Objective: To investigate the clinicopathological features of perivascular epithelioid cell tumor (PEComa) of the lung. Methods: Eight PEComa cases of the lung diagnosed at the First Affiliated Hospital of Soochow University, Suzhou, China from July 2008 to December 2021 were collected and subject to immunohistochemical staining, fluorescence in situ hybridization and next generation sequencing. The relevant literature was reviewed and the clinicopathological features were analyzed. Results: There were 5 males and 3 females, aged from 18 to 70 years (mean 39 years). There were 3 cases of the right upper lung, 3 cases of the left lower lung, 1 case of the left upper lung and 1 case of the right middle lung. Seven cases were solitary and 1 case was multifocal (4 lesions). Seven cases were benign while one was malignant. The tumors were all located in the peripheral part of the lung, with a maximum diameter of 0.2-4.0 cm. Grossly, they were oval and well circumscribed. Microscopically, the tumor cells were oval, short spindle-shaped, arranged in solid nests, acinar or hemangiopericytoma-like patterns, with clear or eosinophilic cytoplasm. The stroma was rich in blood vessels with hyalinization. Coagulated necrosis and high-grade nuclei were seen in the malignant case, and calcification was seen in 2 cases. Immunohistochemically, the tumor cells were positive for Melan A (8/8), HMB45 (7/8), CD34 (6/8), TFE3 (4/7), and SMA (3/8). All cases were negative for CKpan and S-100. TFE3 (Xp11.2) gene fusion was examined using the TFE3 break-apart fluorescence in situ hybridization in 5 cases, in which only the malignant case was positive. The next generation sequencing revealed the SFPQ-TFE3 [t(X;1)(p11.2;p34)] fusion. Follow-up of the patients ranged from 12 to 173 months while one patient was lost to the follow-up. The malignant case had tumor metastasis to the brain 4 years after the operation and then received radiotherapy. Other 6 cases had no recurrence and metastasis, and all the 7 patients survived. Conclusions: Most of the PEComas of the lung are benign. When there are malignant morphological features such as necrosis, high-grade nuclei or SFPQ-TFE3 gene fusion, close follow-up seems necessary.
Male ; Female ; Humans ; In Situ Hybridization, Fluorescence ; Perivascular Epithelioid Cell Neoplasms/pathology* ; Lung/pathology* ; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/genetics* ; Necrosis ; Biomarkers, Tumor/analysis*

Objective: To investigate hepatic perivascular epithelioid cell tumor (PEComa) diagnosis and treatment plan. Methods: 24 cases diagnosed with PEComa clinical manifestations, serum alpha fetoprotein (AFP), carcinoembryonic antigen (CEA), carbohydrate antigen 199 (CA199), imaging findings, surgical methods, postoperative hospital stay, pathological results and prognosis were analyzed retrospectively from September 2015 to September 2020. Results: Majority of patients were females (79.2%), aged 41.5±11.4 years. Tumors were predominantly located in the right liver (50.0%). 76.7% of the cases were mostly clinically asymptomatic. AFP, CEA and CA199 indices were all negative. CT mostly showed low density tumor in the plain scan phase, enhanced in the enhancement phase, and enhanced and weakened in portal venous and equilibrium phase (66.7%). MRI manifestations of most tumors were hypointense on T₁WI and hyperintense on T₂WI (72.7%). B-ultrasound mostly showed hyperechoic mass in the tumor area with punctate vascular shadow (52.9%). Postoperative hospital stay was 9.0±2.4 days for laparoscopic surgery patients (n=13), 13.4±6.3 days for traditional laparotomy (hereinafter referred to as laparotomy, n=10), and 3 days for 1 patient with microwave ablation. All postoperative pathological results were positive for HMB45 and Melan-A. Follow-up results: 21 cases survived normally, with no tumor recurrence in the recent physical examination; two cases had tumor recurrence and they died two and three years after surgery, and one case was lost to follow-up. Conclusion: Hepatic PEComa more commonly occurs in middle-aged women, with no specific features for tumor markers and clinical manifestations. Some imaging findings are specific, so its features can be combined as a basis for diagnosis. Postoperative pathological examination results can confirm the diagnosis. Therefore, surgery remains the initial treatment plan. Microwave ablation and laparoscopic surgery are recommended as the preferred option because of shorter hospital stays and less trauma than open surgery.
Adult ; Biomarkers, Tumor/analysis* ; Carbohydrates ; Carcinoembryonic Antigen ; Female ; Humans ; Liver/pathology* ; MART-1 Antigen ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Perivascular Epithelioid Cell Neoplasms/surgery* ; Retrospective Studies ; alpha-Fetoproteins

Basic Helix-Loop-Helix Leucine Zipper Transcription Factors/genetics* ; Biomarkers, Tumor ; Humans ; Perivascular Epithelioid Cell Neoplasms/surgery* ; Stomach

Carcinoma, Papillary/surgery* ; Humans ; Parapharyngeal Space ; Perivascular Epithelioid Cell Neoplasms ; Thyroid Cancer, Papillary ; Thyroid Neoplasms/surgery*

