Ultrasound-guided fine needle aspiration cytology in the diagnosis of hepatic and pancreatic perivascular epithelioid cell tumors: A case series

Case report: Malignant epithelioid angiosarcoma in a Chinese female patient

Perivascular epithelioid cell tumors (PEComas) are mesenchymal tumors that exhibit characteristic epithelioid or spindle cell morphology and typically grow around blood vessels. These tumors are characterized by the expression of melanocytic and smooth muscle markers, such as HMB-45, Melan-A, and smooth muscle actin, indicating a dual differentiation phenotype. PEComas are extremely rare diseases, and patients typically have a very poor prognosis. Here, we report a case of malignant cutaneous PEComa with pulmonary metastasis in a Chinese female and review relevant literature. The patient underwent surgical resection of a soft tissue tumor in the left upper arm under general anesthesia, and the subsequent pathological findings suggested a tumor with perivascular epithelioid cell differentiation (PEComa). The patient received adjuvant chemotherapy and radiotherapy after surgical resection, along with monitoring through computed tomography (CT) scans. Three months later, pulmonary metastasis was detected, but both the cutaneous PEComa in the left upper limb and the pulmonary metastatic lesions were stably controlled under active management and treatment. This is a rare case worth reporting and studying, and therefore, we conducted a long-term follow-up, and we hope to provide help for the clinical treatment of PEComa.

Pancreatic PEComa, a not so uncommon neoplasm? Systematic review and therapeutic update

Pancreatic PEComas are extremely rare neoplasms with malignant potential, which mostly affect middle-aged women and are characterized by presenting melanocytic and myogenic markers in immunohistochemical analysis. There are no symptoms or pathognomonic imaging tests, so the diagnosis is established with the analysis of the surgical specimen or the FNA obtained with preoperative endoscopic ultrasound. The mean treatment consists on radical excision, adapting the intervention to the location of the tumor. To date, 34 cases have been described; however, more than 80% of them have been reported in the last decade, which suggests that it is a more frequent pathology than expected. A new case of pancreatic PEComa is reported and a systematic review of the literature is carried out according to the PRISMA guidelines with the aim of divulge this pathology, deepening its knowledge and updating its management.

Perivascular Epithelioid Cell Tumor (PEComa) of the Pancreas in a Patient with Ulcerative Colitis: A Case Report and Review of the Literature

Perivascular epithelioid cell tumors (PEComas) are mesenchymal tumors of peculiar cells that are focally associated with blood vessels, and generally have a distinctive bi-phenotypic expression of both smooth muscle and melanocytic markers. There are several entities in the PEComa family, including tumors that arise in the soft tissues and viscera. Frequently affected organs include the lungs (sugar tumors), uterus, broad ligament, colon, small bowel, liver, and pancreas. Ulcerative colitis (UC) has been associated with the development of tumors, especially colorectal and hepatobiliary carcinomas. Rare cases of UC have been reported in the PEComa family of tumors, but none in the pancreas. Here, we present a case study of a 27-year-old female patient with a history of UC who developed PEComa of the pancreas, a unique association that has not been previously reported. We also review reported cases of PEComas in the pancreas, as well as PEComas at all anatomic sites associated with UC.

Perivascular epithelioid cell tumor (PEComa) of the cystic duct

Perivascular epithelioid cell tumors, also known as PEComas, are rare mesenchymal tumors composed mainly of epithelioid cells found in perivascular tissue. PEComas occur most frequently in the kidney, uterus, the gastrointestinal tract, liver, and retroperitoneum; those originating in the biliary tree are extremely rare. We report a case of benign PEComa of the cystic duct with positive TFE3 staining on immunohistochemistry.A 66-year-old woman was referred for a 20 mm mass adjacent to the common bile duct discovered incidentally on abdominal ultrasound. Laboratory data including tumor markers were unremarkable. The tumor appeared to arise from the cystic duct, showed early enhancement, and compressed the common bile duct on imaging studies. Endoscopic ultrasound-guided fine-needle aspiration revealed round- and spindle-shaped atypical cells with eosinophilic cytoplasm and brown deposits suggestive of melanin granules. Histological examination of the resected specimen revealed a tumor consisting of epithelioid cells forming an alveolar structure, with melanin pigmentation. Immunohistochemistry was positive for HMB-45 and TFE3, consistent with benign pigmented PEComa of the cystic duct. Melanotic, myogenic, and TFE3 staining are helpful when diagnosing PEComas arising in unusual locations.

