Fine needle aspiration biopsy of hepatic focal fatty change. A report of two cases

In rare instances, hepatic steatosis produces a circumscribed, nodular lesion described as focal fatty liver change (FFLC). The ultrasonographic and computed tomographic patterns are those of an isointense or hyperechoic nodule, sometimes simultating metastasis. CASES: Fine needle aspiration biopsy was performed under ultrasonographic control in two men aged 65 and 67 years who had previously undergone emicolectomy and gastrectomy for adenocarcinoma. Routine hepatic ultrasound showed solitary nodules, of 3 and 4 cm in diameter. The microscopic patterns were similar and highly cellular in both cases. Cells were isolated or organized in sheets and characterized by large, intracytoplasmic, clear vacuoles that displaced nuclei to the periphery of the cells, flattening them against the cytoplasmic membrane and giving these cells a signet-ring appearance. Nuclei were generally round and nucleolated or dense and hyperchromatic when flattened onto the cytoplasmic membrane. Normal hepatocytes were interspersed in the background, and in some areas of the slides hepatocytes with one or more small intracytoplasmic vacuoles with cytologic features intermediate between those of vacuolated cells and normal hepatocytes were present. Digested periodic acid-Schiff staining, performed on destained, fixed smears, gave negative results. The cytologic diagnosis was FFLC. Clinical and echographic follow-up confirmed the cytologic diagnosis. CONCLUSION: The ultrasonographic and microscopic features of FFLC may mimic those of metastasis. A proper cytologic diagnosis may contribute to the diagnostic workup of these rare lesions.