Search

Objective: To evaluate the dynamic CT, MRI, ultrasonography, and pathologic features of hepatic perivascular epithelioid cell tumor (PEComa), improving the understanding and diagnosis of the tumor. Methods: A retrospective analysis of CT, MRI, ultrasonography, and pathologic features of 7 hepatic PEComas diagnosed by pathology during 1st January 2005 to 1st September 2011 in our hospital. Results: The performance of dynamic CT, MRI, and ultrasonography revealed that lesions were regular masses with well-defined borders, the maximum diameters were 2.5-8.5 cm (mean = 4 cm), density was homogeneous, contrast-enhanced CT and MRI showed the lesions were significantly and heterogeneously enhanced on arterial phase, less enhanced on portal venous phase, and slightly hypodense on delayed phase. One patient had multiple hepatic lesions and had delayed enhancement. There were no backgrounds of hepatitis and cirrhosis, enlarged lymph nodes, or distant metastases. Pathology showed the gross appearance of the tumor was smooth. Tumor cells were round or polygonal, with clear boundaries and clear membranes, and had abundant translucent cytoplasm. Nuclei were round, with medium size. Tumor cells were epithelial-like cells and arranged in dense sheets. Immunohistochemistry showed that most of them were positive in HMB45 and MelanA, S-100, SMA, while negative in CgA, Syn, CK, CD117, CD10, and CD34. Conclusions: Dynamic CT, MRI, ultrasonography, and pathology of PEComa had some characteristics of benign tumor's performance. Enhanced scan showed PEComa quickly enhanced on arterial phase and enhanced less on portal venous phase. Knowing these characteristics could help to improve the understanding and diagnosis of hepatic PEComa. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the dynamic CT, MRI, and clinicopathologic characteristics of rare hepatic malignant tumors (HRMTs), improving the understanding and diagnosis of the tumors., Methods: A retrospective analysis of 54 cases of HRMTs diagnosed by pathology in our hospital during January 1, 2005 to September 1, 2011., Results: The types of tumors included hepatic sarcoma (n = 8), malignant lymphoma (n = 4), malignant fibrous histiocytoma (MFH, n = 7), malignant melanoma (MM, n = 4), squamous cell carcinoma (SCC, n = 5), primary clear cell carcinoma of the liver (PCCCL, n = 7), stromal tumors (ST n = 4), hepatoblastoma (HB, n = 8), carcinoid (n = 6), primary primitive neuroectodermal tumor (pPNET, n = 1). Age of the patients ranged from 1 to 79 years (mean = 46.7 years). There were more men in this group (34/54). Symptoms of HRMTs show no specificity. Except PCCCL and HB, the serum AFP of most HRMTs was negative. 43 patients had a single hepatic mass, and 11 patients had multiple hepatic masses. Diameters ranged from 2 to 15 cm (mean = 7.7 cm). Precontrast CT revealed that most masses had uneven density (n = 46) and ill-demarcated margin (n = 37). Enhanced CT showed most lesions unevenly enhanced (n = 49), of which PCCCL had a prompt enhancement in the arterial phase and rapid wash-out on the portal venous phase and delayed phase; malignant lymphoma and ST had slight enhancement, MFH and undifferentiated embryonal sarcoma had gradual delayed enhancement. Most masses had low-signal on T1WI and high-signal on T2WI, while MM had high-signal on T1WI and low-signal on T2WI., Conclusions: Although there is frequent overlap in the CT, MRI, and clinicopathologic appearances between the rare malignant tumors, some HRMTs have characteristic imaging features that can suggest a specific diagnosis.