Epithelioid lymphangioleiomyomatosis-like tumour of the uterus in a patient without tuberous sclerosis: a lesion mimicking epithelioid leiomyosarcoma

Systematic analysis of perivascular epithelioid cell neoplasms in the female reproductive tract: a comprehensive review

Perivascular epithelioid cell neoplasms (PEComas) are rare mesenchymal lesions, with gynecological PEComas accounting for just over a quarter of cases. Limited reports exist on gynecological PEComa, primarily treated with surgery; adjuvant therapy is considered in high-risk cases. This systematic review aims to summarize the origin and clinical, pathological and molecular characteristics of uterine PEComa, focusing on treatment options for gynecological PEComa. A comprehensive PubMed review of gynecological PEComa reports was conducted. A detailed examination of the literature ensured a thorough understanding. Gynecological PEComa diagnosis relies on histology and immunology. Despite therapy controversies, surgery remains the mainstay. Adjuvant therapy efficacy in high-risk cases is uncertain. mTOR inhibitors are the first line; alternative treatments, including angiogenesis and aromatase inhibitors, should be considered.

A Retrospective Case Study of 13 Uterine Perivascular Epithelioid Cell Neoplasm (PEComa) Patients

Introduction and Hypothesis

Perivascular epithelioid cell neoplasms (PEComas) are rare mesenchymal tumors that originate from perivascular epithelioid cells. The uterus is the second most common organ to be affected by PEComa. Most PEComas are benign and the prognosis is usually good. Surgery is the main treatment at present, and adjuvant therapy is mainly used for malignant cases. However, because of the lack of described cases, the best diagnosis and treatment of these tumors cannot be determined.

Methods

From 2009 to 2020, 13 patients from Shengjing Hospital (China Medical University), with uterine PEComa, who met the inclusion criteria and appropriate pathological diagnosis were enrolled in this study. Clinical, pathological, and therapeutic features were retrospectively analyzed to determine the best approach towards diagnosis and treatment.

Results

All the enrolled patients underwent surgical treatment; four of them had a malignant PEComa. Three of the malignant patients received chemotherapy after surgery; among them, one died, another showed no obvious recurrence after regular re-examination, and the third did not undergo any further treatment despite short-term recurrence. However, upon regular re-examination, no progress was observed. The fourth malignant patient did not receive chemotherapy after surgery and showed no obvious recurrence during regular reviews.

Conclusion

The preoperative diagnosis of uterine PEComa lacks specificity and therefore is often confused with uterine leiomyoma or leiomyosarcoma. We conclude that uterine PEComa can be diagnosed by combined analysis of immunohistochemistry and post-operative pathology. Though surgical resection is still the main treatment, high-risk patients can be given adjuvant treatment to strengthen disease control.

Perivascular Epithelioid Cell Tumor (Pecoma) in the Transverse Colon of an Adolescent: A Case Report

Perivascular epithelioid cell tumor (PEComa) is defined as a very rare mesenchymal tumor of histologically and immuno-histochemically distinctive perivascular epithelioid cells. PEComa in the colon is very rare, with only a few reported cases so far. Because of its rarity, the clinical features and biological behavior of PEComa in the colon have yet to be established. A 16-year-old female patient with PEComa in the transverse colon was referred to our hospital for rectal bleeding. Laboratory data showed a hemoglobin level of 6.6 g/dL, WBC of 8,800/mm3, and platelet count of 191,000/mm3. Colonoscopy, barium enema, and abdominal computed tomography revealed a 2-cm, smooth-surfaced, round tumor with focal ulceration in the proximal transverse colon. The patient complained of abdominal pain one day after endoscopic polypectomy. She underwent a segmental resection for a perforated transverse colon. Immunohistochemically, the tumor cells showed strong diffuse positivity for HMB-45 while they were negative for c-kit, smooth muscle actin, cytokeratin, S-100, vimentin, desmin, chromogranin, synaptophysin, EMA, and CD-34. The diagnosis of PEComa was based on histological and immunohistochemical staining. The patient did not receive any adjuvant therapy and was discharged on postoperative day 11 without complications. Whole-body fluorine-18 fluorodeoxyglucose fusion positron emission tomography performed 2 months after surgery showed no signs of recurrence or metastasis. There was also no recurrence or metastasis at 24 months' follow-up.

Predicting the Behavior of Perivascular Epithelioid Cell Tumors of the Uterine Corpus

Perivascular epithelioid cell tumors (PEComas) are rare neoplasms that share phenotypic features with angiomyolipomas, clear cell sugar tumors, and lymphangioleiomyomatosis. They presumably represent the neoplastic counterpart of a yet-unidentified perivascular epithelioid cell that expresses smooth muscle and melanocytic immunomarkers. The uterus is the second most common site of origin for perivascular epithelioid cell tumors, after the retroperitoneum. Although most uterine perivascular epithelioid cell tumors are clinically benign and can be cured by a complete surgical excision, there is a subset characterized by both local and distant dissemination. Unfortunately, no single histopathologic or immunohistochemical parameter can accurately predict the clinical behavior of these tumors, which is why the 2012 World Health Organization classification of tumors of the female reproductive organs suggests the use of several criteria to predict the risk of aggressive clinical behavior. Here we review those perivascular epithelioid cell tumors of the uterine corpus with aggressive clinical behavior reported in the literature, and we discuss their most relevant clinical and histopathologic features.

[A case of malignant perivascular epithelioid cell tumor of the retroperitoneum with multiple metastases]

Perivascular epithelioid cell tumors (PEComas) are unusual mesenchymal neoplasms composed of histologically and immunohistochemically distinct perivascular epithelioid cells (PECs). Although PEComas have the potential to behave in a malignant fashion, malignant PEComas arising from the retroperitoneum are extremely rare. A 68-year-old woman presented with a painful palpable mass in her left upper abdomen. Computed tomography of the abdomen showed a 9 cm sized heterogeneous mass in left para-aortic space and multiple hypervascular nodules in the liver. (18)F-fludeoxyglucose-PET/CT showed multifocal hyper-metabolic lesions in retroperitoneum, liver, and skeletal bones. Percutaneous needle biopsies were done on the retroperitoneal and hepatic mass. Both specimens were positive for human melanoma black-45 (HMB-45) on histological and immunohistochemical staining which was compatible with PEComas. Herein, we report a rare case of retroperitoneal PEComa with multiple metastases involving liver and bone at initial diagnosis that exhibited aggressive behavior and resulted in a devastating prognosis.

