"Malignant" Uterine Perivascular Epithelioid Cell Tumor, Pelvic Lymph Node Lymphangioleiomyomatosis, and Gynecological Pecomatosis in a Patient With Tuberous Sclerosis: A Case Report and Review of the Literature

Uterine PEComatosis With TSC1 Mutation in a Patient With Tuberous Sclerosis: Case Report and Literature Review

Uterine PEComatosis is a rare phenomenon characterized by the presence of multiple perivascular epithelioid cell tumors (PEComas) and/or microscopic proliferations of perivascular epithelioid cells. Herein, we report a case of PEComatosis arising in a 49-yr-old woman with a known history of tuberous sclerosis. Targeted next-generation sequencing revealed a TSC1 stopgain mutation (p.Q732X) in all tested nodules, with single-copy TSC1 loss or copy-neutral TSC1 loss of heterozygosity. To our knowledge, this is the second report of TSC1 inactivation in uterine PEComa and the first report of confirmed TSC1 abnormalities in PEComatosis.

Update on Uterine Mesenchymal Neoplasms

This review focuses on recent advances in epithelioid and myxoid uterine mesenchymal neoplasms, a category of tumors whereby diagnostic criteria have been rapidly evolving due to advances in molecular testing. Pertinent clinicopathological and molecular features are highlighted for perivascular epithelioid cell tumors, uterine tumors resembling ovarian sex cord tumors, BCOR/BCORL1-altered high-grade endometrial stromal sarcomas, and inflammatory myofibroblastic tumors. Novel developments in epithelioid and myxoid leiomyosarcomas are briefly discussed, and differential diagnoses with key diagnostic criteria are provided for morphologic mimickers.

Hereditary Gynecologic Cancer Syndromes - A Narrative Review

Hereditary cancer syndromes are defined as syndromes, where the genetics of cancer are the result of low penetrant polymorphisms or of a single gene disorder inherited in a mendelian fashion. During the last decade, compelling evidence has accumulated that approximately 5-10% of all cancers could be attributed to hereditary cancer syndromes. A tremendous progress has been made over the last decade in the evaluation and management of these syndromes. However, hereditary syndromes associated with gynecologic malignancies still present significant challenge for oncogynecologists. Oncogynecologists tend to pay more attention to staging, histological type and treatment options of gynecological cancers than thinking of inherited cancers and taking a detailed family history. Moreover, physicians should also be familiar with screening strategies in patients with inherited gynecological cancers. Lynch syndrome and hereditary breast-ovarian cancer syndrome are the most common and widely discussed syndromes in medical literature. The aim of the present review article is to delineate and emphasize the majority of hereditary gynecological cancer syndromes, even these, which are rarely reported in oncogynecology. The following inherited cancers are briefly discussed: Lynch syndrome; "site-specific" ovarian cancer and hereditary breast-ovarian cancer syndrome; Cowden syndrome; Li-Fraumeni syndrome; Peutz-Jeghers syndrome; ataxia-telangiectasia; DICER1- syndrome; gonadal dysgenesis; tuberous sclerosis; multiple endocrine neoplasia type I, II; hereditary small cell carcinoma of the ovary, hypercalcemic type and hereditary undifferentiated uterine sarcoma; hereditary diffuse gastric cancer and MUTYH-associated polyposis. Epidemiology, pathogenesis, diagnosis, pathology and screening of these syndromes are discussed. General treatment recommendations are beyond the scope of this review.

Ectopic pregnancy of the fundal myometrium in a patient with tuberous sclerosis

A myometrial ectopic pregnancy is a rare and potentially fatal diagnosis. This diagnosis should be considered when presented with large increases in serum beta-hCG with no evidence of an intrauterine pregnancy, particularly with altered myometrium.

Gynaecological perivascular epithelioid cell tumour (PEComa): comparative analysis of proposed algorithms for prediction of clinical outcome

AIMS

Perivascular epithelioid cell tumours (PEComas) are rare mesenchymal tumours that coexpress smooth muscle and melanocytic markers. They have a predilection for gynaecological organs, where they present a unique diagnostic challenge, because of morphological and immunohistochemical overlap with more common smooth muscle and stromal tumours. Limited information regarding the natural history, owing to the rarity of this tumour, makes accurate risk stratification difficult. We aimed to review clinicopathological features of gynaecological PEComa and compare accuracy of five different classification systems for prediction of prognosis.