Application Value of Ultrasound-Guided Fine Needle Aspiration Cytological Examination and Ultrasound Evaluation

In this paper, chronic inflammatory cell infiltration was seen during this period. The reason for the false-positive result may be the atypical proliferation of cells caused by chronic inflammatory stimulation with malignant cytology. 12 cases of false negative results, including 2 cases of type I nodules, 10 cases of type III nodules, postoperative histology and pathology were papillary carcinoma, there are many reasons for false negative results, including the size of the nodules, the puncture operator, the technical level, internal tissue composition and properties of the nodules all affect the accuracy of puncture and cytopathology results. The satisfaction of puncture specimens of each group was calculated and compared. For thyroid nodules with the maximum diameter ≤5 mm, the satisfaction rate of puncture specimens was 87.2%, and the diagnostic sensitivity and accuracy of ultras guided fine needle aspiration biopsy were relatively low. Cytological results were in poor agreement with postoperative histological and pathological results, so it was recommended to take active follow-up for thyroid nodules with the maximum diameter ≤5 mm to reduce unnecessary puncture. The overall puncture success rate is relatively high, ≤10 mm low-echo nodules or even ≤5 mm nodules can be cytological puncture, especially the kind of close to the capsule, trachea and recurrent laryngeal nerve nodules, for the largest diameter of >5 mm, the satisfaction rate of puncture specimens is relatively high is 93.2%. Moreover, the sensitivity and accuracy of ultrasound guided fine needle aspiration biopsy were relatively high, and the cytological results were in good agreement with the postoperative histological and pathological results. Therefore, it was feasible to confirm the diagnosis of suspected malignant nodules by ultrasound. The diagnostic in each group and the consistency between cytological diagnosis and histological diagnosis were analyzed by comparing the histological and pathological results after surgery. Ultrasound-guided fine needle aspiration biopsy can be used more effectively in clinical practice.

Cytopathology of extra-renal perivascular epithelioid cell tumor (PEComa): a series of 7 cases and review of the literature

INTRODUCTION

Perivascular epithelioid cell tumor (PEComa) is a family of rare mesenchymal tumors consisting of histologically and immunohistochemically distinctive perivascular epithelioid cells. Relatively little is known about the cytopathology of extra-renal PEComas. Because of a considerable range of morphology and their rarity, accurate cytologic classification can be challenging. We evaluated cytologic characteristics and diagnostic pitfalls of extra-renal PEComas on fine-needle aspiration (FNA).

MATERIALS AND METHODS

We performed a retrospective search in our cytopathology and surgical pathology database for cases diagnosed as PEComa that had corresponding cytology specimens from 3 medical institutions. All available cytopathology specimens were reviewed. We evaluated cytologic characteristics and recorded histologic diagnoses and immunohistochemical stains.

RESULTS

Seven FNA specimens from 6 patients were identified, and cytologic diagnoses were made in all cases as follows: PEComa (4 cases), most consistent with PEComa (1 case), malignant neoplasm (1 case), and hepatocellular carcinoma (1 case). Most specimens were moderately to highly cellular. Cell distribution occurred as tissue fragments with background proliferating capillaries. Most smears were composed of epithelioid cells showing mild to moderate anisonucleosis, abundant eosinophilic cytoplasm, well-defined borders, intranuclear pseudoinclusions, and prominent nucleoli. A combination of myoid and melanocytic markers was expressed in 6 cases except 1 case, which was called hepatocellular carcinoma.

CONCLUSIONS

This was the largest FNA series for extra-renal PEComas to date. Our study highlights some common cytomorphologic characteristics of PEComa with which cytopathologists should be familiar. In the right clinical and radiologic context, and with the aid of immunohistochemistry, a definitive diagnosis can be achieved.