Perivascular epithelioid cell neoplasm (PEComa) of the uterus: A systematic review

BACKGROUND

Perivascular epithelioid cell neoplasm (PEComa) is a rare mesenchymal tumor. Gynecological PEComas account for just over one-fourth of the overall PEComa cases reported in the literature. Surgery is the most recommended primary treatment while adjuvant therapy is generally reserved for high-risk cases. However, the best management of this neoplasia has not been well established, primarily because of the paucity of cases described to date.

OBJECTIVES

The aim of this systematic review is to summarize what is known thus far regarding the etiopathogenesis, clinical and pathologic features of PEComas, focusing also on the most valid treatment options for uterine cases.

DATA SOURCES

Pubmed articles on PEComas published in various journals over the past 70 years were analyzed.

CONCLUSIONS AND KEY FINDINGS

Although the optimal treatment of gynecological PEComas is controversial, surgical resection remains the cornerstone. The use of adjuvant treatment is warranted in high risk patients to increase disease control. A multidisciplinary approach should be key in treatment decision-making regarding gynecological PEComas.

Perivascular epithelioid tumours (PEComas) of the gynaecological tract

Perivascular epithelioid tumours (PEComas) of the gynaecological tract are rare tumours which were first recognised and diagnosed within the last 20 years. They represent a unique diagnostic challenge with regard to their accurate and reproducible distinction from more common entities such as smooth muscle tumours of the uterine corpus. In this review article, we trace the development of the concept of the PEComa tumour family, highlight what is known about extra-gynaecological tract PEComa at an immunohistochemical, molecular and therapeutic level and then present a summary of all reported cases of gynaecological tract PEComa to date. In the summary, we highlight rare subtypes of gynaecological tract PEComa and compare the performances of extant prognostic classification systems for malignancy in these tumours.

Abdominal manifestations of neurologic disorders

A variety of disorders-including infectious, inflammatory, hereditary, and metabolic diseases-may affect both the brain and abdominal cavity, and the findings in one region may help establish the diagnosis or limit the differential diagnosis. Establishing an accurate early diagnosis enables clinicians to adequately manage these unusual diseases and potentially avert life-threatening complications. For example, an early diagnosis of Gardner syndrome enables annual sigmoid- or colonoscopy and ultrasonography. In many conditions, abdominal manifestations precede neurologic manifestations and may have prognostic significance. Patients with celiac disease more often present with abdominal manifestations such as duodenitis, slow transit time, reversal of the jejunal-ileal fold pattern, and transient small bowel intussusception than with intracranial manifestations. In other conditions, the neurologic manifestations may be the same as the presenting symptoms. For example, patients with Gardner syndrome may initially present with multiple mandibular or sinonasal osteomas. In addition, sarcoidosis may manifest with multifocal enhancing dural masses. Abdominal and neurologic manifestations may even occur simultaneously, as in several of the phakomatoses such as neurofibromatosis type 1, tuberous sclerosis complex, and von Hippel-Lindau syndrome. Ultimately, familiarity with the appearances of these conditions allows radiologists to pinpoint a diagnosis, even when imaging findings in either location are nonspecific.

Heterologous and rare homologous sarcomas of the uterine corpus: a clinicopathologic review

Pure sarcomas of the uterine corpus are uncommon, constituting less than 3% of all malignancies at this site, and most of them are leiomyosarcomas and endometrial stromal sarcomas. Rare histotypes of homologous sarcomas and heterologous sarcomas are occasionally encountered, and the absence of significant accumulated experience with these histotypes at this location may potentially raise diagnostic and patient management difficulties. In this article, the clinicopathologic attributes of all earlier reported sarcomas of the uterine corpus other than leiomyosarcomas and endometrial stromal sarcomas are summarized. Included are embryonal rhabdomyosarcoma, pleomorphic rhabdomyosarcoma, angiosarcoma, alveolar soft part sarcoma, malignant perivascular epithelioid cell tumors (PEComas), osteosarcoma, chondrosarcoma, liposarcomatous tumors, malignant extrarenal rhabdoid tumors, Ewing sarcoma/primitive neuroectodermal tumor, and other rare histotypes. Embryonal rhabdomyosarcoma (20%), Ewing sarcoma/primitive neuroectodermal tumor (17%), angiosarcoma (14%), and pleomorphic rhabdomyosarcoma (13%) appeared to be more common than the others, although there was no single overwhelmingly prevalent histotype in the group. A subset, including embryonal rhabdomyosarcoma, alveolar soft part sarcoma, and PEComas, peak in the premenopausal years, but most of the others were observed in postmenopausal women. Favorable outcomes have been reported for the patients diagnosed with alveolar soft part sarcoma, and the prognosis for their counterparts with PEComa remains a matter of debate. Multimodal therapeutic approaches to contemporary patients with embryonal rhabdomyosarcomas have resulted in significantly improved outcomes. Unfortunately, most of the other sarcomas have been associated with rapid tumor progression and unfavorable patient outcomes. The differential diagnosis for these sarcomas is often extensive and varies by histotype, but their accurate diagnosis fundamentally requires the careful exclusion of biphasic malignancies.

Perivascular epithelioid cell neoplasms: a systematic review of prognostic factors

Perivascular epithelioid cell tumors (PEComas) are rare, soft tissue tumors characterized by epithelioid cells with clear or eosinophilic cytoplasm and a perivascular disbursement. We compiled the treatment and follow-up results from an extensive collection of reported gynecologic PEComa cases and statistically analyzed their respective therapy modalities and corresponding patient outcomes. In the group of patients with PEComa who received surgical management alone, there was a tendency for them to exhibit a lower disease recurrence rate. Conversely, patients with PEComa who initially received surgery and chemotherapy or radiation therapy were associated with a higher disease recurrence rate (P =.024). Metastatic involvement was related to higher patient mortality rates (P =.0001), although this finding was unrelated to treatment type. Surgical management alone may suffice for nonaggressive lesions, but chemotherapy and radiotherapy appear necessary for patients who present with high-risk histologic condition or metastatic disease. Because PEComas exhibit varying biologic behavior and an ill-defined presentation, the treatment for these lesions necessitates further evaluation.

