Hepatic epithelioid angiomyolipoma with trabecular growth pattern: A mimic of hepatocellular carcinoma on fine needle aspiration cytology

Abstract

Epithelioid angiomyolipomas (AMLs) of the liver are rare tumors with imaging and cytologic features overlapping with those of hepatocellular carcinomas. We report the fine needle aspiration and core biopsy findings of an epithelioid AML in the right hepatic lobe of a 32-year-old female with tuberous sclerosis. She had undergone renal transplantation 8 years previously after bilateral nephrectomy for renal AMLs and a 3-cm chromophobe renal cell carcinoma. Hepatocellular carcinoma was suspected during the initial cytologic and histologic examination based on the presence of numerous large polygonal cells with ample finely vacuolated or granular cytoplasm, low nucleocytoplasmic ratio, and mild nuclear pleomorphism in the smears, as well as a distinctive trabecular histologic pattern in the core biopsies. Immunoperoxidase stains showed that the neoplastic cells were negative for cytokeratins and positive for HMB45, Melan-A, and smooth muscle actin, establishing the diagnosis of epithelioid AML. To determine the distinguishing cytomorphologic features between epithelioid AML and HCC, we have compared the cytologic features of 15 cases of hepatic AML reported in the literature, including the present case, to the FNA cytologic findings of 38 consecutive cases of HCC diagnosed at out institution.

Hepatic PEComa: a potential pitfall in the evaluation of hepatic neoplasms

“…FNA has been found to be useful in establishing an early diagnosis of hepatic PEComa 9. In this case, however, the neoplastic cells of PEComa were not recognised as such in the FNA or core needle biopsy due to the unusual amount of obscuring haemorrhage, the small number of tumour cells present and their resemblance to degenerative or reactive hepatocytes.…”

“…The liver is said to be second only to the kidney as the most common visceral site of PEComa,2 but since first described in 1976,3 about 200 cases of hepatic PEComa have been reported,4 most of which have been classic AML with only 16 cases identified as having monotypic epithelioid morphology,4 – 9 as in our patient. Herein, we report the case of a man who, after an inconclusive fine-needle aspiration and core needle biopsy, underwent partial liver resection for a possible primary liver tumour, which on final pathological examination presented a broad differential diagnosis of primary and secondary epithelioid and clear cell neoplasms and was found by immunohistochemical evaluation to be PEComa.…”

Gd-EOB-DTPA-enhanced and diffusion-weighted magnetic resonance findings in hepatic epithelioid angiomyolipoma: A case report

“…Epithelioid AML has uncertain malignant potential, and there have been rare cases of tumor recurrence, vascular invasion and metastases (10)(11)(12). Surgical resection should be considered for all symptomatic patients, who should be followed up after surgery.…”

Application of Immunohistochemistry in Gastrointestinal and Liver Neoplasms: New Markers and Evolving Practice

“…Some of the most notorious mimickers of HCC include adrenocortical carcinoma, renal cell carcinoma, clear cell sarcoma, melanoma, large cell neuroendocrine carcinoma, and angiomyolipoma. [19][20][21] In addition, poorly differentiated HCC and some HCC variants may be difficult to discern based on morphology alone. 22 In these circumstances, IHC is not only helpful but necessary for accurate diagnosis.…”