METHODS AND RESULTS

We have described the clinicopathological features of 13 new cases and tested five prognostic algorithms in a total of 67 cases of gynaecological PEComa. Receiver operating characteristic curves were constructed and areas under the curve (AUCs) were calculated to evaluate predictive accuracy. The modified gynaecological-specific algorithm showed high sensitivity and specificity and yielded the highest AUC (0.864). It's earlier version, the gynaecological-specific algorithm, suffered from lower specificity (AUC = 0.843). The post-hoc McNemar test confirmed significant differences between the performances of the modified gynaecological-specific algorithm and the gynaecological-specific algorithm (P = 0.008). The original Folpe algorithm for PEComas of all sites showed low specificity, had a lower AUC (0.591), and was inapplicable in 18% of cases. Its two later versions (the revised Folpe algorithm and the modified Folpe algorithm) also yielded lower AUCs (0.690 and 0.591, respectively).

CONCLUSION

We have shown that the modified gynaecological-specific algorithm predicts the clinical outcome of gynaecological PEComa with high accuracy, and have validated its use for prognostic stratification of gynaecological PEComa.

Perivascular epithelioid cell tumors (PEComa) of the gynecologic tract

PEComas of the female genital tract are rare mesenchymal neoplasms that are most common in the uterus, but also may occur in other gynecologic locations. As they morphologically and immunohistochemically resemble smooth muscle tumors, distinction between the two entities is often challenging, and may be aided by molecular analysis. Thus far, two distinct molecular groups-classic PEComas with TSC mutations and TFE3-translocation associated PEComas with TFE3 fusions have been described. Recognition of the first group is imperative as these patients may benefit from targeted therapy with mTOR inhibitors, if malignant. This review will focus on recognition of the morphologic and immunophenotypic features of PEComas, as well as the role of molecular testing in their diagnosis and treatment, analysis of the different algorithms to predict behavior, and differential diagnosis.

Perivascular epithelioid cell tumors (PEComa) of the female genital tract: A challenging question for gynaecologic oncologist and pathologist

Perivascular epithelioid cell tumors (PEComa)s are mesenchymal neoplasms composed of perivascular epithelioid cells, which express both melanocytic and myogenic markers. These neoplastic cells are thought to arise from undifferentiated cells of the neural crest, or from myoblastic cells harbouring a molecular alteration leading to expression of melanocytic markers, or from pericytic cells. The majority of cases are benign, but a small subset behaves in a malignant fashion. Unfortunately, given their rarity, reliable criteria for predicting malignancy have yet to be established. PEComas of the female genital tract account for nearly 25% of PEComas of all body sites, and the most common site of occurrence is the uterine corpus; less common sites include the cervix, adnexa, vagina/vulva or broad or round ligament exceptionally. The present review aims to elucidate the clinical, pathological and molecular features of gynecological PEComas. Moreover, prognostic and therapeutic implications are also discussed.

Local PEComatosis of the Appendix: New Insights Into the Histogenesis of Nodular Granular Muscle Degeneration and Granular Cells/Granular Cell Lesions of the Appendix

Nodular granular muscle degeneration (NGMD) of the appendix is a rare histologic curiosity characterized by distinctive nests of polygonal epithelioid cells with abundant pale-pink eosinophilic granular cytoplasm, mostly distributed in the inner layer of the muscularis propria or submucosa of the appendix. Although the nature of the cells of interest in NGMD of the appendix has not been completely elucidated, it is believed that they denote degenerative smooth muscle cells of the appendiceal muscularis propria, a histologic finding described as granular cells/granular cell lesions of the appendix in the 1960s. In this article, we described a new case of NGMD of the appendix and documented for the first time that this peculiar lesion actually represents a form of perivascular epithelioid cell proliferation based on its dual immunopositivity for myogenic and melanocytic markers. We also analyzed the old medical literature on granular cells/granular cell lesions of the appendix to shed some light on this ill-defined morphologic finding and its relationship to NGMD of the appendix. Since NGMD of the appendix is a lesion of perivascular epithelioid cells, the term NGMD is a misnomer, and hence, the designation "local PEComatosis of the appendix" is proposed for this unusual phenomenon.