Acute abdomen as an unusual presentation of hepatic PEComa. A case report

Perivascular epithelioid cell (PEC) tumors (or PEComas) are myomelanocytic lesions defined by coexpression of melanocytic and muscle markers, suggesting dual differentiation. They are rare mesenchymal tumors and include subtypes with distinct clinical features: angiomyolipoma, lymphangioleiomyomatosis, and clear cell "sugar" tumors of the lung, pancreas and uterus. Consequent upon the World Health Organization's recognition of PEC-derived tumors as a distinct entity, an increasing number of reports has documented PEComas arising at various anatomical locations. Clear cell myomelanocytic tumors of the falciform ligament/ligamentum teres (CCMTs) represent a rare variant of the PEComas. These hepatic PEComas, different from angiomyolipoma of the liver, pose a clinical, radiological and morphological diagnostic challenge. Because of their rarity, the clinical features and biological behavior of these tumors have yet to be established. We experienced our first case of CCMT in a 36-year-old woman who presented to our emergency department with a 3-day history of abdominal discomfort and progressive growth of an epigastric bulk. Intralesional hemorrhage was causing abdominal distension, which progressed to acute abdomen soon after. The hemoglobin concentration was 9.9 g/dL. Liver laboratory tests showed slight elevation of AST, ALT and gamma-GT. The alpha-fetoprotein level was not elevated. The radiological images showed a hemorrhagic mass with some bizarre features in left hepatic lobe, immediately adjacent to the ligamentum teres and falciform ligament. The patient underwent a left hepatic lobectomy. The diagnosis of CCMT was based on histological and immunohistochemical staining. The postoperative course was uneventful. The patient received no adjuvant treatment and is currently, 34 months after surgery, alive and disease free. In this report we describe a peculiar and hitherto undescribed clinical presentation of this tumor and its further course. Moreover, we discuss previously undescribed diagnostic imaging. We recommend that all unusual carcinomas and mesenchymal tumors of the liver should be tested for HMB-45: when positive, there is a high likelihood of PEComa.

Perivascular epitheloid cell tumour (PEComa) of the retroperitoneum - a rare tumor with uncertain malignant behaviour: a case report

INTRODUCTION

Perivascular epitheloid cell tumours are rare mesenchymal neoplasms characterized by a proliferation of perivascular cells with an epitheloid phenotype and expression of myomelanocytic markers.

CASE PRESENTATION

Here we present the case of a cystic perivascular epitheloid cell tumour of the retroperitoneum associated with multifocal lung lesions. A 27-year-old woman underwent laparotomy to remove a 10 x 6 x 4 cm sized retroperitoneal mass. The resected specimen was subjected to frozen and permanent histological sections with conventional and immunohistochemical stains, including antibodies against HMB45. The tumour displayed the typical morphological and immunohistochemical features of a perivascular epitheloid cell tumour. Focal necrosis and a proliferative index of 10% suggested a malignant potential. Moreover, postoperative computed tomography scans demonstrated multiple lung lesions, which were radiologically interpreted as being most likely compatible with lymphangioleiomyomatosis.

CONCLUSION

Since lymphangioleiomyomatosis, an otherwise benign condition, belongs to the family of perivascular epitheloid cell tumours, it cannot be excluded that the lung lesions in this case in fact represent metastases from the retroperitoneal perivascular epitheloid cell tumour rather than independent neoplasms. More experience with this new and unusual tumour entity is clearly needed in order to define reliable criteria for benign or malignant behaviour.

Uterine perivascular epithelioid cell tumor coexisting with pulmonary lymphangioleiomyomatosis and renal angiomyolipoma: a case report

We present a case of uterine perivascular epithelioid cell tumor (PEComa) coexisting with both pulmonary lymphangioleiomyomatosis and renal angiomyolipoma. The patient was a 42-year-old woman, suffering from massive abnormal uterine bleeding, progressive dyspnea, and arterial hypertension. Her clinical history included diagnoses of bilateral renal angiomyolipoma and pulmonary lymphangioleiomyomatosis. The patient underwent a subtotal hysterectomy and the specimen contained a subserosal tumor with irregular outlines in addition to uterine leiomyomata. The uterine tumor was histologically composed of solid sheets and tonguelike infiltration and lymphangioleiomyomalike structures within the myometrium, formed by epithelioid cells with ovoid to round nuclei and clear to light eosinophilic cytoplasms. The tumor did not display any morphologic sign of malignancy. The tumor cells showed expression of HMB-45 and smooth muscle markers. Ultrastructural analysis revealed abundant cytoplasmic microfilaments and rare small cytoplasmic bodies with a gridlike lining. We conclude that identification of lymphangioleiomyomalike growth pattern may aid in the differential diagnosis of uterine PEComa and suggest using both PEComa and smooth muscle tumor terminology.

Pathology of uterine malignancies

This overview covers epithelial, stromal and mesenchymal malignancies of the body of the uterus, excluding the cervix. The distinction of type I and type II endometrial adenocarcinoma with the morphological variants of this tumour is discussed and some molecular aspects are explored. The concept of carcinosarcoma representing a metaplastic adenocarcinoma of the endometrium that behaves more like a carcinoma than a sarcoma is explained. Some types of mixed epithelial and stromal neoplasm are described and contrasted with carcinosarcoma. The concept of stromal sarcoma and high-grade uterine sarcoma is described and an outline of malignant smooth muscle tumours of the uterus includes a description of smooth muscle tumours of uncertain malignant potential and worrying benign smooth muscle lesions.

Multifocal PEComa (PEComatosis) of the Female Genital Tract Associated With Endometriosis, Diffuse Adenomyosis, and Endometrial Atypical Hyperplasia

The authors describe a case of multifocal perivascular epithelioid cell tumor (PEComa) arising in the pelvis of a 39-year-old woman affected by tuberous sclerosis. The tumor presented in the form of multiple fascicular, focally cystic nodules involving the uterine corpus, both ovaries, and the omentum. Microscopically, the nodules were composed of foci of adenomyosis and endometriosis (with focal atypical complex hyperplasia) associated with a stromal spindle cell population immunoreactive for HMB-45, smooth muscle actin, and estrogen and progesterone receptors. We interpret these foci as the result of a widespread proliferation of perivascular epithelioid cells (PEC). Because of the diffuse quality of the process, the designation of PEComatosis seems warranted.

