Malignant neoplasm of perivascular epithelioid cells of the liver
ABSTRACT Neoplasms of perivascular epithelioid cells (PEComas) have in common the coexpression of muscle and melanocytic immunohistochemical markers. Although this group includes entities with distinct clinical features, such as angiomyolipoma, clear cell sugar tumor of the lung, and lymphangioleiomyomatosis, similar tumors have been documented in an increasing diversity of locations. The term PEComa is now generally used in reference to these lesions that are not angiomyolipomas, clear cell sugar tumors, or lymphangioleiomyomatoses. While most reported PEComas have behaved in a benign fashion, malignant PEComas have occasionally been documented. We present a case of hepatic PEComa with benign histologic features, which nonetheless presented with metastases to multiple sites nearly 9 years later. This case represents the second documented malignant PEComa of the liver, as well as the longest follow-up of a surviving patient with a malignant PEComa, emphasizing both the need for criteria that more accurately predict the behavior of PEComas and the necessity of long-term follow-up of patients with PEComas.
- [Show abstract] [Hide abstract]
ABSTRACT: Hepatic angiomyolipoma (AML) is known as a rare benign tumor with invasive growth. In the past, some of these tumors were misdiagnosed as hepatocellular carcinomas, because of the similar pattern on imaging studies. Recently, correct diagnoses have been increasing, with the development of HMB-45 immunohistochemical staining, and it appears that the majority of these tumors behave as benign tumors. However, there are not a few cases which have resulted in fatal courses because of recurrence and metastasis of the tumor. The clinical features and signs of the malignant potential of this tumor are unknown; thus, the management and treatment of the tumor are still controversial. Here in this article, we report a case of hepatic AML which showed a size increase of 175% in 1year, and portal vein thrombosis detected by angiography. During a follow up of 3years after a curative hepatic lobectomy, no metastasis or recurrence was seen. Review of the literature suggests that portal vein thrombosis could be one of the markers of the malignant potential and transformation of this tumor. Therefore, in this paper, we recommend surgical treatment of hepatic AML in which there is a strong suspicion of portal vein thrombosis. KeywordsHepatic angiomyolipoma-Portal vein thrombosis-HMB-45-Malignant-PEComaClinical Journal of Gastroenterology 04/2010; 3(2):104-110. DOI:10.1007/s12328-010-0136-2
- [Show abstract] [Hide abstract]
ABSTRACT: Four cases of malignant PEComas were stained with smooth muscle actin, muscle specific actin, desmin, human melanoma black-45, melan-A, microphthalmia transcription factor, S100 and cyclin D1. One case was studied by electron microscopy (EM). Tumour locations were the thigh, elbow, retroperitoneum and bladder in association with a urachal cyst. There were two men and two women; the average age was 51.3 years, and the size ranged from 5.0-23.0 cm. In three cases, 50-95% of the tumour was composed of pleomorphic sarcomatous areas. All cases had at least focal clear-cell areas. One case showed a continuous single layer of perivascular clear cells remote from the tumour, transitioning to invasive nests and to PEComa. EM demonstrated these cells in apposition to and in direct contact with the abluminal surface of the basal lamina of the capillaries. We suggest the term "pecosis" for these areas. All cases were positive for two or more melanocytic markers and for at least one actin. S100 and desmin were focally positive in one case. Cyclin D1 was positive in 3:4 cases. Four cases of malignant PEComa are described with the existence of a unique lesion (pecosis) in one case. These tumours may manifest largely as sarcomas appearing to be undifferentiated and should be considered in their differential diagnosis.Archiv für Pathologische Anatomie und Physiologie und für Klinische Medicin 05/2007; 450(4):463-70. DOI:10.1007/s00428-007-0378-7 · 2.56 Impact Factor
- Gastroentérologie Clinique et Biologique 05/2007; 31(5):555-556. DOI:10.1016/S0399-8320(07)89428-0 · 1.14 Impact Factor