Malignant Perivascular Epithelioid Cell Neoplasm (PEComa) of the Pelvis: A Case Report

Management Strategies for Adults with Locally Advanced, Unresectable or Metastatic Malignant Perivascular Epithelioid Cell Tumor (PEComa): Challenges and Solutions

PEComa (PEC tumor; perivascular epithelioid cell tumors) is a rare group of tumors of mesenchymal origin composed of perivascular epithelioid cells (PEC) with features of melanotic and smooth muscle differentiation. In this article, we would like to present the current treatment options for this group of tumors. PEComas are classified as tumors of uncertain malignant potential because recurrences occur after radical treatment. The primary treatment is surgical resection with negative margins. Due to the different locations of the tumors, often the cooperation of multispecialty surgeons is required during the operations. In locally advanced cases, cytoreduction and HIPEC may be effective but still are an experimental treatment. For nonresectable PEComa chemotherapy, mTOR inhibitors and VEGFR inhibitors are used.

Perivascular epithelioid cell tumour-mimicking retroperitoneal leiomyosarcoma

A young man in his 40s was evaluated in the emergency department for abdominal and right flank pain. A CT scan of the abdomen and pelvis showed a solid, well-circumscribed lesion measuring 7.1×8.1×5.4 cm, which was arising from the retroperitoneum and extending from the third portion of the duodenum towards the right kidney. A percutaneous core biopsy was obtained, demonstrating an atypical smooth muscle neoplasm suggestive of a low-grade leiomyosarcoma. The patient underwent surgery for an en-block resection of the mass and the final pathology confirmed a perivascular epithelioid cell neoplasm without significant pleomorphism, mitosis or necrosis. Our case adds to the small number of perivascular epithelioid cell tumour cases reported in the literature and we present it in order to increase our understanding of this tumour and to assist in its appropriate diagnosis and management.

Unusual paediatric sigmoid perivascular epithelioid cell tumour with regional lymph node metastasis treated using gemcitabine and docetaxel: a case report and literature review

Perivascular epithelioid cell tumour (PEComa) is an extremely rare neoplasm with distinctive morphology and specific expression of immunohistochemical markers. The lesion is typically diagnosed in middle-aged women, with few reports of paediatric cases, and there is no standardized treatment for the tumour type. Here, the case of a 17-year-old female, who presented with painless haematochezia for 2 days and was diagnosed with gastrointestinal PEComa of the sigmoid colon with regional lymph node metastasis after serial examination, is presented. She was treated by surgical resection of the tumour and cytotoxic chemotherapy comprising 900 mg/m2 gemcitabine and 100 mg/m2 docetaxel every 3 weeks for six cycles. Haematochezia did not recur, and complete response was achieved, with progression-free survival at the 24-month follow-up examination. Surgical resection with adjuvant conventional cytotoxic chemotherapy may be considered as an option for treating gastrointestinal PEComa.

Soft Tissue Perivascular Epithelioid Cell Tumour: An Unusual Finding

Perivascular epithelioid cell tumour (PEComa) is a rare mesenchymal tumour made up of clear perivascular cells with epithelioid characteristics, which co-expresses muscle and melanocytic markers with a component of spindle cells, like sarcoma and variety of other tissues. This time, we present the case of a young patient with a tumour in the dorsal region of progressive growth, compatible with PEComa of soft tissue after histopathological and immunohistochemical analysis.

Perivascular epithelioid cell tumor of the pancreas: case report and literature review

Neoplasms with perivascular epithelioid cell differentiation (PEComas) of the pancreas are rare, and only 22 cases have been reported globally. Therefore, clinician and pathologist knowledge of this tumor's biologic behavior and molecular genetics has been limited. A 40-year-old female patient presented with a space-occupying mass in the pancreas found by abdominal B-mode ultrasonography upon physical examination. Laparoscopic resection of the pancreatic body and tail was performed, and a cystic-solid tumor of about 2 × 2 cm was identified. PEComa is a type of mesenchymal tumor with uncertain biologic behavior, more frequently found in females. PEComa features a unique histomorphology and immunophenotype. We summarize the characteristics and research progress of the pancreatic PEComa, which will be convenient for physicians and pathologists to fully understand the disease to avoid misdiagnosis and to provide a reference for treatment and prognosis.