Uterine PEComa: appraisal of a controversial and increasingly reported mesenchymal neoplasm

In recent years, a group of tumors that have been designated "perivascular epithelioid cell tumors" (PEComa) have been reported with increasing frequency from a wide variety of anatomic locations. The uterus and retroperitoneum appear to be the most frequent sites of origin for these lesions. PEComas belong to an identically named family of tumors comprised of conventional angiomyolipomas, clear cell sugar tumors, lymphangiomyomatosis and clear cell myomelanocytic tumor of the falciform ligament/ligament teres, and are also known as PEComa-NOS. This article is a primer for clinicians on the most salient clinicopathologic features of uterine PEComas, as most of the debate and discussion have taken place in the pathologic literature. The author appraises in detail the current state of knowledge on PEComas of the uterus based on a review of published data on the 44 previously reported cases, and comments on areas of controversy. The latter are centered predominantly on the significant morphologic and immunophenotypic overlap that exists between uterine PEComa and some smooth muscle tumors of the uterus. The clinicopathologic features of cases reported as epithelioid smooth muscle tumors and cases reported as uterine PEComas are compared and contrasted, and a practical approach to their reporting is proposed.

Perivascular epithelioid cell tumor (PEComa) of the uterus: an outcome-based clinicopathologic analysis of 41 reported cases

The uterus and retroperitoneum have emerged as the most frequently reported anatomic sites of origin of perivascular epithelioid cell tumors (PEComas), a poorly defined neoplasm that is characterized by varying amounts of spindle and epithelioid cells with clear to eosinophilic cytoplasm that display immunoreactivity for melanocytic markers, most frequently HMB-45. Published reports on 41 previously reported uterine PEComas are reviewed in this report. Of these 41 cases, 31 originating in the corpus and for which there was adequate follow-up information (or clinical malignancy) were categorized into 2 groups: (1) a malignant group that was comprised of cases associated with patient death of disease and/or clinical malignancy as evidenced by local and/or distant extension outside of the uterus (n=13, group 1) and (2) a "nonmalignant" group of cases in which neither of the above features were present (n=18, group 2). Groups 1 and 2 did not significantly differ regarding duration of follow-up (25 mo vs. 24.3 mo, respectively, P=0.9) or patient age (45.61 y vs. 43.46 y, respectively, P=0.7). Five of the group 1 patients experienced distant (extra-abdominal) metastases. The group 1 tumors were significantly larger than the group 2 tumors (averages 9.6 cm vs. 4.67 cm respectively, P=0.04); however, there were no size thresholds that, in of themselves, reliably classified 75% or more of the cases in both groups. Coagulative necrosis was highly associated with group 1, being present in 82% of cases as compared with only 11.8% of group 2 cases (P=0.0002). Eighty-eight percent of the group 2 cases had a mitotic rate of <or=1/10 high power fields (HPF) as compared with 40% of group 1 cases (P=0.01). However, the absence of mitotic activity did not rule out malignancy, as 2 of the group 1 cases lacked mitotic activity and displayed metastases. Twenty-five percent, 49%, 56%, 73%, and 100% of tested cases displayed immunoreactivity for CD10, desmin, vimentin, smooth muscle actin, and caldesmon, respectively. PEComas are tumors of uncertain histogenesis and malignant potential that seem to display some morphologic and immunophenotypic overlap with smooth muscle neoplasia. A mitotic count of >1/10 HPF and/or coagulative necrosis are features that, if present, raise the definite potential for aggressive behavior.

Malignant clear-cell myomelanocytic tumor of broad ligament--a case report

Clear-cell myomelanocytic tumors (CCMT) of the perivascular epithelioid cell tumor (PEComa) family have been recently reported. We report a case involving a 12-year-old girl. The tumor (9 x 7.5 x 7 cm) was a firm, tan-gray mass with heavily dark pigmentation, massive hemorrhage, and necrosis, and was located in the right broad ligament attached to the right ovary. Histologically, the tumor was composed of polygonal cells exhibiting diffuse hemorrhage, multifocal necroses, and vascular invasion. Most of the tumor cells contained melanin pigments with Fontana-Masson positivity and ultrastructurally suspicious, membrane-bound premelanosomes. Immunohistochemical staining was positive against HMB-45 and focally positive for smooth muscle actin. The tumor recurred in the form of multiple conglomerated masses of the right iliac fossa, with the greatest measuring up to 3.8 cm in dimension, within 1 year. Most CCMT are believed to originate from falciform ligament/ligamentum teres. To the best of our knowledge, this is the second report of a CCMT arising in the broad ligament with typical morphology and contributory ancillary results. Further study for proper subclassification of the PEComa family should be validated, not by anatomic site but by clinical behavior.

Perivascular epithelioid cell neoplasms of soft tissue and gynecologic origin: a clinicopathologic study of 26 cases and review of the literature

PEComas, occasionally associated with the tuberous sclerosis complex, are defined by the presence of perivascular epithelioid cells that coexpress muscle and melanocytic markers. This family of tumors includes angiomyolipoma (AML), clear cell sugar tumor of the lung (CCST), lymphangioleiomyomatosis (LAM), and very rare tumors in other locations. Because non-AML/non-LAM PEComas are extremely rare and their natural history and prognostic features undefined, we present our experience with 26 PEComas of soft tissue and the gynecologic tract, the largest series to date. We also performed a detailed review of the literature, with special attention to features predictive of clinical behavior. All PEComas exclusive of AML and LAM were retrieved from our consultation files. Immunohistochemistry for pan-cytokeratin (CK), S-100 protein, smooth muscle actins (SMA), desmin, vimentin, HMB45, Melan-A, microphthalmia transcription factor (MiTF), TFE3, CD117, and CD34 was performed. Clinical follow-up information was obtained. Fisher's exact test was performed. The median patient age was 46 years (range, 15-97 years); there was a marked female predominance (22 females, 4 males). Sites of involvement included the omentum or mesentery (6 cases), uterus (4 cases), pelvic soft tissues (3 cases), abdominal wall (2 cases), uterine cervix (2 cases), and vagina, retroperitoneum, thigh, falciform ligament, scalp, broad ligament, forearm, shoulder, and neck (1 case each). The tumors ranged from 1.6 to 29 cm in size (median, 7.8 cm). Tumors were epithelioid (N = 9), spindled (N = 7), or mixed (N = 10). Multinucleated giant cells were present in 18 cases. High nuclear grade was noted in 10 cases, high cellularity in 7 cases, necrosis in 8 cases, and vascular invasion in 3 cases. Mitotic activity was 0 to 50 mitotic figures (MF)/50 high power fields (HPF) (median, 0 MF/50 HPF) with atypical MF in 6 cases. IHC results were: SMA (20/25), desmin (8/22), HMB45 (22/24), Melan-A (13/18), MITF (9/18), S-100 protein (8/24), CK (3/23), vimentin (12/14), TFE3 (5/17), c-kit (1/20), and CD34 (0/7). Clinical follow-up (24 of 26 patients, 92%; median, 30 months; range, 10-84 months) showed 3 local recurrences and 5 distant metastases. At last available clinical follow-up, 2 patients (8%) were dead of disease, 4 patients (17%) were alive with metastatic or unresectable local disease, and 18 patients (75%) were alive with no evidence of disease. No patient in our series had a history of tuberous sclerosis complex. Recurrence and/or metastasis was strongly associated tumor size > median size (8 cm), mitotic activity greater than 1/50 HPF, and necrosis. We conclude that PEComas of soft tissue and gynecologic origin may be classified as "benign," "of uncertain malignant potential," or "malignant." Small PEComas without any worrisome histologic features are most likely benign. PEComas with nuclear pleomorphism alone ("symplastic") and large PEComas without other worrisome features have uncertain malignant potential. PEComas with two or more worrisome histologic features should be considered malignant. Occasional PEComas express unusual markers, such as S-100 protein, desmin, and rarely CK. The role of TFE3 in PEComas should be further studied.

