Hepatic perivascular epithelioid cell tumors:The importance of preoperative diagnosis

Accurate preoperative diagnosis is highly important for the treatment of perivascular epithelioid cell tumors(PEComas)because PEComas are mainly benign tumors and may not require surgical intervention.By analyzing the causes,properties and clinical manifestations of PEComas,we summarize the challenges and solutions in the diagnosis of PEComas.

Uterine epithelioid trophoblastic tumor with the main manifestation of increased human chorionic gonadotropin:A case report

BACKGROUND Epithelioid trophoblastic tumor(ETT)is an extremely rare malignant gestational trophoblastic neoplasm commonly presenting with abnormal vaginal bleeding,abdominal pain,and increased human chorionic gonadotropin(hCG).This study reported a case of uterine ETT with the main manifestation being increased hCG.CASE SUMMARY A 39-year-old female was referred to the Ningbo Maternal and Child Hospital of China in December 2022,complaining of increased hCG levels for 1 month.Magnetic resonance imaging revealed gestational trophoblastic tumor,and hysteroscopic electrotomy and curettage of intrauterine hyperplasia were performed.The patient was diagnosed with uterine ETT through postoperative pathological examination and immunohistochemical results.Total laparoscopic hysterectomy and bilateral salpingectomy were performed,and hCG levels returned to normal.The patient was without recurrence during the postoperative 3-month follow-up.CONCLUSION This study reported a case of uterine ETT with the main manifestation being increased hCG,highlighting that ETT should be considered in the presence of abnormal hCG.A total laparoscopic hysterectomy is recommended.

Massive simultaneous hepatic and renal perivascular epithelioid cell tumor benefitted from surgery and everolimus treatment:A case report

BACKGROUND Perivascular epithelioid cell tumor(PEComa)is a rare mesenchymal neoplasm that predominantly affects the kidney and uterus.The occurrence of this tumor in the liver,particularly with simultaneous involvement of the liver and kidney,is exceedingly uncommon.Pathological diagnosis is the gold standard.PEComas usually show positive immunohistochemical staining for melanocytic(HMB-45,Melan-A)and myoid(SMA,muscle-specific actin)markers.CASE SUMMARY We presented a noteworthy case of malignant PEComa affecting both the liver and kidney in a 53-year-old man with tuberous sclerosis complex(TSC).FAT2 and TP73 mutations in the kidney were identified and positive expression of diagnostic markers including HMB-45,Melan A,and TFE3 were detected.In addition,we demonstrated that hepatic artery perfusion chemotherapy was ineffective for hepatic PEComa,while surgery remained the most effective approach.Everolimus showed an excellent efficacy in the postoperative treatment of the tumor.CONCLUSION Surgical treatment is preferred for malignant PEComa affecting liver and kidney,especially with TSC;everolimus is effective postoperatively.

Epithelioid trophoblastic tumor of the lower uterine segment and cervical canal:A case report

BACKGROUND Epithelioid trophoblastic tumor(ETT) is the rarest type of gestational trophoblastic tumor(GTT). It has been reported that more than 50% of ETTs arise in the uterine cervix or the lower uterine segment. Here, we report a case of ETT within the lower uterine segment and cervical canal and discuss its manifestations,possible causes, and related influencing factors.CASE SUMMARY A 35-year-old woman(gravida 7, miscarriage 3, induction 2 with 1 being twins,para 2 of cesarean section, live 2), who had amenorrhea for 9 mo after breastfeeding for 22 mo after the last cesarean section, was diagnosed with ETT. The lesion was present in the lower uterine segment and endocervical canal with severe involvement of the anterior wall of the lower uterine segment and the front wall of the lower uterine segment where the cesarean incisions were made.Laboratory tests showed slight elevation of serum beta-human chorionic gonadotropin. Intraoperative exploration showed the presence of a normal-sized uterus body with an enlarged tumor in the lower uterine segment. The surface of the lower uterine segment was light blue, the entire lesion was approximately about 8cm × 8 cm × 9 cm, with compression and displacement of the surrounding tissue.Histological examination diagnosed ETT. Immunohistochemical analysis showed positive expression of p63, with a Ki-67 proliferation index of 40%.CONCLUSION A search of the PubMed database using the search terms "cesarean section" and "epithelioid trophoblastic tumor" retrieved nine articles, including 13 cases of ETT and ETT-related lesions, all 13 cases had a history of cesarean section, and the lesions were all located at the cesarean section incision on the anterior wall of the lower uterine segment. The present case is the 14th reported case of ETT after cesarean section. Therefore, we deduced that cesarean section trauma had an important effect on the occurrence of ETT at this site.