A rare case of spontaneous rupture of epithelioid angiomyolipoma

A male patient, 40 years of age, arrived at our Institute with diffuse abdominal tenderness, right flank pain, hematuria and early stage of hemorrhagic shock with anemia and initial hypotension. The immediate clinical history revealed no significant previous trauma, only subsequently was reported inconstant pain in the right flank for 4–5 days with pallor and asthenia, signs and symptoms that the patient had not investigated. Abdominal CT scan with angiographic evaluation was performed showing right kidney mass and perirenal fluid collection by blood component. Immediate nephrectomy was performed and histopathological and further immunohistochemical study, revealed the epithelioid variant of angiomyolipoma.

Malignant Perivascular Epitheloid Cell Tumor with an Unusual Immunophenotype in a Ten-Year-Old Child

Introduction: Perivascular epitheloid cell tumors (PEComa) represent a group of usually benign mesenchymal neoplasms. Malignant variants are usually found only in adults.Case: We present a 10-year-old girl with infraclavicular malignant PEComa, negative for HMB-45 and Melan A but focally positive for MITF.Conclusion: To the best of our knowledge, no malignant variant of PEComa has been described in soft tissue in a child. Generally, PEComas are immunoreactive for HMB-45 and/or Melan A while our case was negative for both. Further studies are necessary to elucidate the significance of this immunohistochemical finding.

Imaging appearance of renal epithelioid angiomyolipoma: A case report and literature review

RATIONALE

Epithelioid angiomyolipoma (EAML) is an extremely rare disease. It commonly occurs in middle-aged females and mainly involves the kidney. Histological and immunohistochemical examination play important roles in differentiating EAML from renal cell carcinoma (RCC) and poor-fat angiomyolipoma (AML).

PATIENT CONCERNS

Here, We report the imaging phenotype, as well as the pathological findings of a case of EAML in a 39-year-old female.

DIAGNOSES

Preoperative noncontrast computed tomography (CT) scan revealed a 6.0 × 5.2 × 7.0 cm soft tissue mass with necrosis, located in the left kidney. On contrast-enhanced CT images, aprogressive enhancement pattern was observed. CT angiography did not show any enlarged vessels or vascular malformation. Abdominal MRI showed a well-circumscribed solid mass with a heterogeneous signal on T1-weighted and T2-weighted images. Ultrasonography of the abdomen demonstrated a hypoechoic mass with abundant blood flow. This patient underwent radical nephrectomy. The pathologic diagnosis was EAML.

INTERVENTIONS

This patient underwent operative resection of the tumor. The resection margins were negative for the neoplastic proliferation and no distant metastases were found. The patient did not receive advanced radiotherapy or chemotherapy.

OUTCOMES

Four months after surgery, the follow-up CT scan did not reveal any local recurrence or distant metastases.

LESSONS

This case adds to the experience with EAML by summarizing its imaging characteristics as well as reviewing the literature. Additionally, we described the state-of-the-art management of the management of this rare tumor.

Malignant PEComa With Metastatic Disease at Diagnosis and Resistance to Several Chemotherapy Regimens and Targeted Therapy (m-TOR Inhibitor)

Perivascular epithelioid cell tumors (PEComas) are infrequent neoplasms with peculiar myomelanocytic differentiation. The aggressive abdominopelvic variant is rare, with only a small number of published cases. We present an additional case of this unusual variant, which showed an aggressive histologic and clinical behavior with multiple liver metastases and resistance to several therapies. We also discuss the histological and immunohistochemical profiles as well as the differential diagnosis.