Perivascular Epithelioid Cell Tumor of the Uterus: Report of Four Cases

Uterine perivascular epithelioid cell tumor (PEComa) is very rare, and there have been only 27 reported cases. The differentiation of the tumor has been enigmatic, and the biologic behavior remains unclear. This study describes the clinical, histologic, and immunohistochemical features of four cases of uterine PEComa. The patients were 30, 32, 36, and 40 years old, and none of them had tuberous sclerosis complex. The size of the tumors ranged from 1 to 30 cm in diameter, and 3 of the 4 tumors were confined in the uterus. One tumor involved the left ovary and omentum. Microscopically, the tumors were characterized by an epithelioid arrangement of tumor cells, which had abundant clear to eosinophilic pale granular cytoplasm, and one tumor had moderately atypical nuclei. Coagulative necrosis was found in two cases. The mitotic figures ranged from 0 to 11 per 10 high power fields. Immunohistochemically, the tumors were positive for vimentin (4/4), HMB45 (4/4), h-caldesmon (4/4), alpha-smooth muscle actin (3/4), muscle actin (2/4), and desmin (3/4). They were uniformly negative for Melan A, CD10, and S-100 protein. Ultrastructural examinations were performed on one case and revealed no melanosomes, premelanosomes, or evidence of smooth muscle differentiation. One patient died of intestinal metastases 17 months after surgery. The other patients have been well with no evidence of disease 8, 12, and 36 months after surgery. Uterine PEComa should be regarded as tumors with an uncertain malignant potential until long-term outcome data for a larger number of patients become available.

Perivascular epithelioid cell (PEC) tumors of the uterus: a clinicopathologic study of two cases with aggressive features

We report the clinicopathologic, immunohistochemical and ultrastructural features of two unusual tumors of the uterus composed of spindle and epithelioid cells strongly positive for HMB45. The two patients of 56 and 48 years of age had, respectively, hemoperitoneum and abnormal uterine bleeding. Morphologically, both tumors showed atypia and extensive necrosis. The neoplastic cells express immunohistochemically both melanogenesis (HMB45) and smooth muscle markers (actin). Ultrastructural analysis showed the presence of intracytoplasmic membrane-bound granules. We viewed these neoplasms as perivascular epithelioid cell (PEC) tumors with aggressive features. Follow-up has shown the death of one patient whereas the other is alive without disease 36 months after the surgery. The two patients were evaluated for signs of tuberous sclerosis complex, and findings were negative.

Malignant perivascular epithelioid cell tumour ("PEComa") of soft tissue: a unique case

Tumours of perivascular epithelioid cells (PEComas) are being increasingly reported at visceral and somatic sites. Both benign and malignant variants have been identified, although clinical follow-up is often limited, which prevents meaningful predictions of behavior. We report the case of a malignant soft tissue PEComa with histologically confirmed regional lymph node metastases and radiologically confirmed pulmonary metastases. The light microscopic appearance and immunohistochemical profile (HMB-45, smooth muscle actin positive) and electron microscopic appearance support perivascular epithelioid cell differentiation.

Malignant perivascular epithelioid cell tumor (PEComa) arising in the broad ligament

Malignant perivascular epithelioid cell tumor (PEComa) is an extremely rare mesenchymal neoplasm mostly composed of HMB-45-positive epithelioid cells with clear-to-eosinophilic cytoplasm, a propensity for perivascular distribution and a coexpression of smooth muscle markers. The uterus seems to be one of the most prevalent sites of involvement, although only 14 cases of uterine PEComa have been described. We report the case of a 51-year-old woman with a PEComa arising in the broad ligament. She was treated with total abdominal hysterectomy, bilateral salpingo-oophorectomy, omentectomy, and pelvic radiation, and remains without evidence of disease 15 months after diagnosis. This is, to the best of our knowledge, the first report of a malignant PEComa arising in the broad ligament. To correctly diagnose PEComa, an extensive immunohistochemical panel is essential. As PEComas can behave in an aggressive manner, careful follow-up is warranted.

Malignant PEComa of the skull base

Perivascular epithelioid cell tumors (PEComas) are rare, usually benign lesions comprising a family of neoplasms including angiomyolipoma, lymphangioleiomyomatosis, clear cell "sugar" tumors, and clear cell myomelanocytic tumors. This report describes an apparent case of a malignant PEComa of the skull base in a 49-year-old woman, a previously undescribed location for this lesion.

Perivascular epithelioid cell tumor (PEComa) of the uterine cervix associated with intraabdominal "PEComatosis": A clinicopathological study with comparative genomic hybridization analysis

Background

The World Health Organization recently recognized a family of neoplasms showing at least partial morphological or immunohistochemical evidence of a putative perivascular epithelioid cell (PEC) differentiation. These tumors include angiomyolipoma (AML), clear cell "sugar" tumors of the lung (CCST), lymphangioleiomyomatosis (LAM), clear cell myomelanocytic tumors of the falciform ligament and distinctive clear cell tumors at various other anatomic sites.

