Sonazoid-enhanced ultrasonography and pathologic characters of CD68 positive cell in primary hepatic perivascular epithelioid cell tumors: A case report and literature review

Perivascular epithelioid cell tumor (PEComa) is a mesenchymal tumor rarely described in the liver. Sonazoid is a new ultrasound contrast with both vascular and post-vascular phases due to the uptake of Kupffer cell. CD68 is a defined immunohistorical staining marker for macrophage including Kupffer cell. No previous cases have been reported to reveal Kupffer images in the post-vascular phase by using Sonazoid and pathologic characters of CD68 positive cell in PEComa. Herein, we describe the first case to present Sonazoid contrast-enhanced ultrasonography (CEUS) findings in Kupffer images and CD68 positive cell in hepatic PEComa which may lead to rethink of the phagocytic properties of macrophages.

Rapidly enlarging malignant abdominal PEComa with hepatic metastasis: a promising initial response to sirolimus following surgical excision of primary tumor

Intra-abdominal perivascular epithelioid cell tumors (PEComas) are rare mesenchymal tumors. Although no effective therapies have been agreed upon, mTOR inhibitors are currently being investigated as a potential therapy for this extremely rare tumor. We present a case of a 64-year-old male found to have a large intra-abdominal PEComa with multiple metastatic lesions in the liver. Patient underwent surgical resection of the primary lesion in the abdomen and sigmoid colon followed by adjuvant therapy with the mTOR inhibitor, sirolimus. Initial response was noted with a decrease in size and number of lesions found in the patient’s liver. After 8 months of therapy, restaging imaging showed disease progression in the liver lesions. Patient subsequently failed treatments with pazopanib, investigational therapy TAK-228 (Sapanisertib) and nivolumab and ipilimumab. Overall the patient died after 22 months of disease. PEComas generally follow a benign course. This case is a much rarer entity given the malignant features/outcome.