Uterine PEComa with aggressive behavior: A review with an additional case of spontaneous vaginal expulsion

Perivascular epithelioid cell tumor (PEComa) is a rare mesenchymal tumor originating from perivascular epitheloid cells showing melanocytic and smooth muscle differentiation. The uterus represents the second most common site of origin. A 49 years woman presented to our Hospital for a vaginal spontaneous expulsion of a mass suggestive for malignant mesenchymal tumor. The patient underwent total hysterectomy and bilateral salpingo-oophorectomy and the histopathological report was compliant with a PEComa with aggressive behavior. Medical Literature databases about PEComa were searched. The current literature identified near 90 cases of uterine PEComas and they are categorized as uncertain malignant potential or with aggressive behavior. Primary surgical excision represents the gold-standard treatment. Recently targeted therapy with mTOR inhibitors has been introduced with an important beneficial. In this paper we review the Literature about the uPEComa with aggressive behavior reporting the first case of spontaneous vaginal expulsion.

Perivascular Epithelioid Cell Tumor of the Urinary Bladder: A Systematic Review

Perivascular epithelioid cell tumor (PEComa) of the urinary bladder is a rare neoplasm showing distinct melanocytic and smooth muscle differentiation. We aimed to review the clinicopathologic features of bladder PEComa using all the available cases in the literature, along with 2 new cases from our database. The patients included 15 females and 15 males with a mean age of 39.2 ± 15.3 years. Painless hematuria was the most common clinical presentation. The tumors were usually well circumscribed with a mean tumor size of 4.4 ± 2.7 cm. Bladder PEComas demonstrated nests, trabeculae, or sheets of epithelioid cells with intermixed spindled cells and numerous thin-walled vessels. Immunohistochemical studies showed that the tumors were positive for HMB45 (27/27), cathepsin (4/4), SMA (20/22), and caldesmon (3/3) and were negative for pan cytokeratin (0/18) and EMA (0/4). Molecular studies revealed that PEComa was associated with the TFE3 (n = 3) and EWSR1 (n = 1) gene rearrangements. Treatment included partial cystectomy (n = 18), transurethral resection (n = 8), and radical cystectomy (n = 4). Twenty patients had no evidence of disease during a mean follow-up time of 19.4 ± 17.2 months. Two patients had recurrence, and 1 patient died of metastatic disease. In conclusion, bladder PEComas demonstrate distinct morphologic and immunohistochemical features. Although most tumors follow a benign course, a small subset may develop metastasis and cause death.

Less common manifestations in TSC

Tuberous sclerosis complex (TSC) is due to pathogenic variants in TSC1 or TSC2 genes resulting in hyperactivation of the mTOR pathway. Many organ systems can be affected, such as brain, skin, eye, heart, bone, kidney, or lung. Typical lesions of TSC usually are those included as major criteria, including angiofibromas, hypomelanotic macules, tubers, subependymal nodules, angiomyolipomas, cardiac rhabdomyomas, and lymphangioleiomyomatosis. However, there are many other manifestations less frequent and/or less well known, many of them not included as clinical diagnostic criteria that are part of the clinical spectrum of TSC. The focus of this review will be on these less common and less well-known manifestations of TSC. Among the rare manifestations, we will discuss some clinical findings including arteriopathy, arachnoid cysts, lymphatic involvement, chordomas, gynecological, endocrine, and gastrointestinal findings. Among the manifestations that are very frequent but much less well known, we find the sclerotic bone lesions. Although they are very frequent in TSC they have been largely overlooked and not considered diagnostic criteria, mainly because they are asymptomatic. However, it is important to know their typical characteristics to avoid misdiagnosing them as metastasis.

Uterine Mesenchymal Tumors: Hereditary Aspects

The topic of hereditary gynecologic malignancies readily evokes associations between Lynch syndrome and endometrial adenocarcinoma, or between BRCA mutations and tubo-ovarian serous carcinoma, but other familial associations are less well-known. Two hereditary syndromes are known to be related to uterine mesenchymal tumors: hereditary leiomyomatosis and renal cell carcinoma syndrome and the tuberous sclerosis complex. In the following review, we describe the current literature on these syndromes, summarizing their clinical, morphologic, immunophenotypic, and genetic data. It is possible that the surgical pathologic diagnosis is the first indication of a familial syndrome, thus emphasizing the importance of a pathologist's familiarity with these potentially suggestive lesions.