Case presentation & methods

A 41-year old gravida-1 para-1 with tuberous sclerosis presented with an incidentally identified 2.2 cm mass. The morphology and immunohistochemical profile was consistent with PEComa. Distinct aggregates of HMB-45 epithelioid cells were present in an occasionally distinctive perivascular distribution in the myometrium, small bowel lamina propria and ovarian hila. These distinctive aggregates, for which we propose the designation "PEComatosis" based on their intraabdominal distribution, did not display cytological atypia, mitotic activity or necrosis. CGH and DNA ploidy analysis showed a balanced chromosomal profile and diploid nuclei, respectively. There was no recurrence or metastases at 35 months' follow-up. Fifty-one previously reported cases of non-AML, LAM and CCST PEComas [perivascular epithelioid cell tumors- not otherwise specified (PEComa-NOS)] are reviewed.

Conclusions

The lesions may be a reflection of tumor multicentricity, in which each may be a potential nidus for the development of future more well-developed tumors. Alternatively, they may be a manifestation of a poorly understood "field effect", in which there is an increased propensity to develop tumors of this type throughout the abdomen. Finally, and least likely in our opinion, they may represent tumor spread from its primary site.

Perivascular Epithelioid Cell Tumor of the Uterus: A Case Report

A case of perivascular epithelioid cell tumor (PEComa) arising in the subserosa of the uterus of a 32-year old woman is presented. The lesion, removed by local excision, was an unencapsulated rubbery mass 5.0 cm in diameter. The tumor was composed of round to polygonal cells with round nuclei and abundant clear to slightly eosinophilic cytoplasm containing glycogen, and the cells were arranged in short fascicles focally in a perivascular location. There were scattered foci of necrosis and hemorrhage. The tumor cells showed mild atypia and low mitotic activity, and they were strongly immunoreactive for vimentin, h-caldesmon, and HMB45. Ultrastructural examination showed no melanosomes or premelanosomes. The patient had no evidence of disease 8 months postoperatively. Uterine PEComas should be regarded as tumors with an uncertain malignant potential.

Uterine epithelioid leiomyosarcomas with clear cells: reactivity with HMB-45 and the concept of PEComa

In this study, we investigated HMB-45 expression in epithelioid uterine leiomyosarcomas with clear cell areas. From 12 epithelioid leiomyosarcomas, we selected 5 that had: 1) clear cell areas and 2) spindle cell areas that were at least focally positive for desmin and caldesmon. The patients' ages ranged from 47 to 82 years (mean 64 years). Presenting symptoms were uterine bleeding (three), abdominal pain (one), and a pelvic mass (one). There was no history of tuberous sclerosis or lymphangioleiomyomatosis. One patient had stage II disease, one stage III, and three stage IV. All were treated with total abdominal hysterectomy and bilateral salpingo-oophorectomy. Two received radiotherapy, and three were also treated with chemotherapy. The tumors ranged in size from 4 x 3 x 3 cm to 10 x 7 x 6 cm; all had significant cellular atypia, areas of coagulative necrosis, and between 10 and 90 mitoses per 10 high power fields. Vascular invasion was seen in three cases. The epithelioid component varied from 50% to 90% in each case; and the percentage of clear cells was < 1% in one case, 5% in one case, and 10% to 80% in three cases. Smooth muscle actin and desmin were positive in all cases. Four cases were positive for HMB-45 only in the clear cell areas. The tumor with < 1% of clear cells was negative for HMB-45. All were negative for S-100 and c-kit. Three patients died of disease at 9, 30, and 32 months; one patient is alive with progressive disease at 6 months, and one patient (stage II disease) is alive with no evidence of disease at 8 months. Unequivocal uterine epithelioid leiomyosarcomas may have clear cells positive for HMB-45. These tumors might belong to the group of lesion designated as PEComas; however, it is advisable to designate them as uterine leiomyosarcomas. In uterine smooth muscle tumors, some epithelioid cells most likely undergo clear cell changes and become positive for HMB-45. It would be advisable to perform this stain in all epithelioid smooth muscle tumors of the uterus.

Recurrent perivascular epithelioid cell tumor of the uterus (PEComa): an immunohistochemical study and review of the literature

BACKGROUND

Neoplasms of the perivascular epithelioid cell, first described in 1992, comprise a family of tumors known as "PEComas." To the best of our knowledge, this is the third case of uterine PEComa reported in the literature to behave in a malignant fashion. The purpose of this report is to provide information that may be used to predict the future behavior of this tumor.

CASE

The patient was a 79-year-old woman with a large uterine mass which recurred 2 years following resection. The patient died within months after resection of the recurrent tumor. Retrospective immunohistochemical staining with newly commercially available antibodies including MART-1 was done on both the original and the recurrent tumor, confirming the diagnosis of uterine PEComa.

CONCLUSION

Uterine PEComas should be regarded as tumors with uncertain malignant potential.

Late pulmonary metastasis in uterine PEComa

Perivascular epithelioid cell tumours (PEComas) other than angiomyolipoma, clear cell "sugar" tumour of the lung, and lymphangioleiomyomatosis are very rare mesenchymal tumours. The uterus seems to be the most prevalent site of involvement, but only 13 cases of uterine PEComa have been described. Three of these cases exhibited local aggressive behaviour and only one showed metastasis. Because of the extremely small number of cases, PEComas are considered tumours of uncertain malignant potential. This report describes a 68 year old woman, who presented with multiple pulmonary lesions seven years after the initial diagnosis of well differentiated endometrial stromal sarcoma. Histological and immunohistochemical analysis of the pulmonary lesions, in addition to re-evaluation of the primary uterine tumour, led to the final diagnosis of metastatic uterine PEComa. The findings indicate that any PEComa might have malignant potential. Spreading of this tumour to other organs might become evident even several years after primary manifestation.

Clear cell myomelanocytic tumor of the thigh: report of a unique case

The clear cell myomelanocytic tumor (CCMMT) is a recently reported and very rare member of the perivascular epithelioid cell family of tumors (PEComa). All CCMMTs reported to date have occurred in or immediately adjacent to the falciform ligament/ligamentum teres. We report a case of CCMMT that occurred in the right thigh of a 43-year-old woman. Histologic examination showed the classic features of CCMMT, and immunohistochemical studies confirmed co-expression of smooth muscle actin, HMB-45, and microphthalmia transcription factor.