Perivascular epithelioid cell tumor (PEComa) is a very rare mesenchymal tumor with a distinctive morphology and immunophenotype. PEComas usually harbor TSC2 alterations, although TFE3 translocations, which occur in MiT family translocation renal cell carcinoma and alveolar soft part sarcoma, are also possible. We recently experienced a case of PEComa with TFE3 expression arising in the breast. An 18-year-old female patient presented with a right breast mass. Histologically, the tumor consisted of epithelioid cells with alveolar structure and showed a diffuse strong expression of HMB45 and TFE3. TSC2 was preserved. Melan A and smooth muscle actin were negative. To our knowledge, this is the first Korean case of PEComa of the breast that intriguingly presented with TFE3 expression.
Actins ; Adolescent ; Breast ; Carcinoma, Renal Cell ; Epithelioid Cells ; Female ; Humans ; MART-1 Antigen ; Muscle, Smooth ; Perivascular Epithelioid Cell Neoplasms ; Sarcoma, Alveolar Soft Part

Epithelioid angiomyolipoma (EAML) of liver is a rare neoplasm. Hepatic EAML is often misdiagnosed as other neoplasms such as hepatocellular carcinoma due to non-specific clinical and radiologic features. The morphologic features under microscope and immunohistochemistry staining profile are important in the diagnosis EAML. Here, we report a case of 52-year-old man who found 1.2 cm mass in liver by routine checkup. On the impression of hepatocellular carcinoma, lateral sectionectomy of the liver was done. Microscopically, the tumor is composed of predominant epithelioid cells with vascular component and foamy cells. These cells were positive for HMB45, MelanA, and smooth muscle actin and negative for epithelial membrane antigen. The final diagnosis was hepatic EAML.
Actins ; Angiomyolipoma* ; Carcinoma, Hepatocellular ; Diagnosis ; Epithelioid Cells ; Humans ; Immunohistochemistry ; Liver* ; MART-1 Antigen ; Middle Aged ; Mucin-1 ; Muscle, Smooth ; Perivascular Epithelioid Cell Neoplasms

Hepatic perivascular epithelioid cell tumors (PEComas) are very rare. We report a primary hepatic PEComa with a review of the literature. A 56-year-old women presented with a nodular mass detected during the management of chronic renal failure and chronic hepatitis C. Diagnostic imaging studies suggested a nodular hepatocellular carcinoma in segment 5 of the liver. The patient underwent partial hepatectomy. A brown-colored expansile mass measuring 3.2×3.0 cm was relatively demarcated from the surrounding liver parenchyma. The tumor was mainly composed of epithelioid cells that were arranged in a trabecular growth pattern. Adipose tissue and thick-walled blood vessels were minimally identified. A small amount of extramedullary hematopoiesis was observed in the sinusoidal spaces between tumor cells. Tumor cells were diffusely immunoreactive for human melanoma black 45 (HMB45) and Melan A, focally immunoreactive for smooth muscle actin, but not for hepatocyte specific antigen (HSA).
Actins ; Adipose Tissue ; Blood Vessels ; Carcinoma, Hepatocellular ; Diagnostic Imaging ; Epithelioid Cells* ; Female ; Hematopoiesis, Extramedullary ; Hepatectomy ; Hepatitis C, Chronic ; Hepatocytes ; Humans ; Kidney Failure, Chronic ; Liver ; MART-1 Antigen ; Melanoma ; Middle Aged ; Muscle, Smooth ; Perivascular Epithelioid Cell Neoplasms

No abstract available.
Orbit* ; Perivascular Epithelioid Cell Neoplasms*

Angiomyolipomas are hamartomatous lesions consisting of smooth muscle bundles, thick-walled blood vessels, and mature adipocytes. They are usually found in the kidneys of tuberous sclerosis patients and more rarely in other organs, such as the liver, the oral cavity, the sinonasal tract, the heart, the large intestines, the lungs, and the skin. Cutaneous angiomyolipoma has shown to be very rare and generally occurs at the ends of the digits, the elbows, the ears, and the nose. Herein, we report the first documented case of angiomyolipoma of the glabellar region.
Adipocytes ; Angiomyolipoma* ; Blood Vessels ; Ear ; Elbow ; Heart ; Humans ; Intestines ; Kidney ; Liver ; Lung ; Mouth ; Muscle, Smooth ; Nose ; Perivascular Epithelioid Cell Neoplasms ; Skin ; Tuberous Sclerosis

Perivascular epithelioid cell tumors or PEComas can arise in any location in the body. However, a limited number of cases of gastric PEComa have been reported. We present two cases of gastric PEComas. The first case involved a 62-year-old woman who presented with a 4.2 cm gastric subepithelial mass in the prepyloric antrum, and the second case involved a 67-year-old man with a 5.0 cm mass slightly below the gastroesophageal junction. Microscopic examination revealed that both tumors were composed of perivascular epithelioid cells that were immunoreactive for melanocytic and smooth muscle markers. Prior to surgery, the clinical impression of both tumors was gastrointestinal stromal tumor (GIST), and the second case was erroneously diagnosed as GIST even after microscopic examination. Although gastric PEComa is a very rare neoplasm, it should be considered in the differential diagnosis of gastric submucosal lesions.
Aged ; Diagnosis, Differential ; Epithelioid Cells* ; Esophagogastric Junction ; Female ; Gastrointestinal Stromal Tumors ; Humans ; MART-1 Antigen ; Middle Aged ; Muscle, Smooth ; Perivascular Epithelioid Cell Neoplasms ; Stomach Neoplasms ; Stomach*