Uncommon hereditary gynaecological tumour syndromes: pathological features in tumours that may predict risk for a germline mutation

The most common hereditary gynaecological tumour syndromes are hereditary breast and ovarian cancer syndrome and Lynch syndrome. However, pathologists also may encounter gynaecological tumours in women with rare hereditary syndromes. Many of these tumours exhibit distinctive gross and microscopic features that are associated with a risk for an inherited gene mutation. The sensitivity and specificity of these tumour pathology features for predicting an inherited mutation vary depending on the syndrome. By recognising these tumour features, pathologists may potentially contribute to the diagnosis of an unsuspected syndrome by recommending referral of the patient for formal risk assessment by genetic counselling. Patients additionally benefit from diagnosis of an inherited syndrome because many also carry a lifetime risk for developing primary malignancies outside of the gynaecological tract. Early diagnosis of an inherited syndrome permits early screening, detection, and management of additional malignancies associated with the syndrome. This review highlights these rare syndromes and their tumour pathology, including Peutz-Jeghers syndrome (gastric type mucinous carcinoma of the cervix; ovarian sex cord tumour with annular tubules); hereditary leiomyoma renal cell carcinoma syndrome (uterine leiomyoma); tuberous sclerosis complex (uterine PEComa; uterine lymphangioleiomyomatosis); DICER1 syndrome (ovarian Sertoli-Leydig cell tumour; cervical embryonal rhabdomyosarcoma); rhabdoid tumour predisposition syndrome 2 (small cell carcinoma of the ovary, hypercalcaemic type); Cowden syndrome (endometrial endometrioid adenocarcinoma); naevoid basal cell carcinoma syndrome (ovarian fibroma); and Von Hippel-Lindau syndrome (clear cell papillary cystadenoma of the broad ligament).

Gynecologic Manifestations of Less Commonly Encountered Hereditary Syndromes

This review covers gynecologic manifestations that may occur in rare hereditary syndromes. Recent advances in disorders, such as hereditary leiomyomatosis, renal cell carcinoma syndrome and tuberous sclerosis complex, are discussed as well as lesions that occur in von Hippel-Lindau syndrome, nevoid basal cell carcinoma syndrome, Cowden syndrome, Ollier disease/Maffucci syndrome, and Carney complex. Characteristic clinicopathologic features of each of these syndromes are discussed with an emphasis on the key features that enable pathologists to identify patients at highest risk for these diseases.

Perivascular Epithelioid Cell Tumor of the Uterus with Ovarian Involvement: A Case Report and Review of the Literature

Patient: Female, 61

Final Diagnosis: Uterine PEComa with ovarian involvement

Symptoms: Palpable abdominal mass

Medication: —

Clinical Procedure: Hysterectomy and bilateral salpingo-oophorectomy

Specialty: Obstetrics and Gynecology

Incidental Pelvic and Para-aortic Lymph Node Lymphangioleiomyomatosis Detected During Surgical Staging of Pelvic Cancer in Women Without Symptomatic Pulmonary Lymphangioleiomyomatosis or Tuberous Sclerosis Complex

Extrapulmonary lymphangioleiomyomatosis (LAM) is a rare neoplasm of spindle cells exhibiting melanocytic and myoid differentiation that arises as a mass in the mediastinum, retroperitoneum, uterine wall, and/or intraperitoneal lymph nodes. Many patients also have pulmonary LAM, tuberous sclerosis complex (TSC), and/or other neoplasms of the perivascular epithelioid cell tumor family. This study reports 26 patients with clinically occult LAM involving pelvic/para-aortic lymph nodes removed from women undergoing surgical staging of a uterine (17), ovarian (5), cervical (3), or urinary bladder (1) neoplasm. None of the patients exhibited symptoms of pulmonary LAM, and the median patient age (56 y) was older than what would be expected for patients presenting with pulmonary LAM. Only 2/26 patients had TSC. Four patients also had uterine LAM. One of these 4 had uterine perivascular epithelioid cell tumor, and 1 had vaginal angiomyolipoma. In all 26 patients the lymph node LAM was grossly occult, measured 3.5 mm on average (1 to 19 mm), and involved either a single lymph node (12/26) or multiple lymph nodes (14/26). HMB45 was positive in 24/25 cases, mostly in a focal or patchy distribution. Other melanocytic markers included MiTF (12/14) and MelanA (2/12). Myoid markers included smooth muscle actin (23/23) and desmin (15/16), mostly in a diffuse distribution. Estrogen receptor was positive in all cases tested, as was D240 expression in the lymphatic endothelium lining the spindle cell bundles. Concurrent findings in the involved lymph nodes included metastatic carcinoma (3/26), endosalpingiosis (3/26), and reactive lymphoid hyperplasia (13/26). This study demonstrates that clinically occult lymph node LAM can be detected during surgical staging of pelvic cancer and is not commonly associated with pulmonary LAM or TSC, although these patients should still be formally evaluated for both of these diseases.