Expression of KIT (CD117) in angiomyolipoma

Angiomyolipoma is a unique mesenchymal tumor postulated to arise from perivascular epithelioid cells. Immunohistochemical studies have shown that angiomyolipomas express the melanocytic markers HMB-45, MART-1 (Melan A), microphthalmia transcription factor, and tyrosinase, in addition to smooth muscle actin. KIT (CD117) is a transmembrane growth factor receptor expressed in cells of melanocytic and a variety of other cell lineages. To date, KIT immunoreactivity has not been systematically studied in angiomyolipoma. In this study we immunohistochemically analyzed a series of 21 angiomyolipomas (15 hepatic, six renal) with KIT. All were KIT positive: 14 of 21 (67%) with 3+ staining (>50% of tumor cells), 4 of 21 (19%) with 2+ staining (25-50% of tumor cells), and 3 of 21 (14%) with 1+ staining (<25% of tumor cells). In comparison, the percent of angiomyolipomas showing 3+ staining with HMB-45 was 62% and with Melan A was 52%. Positive KIT staining was detected in the epithelioid, spindle, and intermediate small round cells. Most cases showed diffuse cytoplasmic positivity. Strong perinuclear staining was present in the vacuolated clear epithelioid cells. There was focal KIT staining of fat cells. KIT was not detected in the endothelial cells lining blood vessels within the tumor. KIT may be a useful ancillary marker for the diagnosis of angiomyolipoma. Angiomyolipoma should be included in the differential diagnosis of KIT-positive tumors.

Perivascular epithelioid cell tumor ('PEComa') of the uterus: a subset of HMB-45-positive epithelioid mesenchymal neoplasms with an uncertain relationship to pure smooth muscle tumors

The family of lesions thought to be composed at least in part of perivascular epithelioid cells, characterized as HMB-45-positive epithelioid cells with clear to eosinophilic granular cytoplasm and a propensity for a perivascular distribution, includes some forms of angiomyolipoma and lymphangioleiomyomatosis, as well as clear cell "sugar" tumor (CC-SUGAR). When composed predominantly or exclusively of epithelioid cells, it has been suggested that these lesions be classified as "perivascular epithelioid cell tumors" (PEComa). Four cases of uterine PEComa have been described in the literature, three of which exhibited aggressive behavior. We report the clinical, histologic, and immunohistochemical features of eight more examples of uterine PEComa. Patients ranged in age from 40 to 75 years (mean 54 years). Most patients presented because of abnormal uterine bleeding, and grossly a mass was present in the uterine corpus. Morphologically, the tumors could be divided into two groups (A and B). Group A tumors demonstrated a tongue-like growth pattern similar to that seen in low-grade endometrial stromal sarcoma and were composed of cells that tended to have abundant clear to eosinophilic pale granular cytoplasm, diffuse HMB-45 expression, and focal muscle marker expression. Group B tumors were composed of epithelioid cells with less prominent clear cell features, smaller numbers of which were HMB-45-positive. They also featured extensive muscle marker expression and a lesser degree of the endometrial stromal sarcoma growth pattern seen in group A tumors. Two of the four patients with group B tumors had pelvic lymph nodes involved by lymphangioleiomyomatosis, and one of these patients had the tuberous sclerosis complex. Seven of the eight patients with PEComas were treated by hysterectomy. All eight patients are alive and well, although follow-up of >2 years was available only for two patients. Uterine epithelioid smooth muscle tumors and low-grade endometrial stromal sarcomas were compared with the PEComas. Group A PEComas, group B PEComas, and epithelioid smooth muscle tumors were all parts of a continuous histologic spectrum, with group A PEComa at one end of the spectrum and epithelioid smooth muscle tumors at the other, while group B tumors shared features of both. PEComa was histologically and immunohistochemically distinct from endometrial stromal sarcoma. Our data and a review of the literature indicate that PEComa is a subset of HMB-45-positive epithelioid mesenchymal tumors of the uterus with an uncertain relationship to pure smooth muscle tumors. Although none of the patients in this study experienced recurrence during a short follow-up period, some reported in the literature have had recurrences; consequently, we think uterine PEComa should be considered a tumor of uncertain malignant potential until long-term outcome data for a larger number of patients become available.

Abdominopelvic sarcoma of perivascular epithelioid cells. Report of four cases in young women, one with tuberous sclerosis

The perivascular epithelioid cell has been proposed to be the unifying proliferating cell type in a number of lesions such as angiomyolipoma, lymphangiomyomatosis, clear cell "sugar" tumor and renal capsuloma. With the exception of rare examples of angiomyolipoma, they are non-metastasizing. We report four examples of a new member of this family of perivascular epithelioid cell neoplasms that occur in abdominopelvic location and show metastatic properties. The patients, all women, were aged 19 to 41 years (mean, 32), and presented with a tumor mass involving the serosa of the ileum, uterus or pelvic cavity. Morphologically, the tumors were composed of sheets of large polygonal cells with glycogen-rich clear or eosinophilic cytoplasm and moderately pleomorphic nuclei, traversed by a delicate vasculature, mimicking clear cell carcinoma. There were areas of coagulative necrosis and occasional mitotic figures. Intracytoplasmic brown pigment was present in two cases. Spindly cells, smooth muscle and fat were absent. Lymphovascular invasion was present in all, lymph node metastasis was documented in two and metastasis to the ovary was present in one case. Two patients developed widespread metastatic disease after 10 and 28 months from diagnosis. One patient showed the clinical signs of tuberous sclerosis. In spite of the epithelial-like appearance, the tumor cells were negative for epithelial markers but were strongly positive with the melanogenesis-related marker HMB45. Another melanogenesis marker (MART-1) was positive in two cases. Other markers including S-100 protein, vimentin, muscle-specific actin, desmin and chromogranin A were negative. Thus, these tumors are not readily classifiable in the existing schema of known entities, and show overlapping morpho-phenotypic features of clear cell "sugar" tumor of the lung and epithelioid angiomyolipoma. We consider them as sarcomas composed of a pure population of uncommitted perivascular epithelioid cell, that lack modulation toward smooth muscle or adipose cells.

