PMC3042371_01
CT appearance of PEComa: axial (a), coronal (b) and sagittal (c) reconstructions. CT of the abdomen showed a 7 cm lesion in the right lobe of the liver with multiple ovular lesions of 0.5-3.5 cm along right triangular ligament, hypoattenuating relative to the surrounding hepatic tissue with minute calcifications. Hypodense lesions along right triangular ligament and capsular profile of falciform ligament were additionally documented. In the thorax CT images, abnormal lymph nodes of 2,8 cm in length were observed along internal right mammary chain, anterior mediastinum and aorta-lung interface. Multiple nodular lesions of the lung were documented in the right hemi-thorax.
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F1
The radiological images demonstrated right fluid pleurical collection with passive collapse of the lung inferior lobe, abnormal lymph nodes of the right internal mammary chain and anterior mediastinum (Figure 1). Hemoperitoneum was also documented (Figure 1).
Intraoperative appearance of PEComa. Multiple lobulated nodules containing hemorrhagic fluid on the hepatic capsule, peritoneum surface (a) and omentum (b) associated with hemoperitoneum were observed. The surgical procedure consisted in toilette of peritoneal cavity, omentectomy and hemostasis. In our case, it was impossible to perform an oncological curative surgery.
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F2
At surgery, the hepatic mass, the multiple subcapsular hematomas, and the hemoperitoneum were confirmed (Figure 2).
Histological and immunohistochemical profile of PECs. Tumor cells showed severe atypia, cytological pleomorphism, high mitotic activity and atypical mitotic figures (Hematoxylin-Eosin, x40)(a). Both epithelioid and spindle cells were diffusely positive for HMB-45 (x200)(b) and Melan-A (x63)(c) antigens in the cytoplasm. The prominent capillary network, but not tumor cells, showed CD34 positive staining (x40)(d).
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F3
Based on this specific immunophenotype profile, diagnosis of PEComa was made (Figure 3-4).
Histological and immunohistochemical profile of PECs. Tumor cells showed marked coagulative necrosis (Hematoxylin-Eosin, x40) (a). In PECs, SMA had a focally cytoplasmic positivity (x40)(b). Nuclear MIB-1 reactivity was documented in PECs (x200)(c). We observed a strong and diffuse membrane reactivity for CD31 in tumor cells (x40)(d). The tumor was negative for all other markers mentioned, including S-100, CKAE1/AE3, CK5, CD30.
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Based on this specific immunophenotype profile, diagnosis of PEComa was made (Figure 3-4).