Perivascular epithelioid cell tumor of the uterine cervix identified on a conventional cervical smear

Perivascular epithelioid cell tumors (PEComas) most frequently involve the uterus, particularly the uterine corpus and very occasionally the cervix. One case of PEComa identified using a conventional cervical smear has previously been documented. Herein, we present the second such case. The patient was a 51-year-old woman with abnormal genital tract bleeding. Samples collected for conventional cervical smears were submitted for cytopathological examination, which revealed discohesive monotonous tumor cells showing epithelioid morphology, ample cytoplasm that was pale to weakly eosinophilic, and mildly enlarged nuclei. The cytopathological features were well correlated with histopathological findings. Upon immunohistochemistry, the tumor cells were positive for both melanocytic and smooth muscle markers. Based on these findings, PEComa was diagnosed. Subsequently, a total hysterectomy with bilateral salpingo-oophorectomy was performed, revealing that the tumor (28 × 22 × 12 mm) was located at the superficial part of the endocervix. We propose that the cytopathological findings described herein can guide the diagnosis of PEComa, even though this tumor is rare.

PEComa: morphology and genetics of a complex tumor family

Perivascular epithelioid cell tumors, or PEComas, are mesenchymal neoplasms composed of histologically and immunohistochemically distinctive epithelioid or spindle cells, which are immunoreactive for both smooth muscle and melanocytic markers. The cells in PEComas are typically arranged around blood vessels and appear to form the vessel wall, often infiltrating the smooth muscle of small- to medium-sized vessels. Periluminal cells are usually epithelioid and the more peripheral cells are spindle shaped. The cells have small, round to oval nuclei, sometimes with focal nuclear atypia, and clear to eosinophilic cytoplasm, and no counterpart normal cell has been identified. The PEComa "family" now includes angiomyolipoma, pulmonary clear cell "sugar" tumor and lymphangioleiomyomatosis, primary extrapulmonary sugar tumor, clear cell myomelanocytic tumor of the falciform ligament/ligamentum teres, abdominopelvic sarcoma of perivascular epithelioid cells, and other tumors with similar features at various sites that are simply termed PEComa. Some PEComas occur in patients with tuberous sclerosis complex and share the genetic abnormalities. There is a behavioral spectrum from benign to frankly malignant, and histologic criteria have been proposed for assessing malignant potential. The differential diagnosis can include carcinomas, smooth muscle tumors, other clear cell neoplasms, and adipocytic tumors. PEComas constitute a genetically diverse group that includes neoplasms harboring TFE3 gene rearrangements and those with TSC2 mutations, indicating alternative tumorigenic pathways. Recent advances in therapy of malignant PEComas relate to increased knowledge of specific genetic changes and their effects on metabolic pathways that are susceptible to specific interventions. We review PEComas, emphasizing the diagnostic spectrum and recent immunohistochemical and genetic findings.

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.

Microscopic endometrial perivascular epithelioid cell nodules: a case report with the earliest presentation of a uterine perivascular epithelioid cell tumor

Abstract

Perivascular epithelioid cell (PEC) tumors (PEComas) are a family of related mesenchymal tumors composed of PECs which co-express melanocytic and smooth muscle markers. Although their distinctive histologic, immunohistochemical, ultrastructural, and genetic features have been clearly demonstrated, their histogenesis and normal counterpart remain largely unknown. Precursor lesions of PEComas have rarely been reported. We herein describe a tuberous sclerosis patient with microscopic PEC nodules in the endometrium of adenomyosis, pelvic endometriosis, an ovarian endometriotic cyst, and the endometrium of the uterine cavity. The nodules showed a mixture of spindle-shaped and epithelioid cells concentrically arranged around small arteries. The cells exhibited uniform nuclei, light eosinophilic cytoplasm, and immunoreactivity with HMB-45 and CD10. Some nodules revealed continuity with a PEComa in the myometrium. These findings support microscopic endometrial PEC nodules possibly being precursor lesions of uterine PEComas. The wide distribution of the nodules in the pelvis may be related to the multicentricity of PEComas in tuberous sclerosis patients. Owing to the immunoreactivity with CD10, microscopic endometrial PEC nodules may be misinterpreted as endothelial stromal cells unless melanocytic markers are stained. To the best of our knowledge, this is a case with the earliest manifestation of PEC lesions occurring in the endometrium.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9658280017862643