Immunohistochemical study of microphthalmia transcription factor and tyrosinase in angiomyolipoma of the kidney, renal cell carcinoma, and renal and retroperitoneal sarcomas: comparative evaluation with traditional diagnostic markers

Angiomyolipoma has a unique immunophenotype with co-expression of muscle-specific actin and melanocytic markers such as HMB-45 and Melan-A. The most recently developed melanocytic markers, microphthalmia transcription factor and tyrosinase, have not been studied in the diagnosis of angiomyolipoma. We tested 29 renal angiomyolipomas (21 classic histology, 4 epithelioid variants, 2 lipomatous variants, and 2 leiomyomatous variants) with an immunohistochemical panel, including microphthalmia transcription factor, tyrosinase, HMB-45, Melan-A, and muscle-specific actin. Results were compared with 15 renal cell carcinomas (9 conventional types, 6 with sarcomatoid change), 2 leiomyosarcomas, 5 liposarcomas, and 1 unclassified high-grade sarcoma. Microphthalmia transcription factor expression was seen in 22 of 29 angiomyolipomas, one renal cell carcinoma, and one well-differentiated liposarcoma (that is, 2 of 23 non-angiomyolipomas; sensitivity 75%, specificity 91%). Tyrosinase expression was seen in 4 of 29 angiomyolipomas and 0 of 23 non-angiomyolipomas (sensitivity 14%, specificity 100%). HMB-45 was positive in 24 of 29 angiomyolipomas and 0 of 23 non-angiomyolipomas (sensitivity 83%, specificity 100%). Melan-A was expressed by 25 of 29 angiomyolipomas and 0 of 23 non-angiomyolipomas (sensitivity 86%, specificity 100%). Muscle-specific actin was expressed by 29 of 29 angiomyolipomas and 2 of 23 non-angiomyolipomas (both leiomyosarcomas; sensitivity 100%, specificity 91% [100% excluding leiomyosarcomas]). Microphthalmia transcription factor showed the most widespread staining in angiomyolipoma (50% of cases staining more than half of the tumor cells) followed by Melan-A (24% of cases staining more than 50%). Only three cases showed positivity for all four melanocytic markers, while in one case each only microphthalmia transcription factor and Melan-A were positive. We conclude that microphthalmia transcription factor, but not tyrosinase immunostaining, has a sensitivity and specificity that rivals those of the established markers, HMB-45 and Melan-A, in the diagnosis of angiomyolipoma. Our data supports the use of a panel in difficult cases that includes antibodies to microphthalmia transcription factor, either Melan-A or HMB-45, and muscle-specific actin to provide the best mix of high sensitivity, high specificity, nuclear and cytoplasmic immunolocalization, and widespread staining of cells within a given tumor.

Hyalinized Uterine Mesenchymal Neoplasms with HMB-45-Positive Epithelioid Cells: Epithelioid Leiomyomas or Angiomyolipomas? Report of Four Cases

We present 4 cases of uterine mesenchymal tumors that were located mostly in the myometrium in middle-aged women. Grossly the tumors vaguely resembled conventional leiomyomas. All tumors were extremely hyalinized. The tumor cells were remarkable because of their large size and epithelioid shape. They occurred singly or more often in variously sized clusters with pericellular clear spaces looking like a halo. The extracellular matrix often formed lacunae around the neoplastic cells. The lacunar type of growth was somewhat reminiscent of immature cartilage. In some places the cells lined up in vague cord-like structures. The epithelioid cells often grew within vessel walls and subendothelially, simulating angioinvasion. In 2 cases there were periodic acid-Schiff (PAS)-positive, needle-shaped crystalloids in the cytoplasm of the tumor cells. No atypias and no mitoses were found in any of the 4 tumors. Mucicarmine stain was negative in all cases. Immunohistochemically the tumor cells were negative for cytokeratins, synaptophysin, chromogranin, epithelial membrane antigen (EMA) S-100 protein, and inhibin. They were instead strongly positive for smooth muscle actin, desmin and HMB-45. All patients are disease free after a 1-4-year follow-up. Int J Surg Pathol 8(4):323-328, 2000

Clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres: a novel member of the perivascular epithelioid clear cell family of tumors with a predilection for children and young adults

The perivascular epithelioid cell family of tumors (PEComas), defined by their co-expression of melanocytic and muscle markers, includes angiomyolipoma, lymphangioleiomyoma, and clear cell "sugar" tumors of the lung, pancreas, and uterus. We present seven cases of a unique and previously unrecognized tumor of children and young adults, which represents a new addition to the PEComa group of tumors. Culled from three institutions over a 50-year period, all cases occurred in or immediately adjacent to the ligamentum teres and falciform ligament. Six patients were female and one male; their ages ranged from 3 to 21 years (median, 11 yrs). Tumor sizes ranged from 5 to 20 cm (median, 8 cm). All cases consisted of clear to faintly eosinophilic spindled cells arranged in fascicular and nested patterns. The cells had small but distinct nucleoli and low mitotic activity. Immunohistochemically, all cases were positive with antibodies to gp100 protein (HMB-45) and negative for S-100 protein. In three of the seven cases studied immunohistochemically, the tumors expressed smooth muscle actin, melan-A, microphthalmia transcription factor (MiTF), and myosin, but not desmin. No expression of the TSC2 gene product, tuberin, was seen in three cases. One case studied cytogenetically disclosed a t(3;10). Follow-up data, available in six of seven cases (median duration, 18 mos), showed five patients to be free of disease and one to have a radiographically presumed lung metastasis. We think these tumors comprise a new entity for which we propose the term "clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres." The differential diagnosis of these tumors includes clear cell sarcoma of tendons and aponeuroses, leiomyosarcoma, and angiomyolipoma.

Giant abdominopelvic epithelioid angiomyolipoma associated with tuberous sclerosis: report of a case

Tuberous sclerosis is a hereditary autosomal-dominant disease characterized by hamartomas that can develop in any organ. We report herein the case of a 34-year-old female with tuberous sclerosis and a huge abdominopelvic mass that started growing quickly 2 years after its diagnosis. The patient had undergone several previous operations for hydrocephalus and cerebral tubers, and a nephrectomy for right renal angiomyolipoma. On admission, she was in poor general health with renal failure, severe anemia, and weight loss. A laparotomy revealed that the tumor occupied the pelvis, the lower and part of the upper abdomen, and was hypervascularized, with an extremely irregular surface covered in nodules, vegetations, and areas of hemorrhagic necrosis. The development of the mass and the impossibility of recognizing the internal genital organs led us to assume that the formation had originated from these. Frozen-section examination indicated an undifferentiated tumor that had not been completely resected. Her postoperative course was complicated by bronchopneumonia and progressive renal failure. The patient died 10 days after surgery due to cardiorespiratory failure. A histological diagnosis of epithelioid angiomyolipoma was confirmed. Although it is presently impossible to determine whether angiomyolipoma with predominant epithelioid cells is more aggressive than typical angiomyolipoma, it definitively demonstrated local aggressive behavior in this patient.