Malignant Perivascular Epithelioid Cell Tumor (PEComa) of the Adrenal Gland: Report of a Rare Case Posing Diagnostic Challenge with the Role of Immunohistochemistry in the Diagnosis

PEComa of the Adrenal Gland: A Clinicopathologic Series of 7 Cases

PEComas are a family of mesenchymal neoplasms composed of histologically distinctive perivascular epithelioid cells which demonstrate myomelanocytic differentiation. PEComas of the adrenal gland are very rare and can represent a considerable diagnostic challenge given their morphologic overlap with more common adrenal cortical neoplasms. We present the clinicopathologic features of 7 primary adrenal PEComas. The cohort comprised 5 male and 2 female patients with a median age of 63 years (range: 31 to 71 y). One patient had Birt-Hogg-Dubé syndrome and another had Lynch syndrome; however, none had a history of tuberous sclerosis complex. Histologically, tumors showed nested and/or sheet-like growth and epithelioid cytomorphology with pale-to-eosinophilic granular cytoplasm. Two tumors had an admixed spindle cell component. There was a median of 4 mitoses per 10 HPFs (range: 0 to 8). Necrosis was present in 4 tumors and lymphovascular invasion in 1. Four tumors were classified as malignant. By immunohistochemistry, tumors were positive for HMB-45 (3/7), MITF (3/3), Melan-A (3/7), smooth muscle actin (5/7), desmin (5/7), and caldesmon (1/1). Two tumors were positive for TFE3 (2/4). Inhibin and SF1 were negative in all tumors assessed (0/6). Of 3 patients with available clinical follow-up information, 1 patient developed locally recurrent and metastatic disease (at 18 mo) and was alive with persistent disease at the last follow-up. Two patients had no recurrent or metastatic disease at the last follow-up (60 and 25 mo). Although PEComas of the adrenal gland are rare, pathologists need to be alert to this entity in the differential diagnosis of primary adrenocortical neoplasms. In suspected cases, the judicious use of melanocytic and smooth muscle markers, in addition to TFE3 and markers of adrenocortical differentiation (such as SF1 and inhibin) can assist in diagnosis. As in PEComas arising at other visceral sites, an association with tuberous sclerosis complex seems to be uncommon.

Surprising genetic and pathological findings in a patient with giant bilateral periadrenal tumours: PEComas and mutations of PTCH1 in Gorlin-Goltz syndrome

Gorlin-Goltz syndrome (GGS) or nevoid basal cell carcinoma syndrome is a rare tumour-overgrowth syndrome associated with multiple developmental anomalies and a wide variety of tumours. Here, we describe a case of a man aged 23 years with GGS with bilateral giant tumours adjacent to both adrenals that raised the suspicion of malignancy on imaging. Histological analysis of both surgically resected tumours revealed perivascular epitheloid cell tumours (PEComas) that were independent of the adrenals. Exome sequencing of the patient’s blood sample revealed a novel germline heterozygous frameshift mutation in the PTCH1 gene. As a second hit, a somatic five nucleotide long deletion in the PTCH1 gene was demonstrated in the tumour DNA of both PEComas. To the best of our knowledge, this is the first report on PEComa in GGS, and this finding also raises the potential relevance of PTCH1 mutations and altered sonic hedgehog signalling in PEComa pathogenesis. The presence of the same somatic mutation in the bilateral tumours might indicate the possibility of a postzygotic somatic mutation that along with the germline mutation of the same gene could represent an intriguing genetic phenomenon (type 2 segmental mosaicism).

A Primary Adrenal Epithelioid Angiomyolipoma (PEComa) in a Patient with Tuberous Sclerosis Complex: Report of a Case and Review of the Literature

Epithelioid angiomyolipomas (EAMLs) are mesenchymal tumors that are part of the family of the perivascular epithelioid cell neoplasms (PEComas). These tumors portray a potential aggressive behavior with metastatic lesions found in around 30% of reported cases. EAMLs might present sporadically or in association with the tuberous sclerosis complex (TSC). They typically involve the kidneys, liver, and lungs. It is extremely rare for these tumors to arise from other organs. The present report describes an unusual case of an adult patient with a history of TSC who developed EAML of the adrenal gland. Moreover, he presented with metastatic disease to the liver, a feature rarely described. The diagnosis of EAMLs can be challenging as they are hard to distinguish from other adrenal or renal tumors without a thorough histopathologic and immunohistochemical evaluation. Due to the potential aggressive behavior of these malignancies, timely diagnosis is extremely important and has significant therapeutic and prognostic implications.

Immunohistochemical Biomarkers of Mesenchymal Neoplasms in Endocrine Organs: Diagnostic Pitfalls and Recent Discoveries

Mesenchymal neoplasms rarely present in or adjacent to endocrine organs. In this context, the recognition of these rare tumor types can be challenging, with significant potential for misdiagnosis as sarcomatoid carcinomas (i.e., anaplastic thyroid carcinoma and sarcomatoid adrenal cortical carcinoma) or neuroendocrine carcinomas, depending upon the dominant histologic patterns. In this review, we address potential pitfalls in diagnosing selected mesenchymal neoplasms arising within or near endocrine organs, including dedifferentiated liposarcoma, synovial sarcoma, angiosarcoma, PEComa, proximal-type epithelioid sarcoma, Ewing sarcoma, and neuroblastoma. For each of these tumor types, we review clinical and pathologic features, histologic clues to distinguish them from endocrine neoplasms, and recently developed immunohistochemical markers that can be particularly useful for establishing the correct diagnosis.

The Pathologic Point of View of Laparoscopic Adrenalectomy in the Era of Radiologic Imaging: A Multicenter Retrospective Study

INTRODUCTION/AIM

This study aimed to determine if laparoscopic adrenalectomy (LA) is feasible for the treatment of adrenal malignancies and metastasis, and to review the final pathology findings in order to clarify the indications for surgery.

MATERIALS AND METHOD

The medical records of all patients that underwent LA at 3 university hospitals between January 1, 2008, and May 1, 2015, were retrospectively reviewed.

RESULTS

In total, 189 laparoscopic adrenalectomies were completed successfully. Mean duration of surgery was 79.3 ± 38.6 min and mean estimated intraoperative blood loss was 39.9 ml. Intraoperatively, 4 patients had major complications: spleen injury (n = 1), renal vein injury (n = 2) and diaphragm injury (n = 2). Histopathological examination showed that there were 20 different types of lesions. Surgical margins (SMs) were tumor free in 95.2% of the patients. Moreover, SMs were tumor free in all patients with adrenocortical carcinomas; however, positive margins were noted in 7 of 23 patients (30.4%) with malignant adrenal tumors.

CONCLUSIONS

The present findings support the use of laparoscopy for metastatic adrenal masses, despite a high positive margin rate. LA is a safe, feasible and cost-effective procedure for the management of benign and malignant adrenal masses.