Uterine angiosarcoma associated with lymphangioleiomyomatosis in a patient with tuberous sclerosis complex: an autopsy case report with immunohistochemical and genetic analysis

A 41-year-old woman carrying a germline tuberous sclerosis complex 2 (TSC2) mutation, whose regular medical follow-up for tuberous sclerosis complex and tuberous sclerosis complex-associated lymphangioleiomyomatosis had continued for 2 years, had uterine angiosarcoma concomitant with uterine lymphangioleiomyomatosis. Immunohistochemically, the uterine angiosarcoma cells showed an extremely skewed lymphatic differentiation; they were diffusely immunopositive for CD31 but negative for other vascular endothelial markers including factor VIII and CD34 yet strongly immunopositive for lymphatic endothelial markers including D2-40 and Prox-1. Loss of heterozygosity analysis demonstrated that not only lymphangioleiomyomatosis and renal angiomyolipoma but also the uterine angiosarcoma had loss of heterozygosity on TSC2. Furthermore, direct sequencing revealed a TP53 mutation in the uterine angiosarcoma. Collectively, the findings suggest that combined dysfunction of the p53 and TSC2 tumor suppressor proteins may contribute to the development of uterine angiosarcoma in this rare clinical setting.

Multifocal PEComa (PEComatosis) of the female genital tract and pelvis: a case report and review of the literature

Perivascular epithelioid cells (PECs) are constantly present in a group of tumors called PEComas, including angiomyolipoma (AML), clear-cell "sugar" tumor (CCST) of the lung and extrapulmonary sites, lymphangioleiomyomatosis, clear-cell myomelanocytic tumor of the falciform ligament/ligamentum teres and rare clear-cell tumors of other anatomic sites. PECs have distinctive morphologic, immunohistochemical, ultrastructural and genetic characteristics, including an epithelioid appearance with a clear to granular cytoplasm, a round to oval, centrally located nucleus, and an inconspicuous nucleolus. PECs also express melanocytic and myogenic markers like HMB45 and smooth muscle actin. PEComa is rare in human, and multifocal PEComas (PEComatosis) is extremely rare. Up to now there have been only less than 5 cases described in the literature. Here we report a 46-year old Chinese woman who had PEComatosis arising from the genital tract and pelvis. To our knowledge, this is the first case of PEComatosis ever reported in China.

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.

Intramural pregnancy presenting in a patient with tuberous sclerosis

Intramural pregnancies are a rare form of ectopic pregnancy located within the myometrium separate from the endometrial cavity. In an effort to prevent potential complications, diagnosis should be made early when more conservative approaches can be performed to preserve reproductive potential. The diagnosis of ectopic pregnancies can be successfully accomplished through sonography; however, intramural pregnancies may be difficult to diagnose as they can appear similar to other etiologies. We present a unique case of a ruptured intramural pregnancy diagnosed with sonography and pelvic MRI in a patient with tuberous sclerosis. Surgical enucleation of the intramural pregnancy was successfully performed with postoperative resolution of beta hCG levels.

Lymphangioleiomyomatosis, Multifocal Micronodular Pneumocyte Hyperplasia, and Clear-Cell Micronodules in a 39-Year-Old Woman With Tuberous Sclerosis: A Case Report

This study reports the case of a 39-year-old woman with tuberous sclerosis complex (TSC) combined lymphangioleiomyomatosis (LAM), multifocal micronodular pneumocyte hyperplasia (MMPH), and clear-cell micronodules. She had repetitious bilateral pneumothoraces, and chest radiography revealed diffuse thin-walled cysts and multiple nodules. Bilateral renal angiomyolipomas (AMLs) and cerebral periventricular spots were also present. Lung biopsy revealed dilated airspace with HMB-45-positive spindle cell infiltration and aggregation indicative of LAM. Randomly distributed nodules of proliferative type II pneumocytes were consistent with MMPH. Clear-cell micronodules comprised nodular aggregation of HMB-45-positive polygonal cells with clear cytoplasm. Abnormal migration and proliferation of HMB-45 immunoreactive perivascular epithelioid cells (PEComas) is posited to indicate LAM and AML histogenesis. Clear-cell micronodules are also believed to be one of the families of PEComas and are reported in association with TSC. These behaviors of perivascular epithelioid cells may play a role in TSC.

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.

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.