistani female presented with a history of a right-s ided, nonpainful abdominal swelling. Abdominal computed tomography showed a large, partly solid and partly cystic, heterogeneous hepatic mass. FNA cyt ology showed clusters of both epithelial and mesenchymal/spindle-shaped cel ls with pieces of loose connective tissue. A cytologic differential diagnos is of mesenchymal hepatic hamartoma and hepatoblastoma of the possible mixe d mesenchymal/epithelial subtype was rendered. The histopathologic diagnosi s of the resected tumor mass was benign mesenchymal hamartoma of the liver. CONCLUSION: In children under 2 years of age who present with partly solid and partly cystic hepatic masses, the possibility of MH gf the liver should be considered. FNA has a role in the diagnosis of MH. The cytopathologist should be aware of the patient's age, radiologic features and cytologic app earances oft his rare, benign neoplasm. Histologic examination of tru-cut b iopsies and immunohistochemical stains can help to exclude other pediatric neoplasms that may show cytologic features similar to or mimicking those of MH.