Hepatic perivascular epithelioid cell tumor in three patients

Perivascular epithelioid cell tumor （PEComa） is a rare, soft tissue tumor that can occur in various locations. The present report included three patients （one male and two females; age range, 25-51 years） with hepatic PEComas. The collected data included the clinical manifestations, diagnosis, management, treatment, and prognosis. Since it is difficult to diagnose hepatic PEComas by imaging, the patients were diagnosed by tumor tissue examination such as immunohistochemistry, which was positive for HMB-45, Melan-A, and SMA on all slides. The tumor was composed of diverse tissues including smooth muscle, adipose tissue, and thick-walled blood vessels. During the follow-up period, one of the tumors was malignant （double-positive for CD34 and Ki-67） and recurred 3 months after surgery. In addition, malignant hepatic PECo- mas were reviewed in the literature, indicating that the majority of hepatic PEComas are benign, but few hepatic PEComas exhibit malignant behaviors in older female patients （〉50 years of age） with abdominal discomfort and pain, larger tumor size （〉10 cm）, or positive staining for CD34 and Ki-67. In conclusion, there is no effective method to diagnose PEComas. Currently, the diagnosis of PEComas depends on immunohistochemical staining. Tumor resection and close follow-up are the principal methods for the management of PEComas.

Improving recognition of hepatic perivascular epithelioid cell tumor:Case report and literature review

A 58-year-old man presented with the chief complaint of abdominal bloating and was incidentally found to have a liver tumor.As diagnostic imaging studies could not rule out malignancy,the patient underwent partial resection of segment 3 of the liver.The lesion pathologically showed eosinophilic proliferation,in addition to immunohistochemical positivity for human melanoma black 45 and Melan-A,thereby leading to the diagnosis of a hepatic perivascular epithelioid cell tumor(PEComa).A PEComa arising from the liver is relatively rare.Moreover,the name ‘PEComa' has not yet been widely recognized,and the same disease entity has been called epithelioid angiomyolipoma(EAML),further diminishing the recognition of PEComa.In addition,PEComa imaging findings mimic those of malignant liver tumors,and clinically,this tumor tends to enlarge.Therefore,a PEComa is difficult to diagnose.We conducted a systematic review of PEComa and EAML cases and discuss the results,including findings useful for differentiating perivascular epithelioid cell tumors from malignant liver tumors.

A perivascular epithelioid cell tumor of the stomach:An unsuspected diagnosis

Perivascular epithelioid cell tumor(PEComa) is a rare mesenchymal neoplasia and currently well recognized as a distinct entity with characteristic morphological,immunohistochemical and molecular findings.We report a case of PEComa arising in the antrum of a 71-year-old female with melena.The tumor,located predominantly in the submucosa as a well delimited nodule,measured 3.0 cm in diameter and was completely resected,with no evidence of the disease elsewhere.Histologically,it was composed predominantly of eosinophilic epithelioid cells arranged in small nests commonly related to variably sized vessels,with abundant extracellular material,moderate nuclear variation and discrete mitotic activity.No necrosis,angiolymphatic invasion or perineural infil-tration was seen.Tumor cells were uniformly positive for vimentin,smooth muscle actin,desmin and melan A.Although unusual,PEComa should be considered in the differential diagnosis of gastric neoplasia with characteristic epithelioid and oncocytic features and prominent vasculature.

Hepatic perivascular epithelioid cell tumor:A case report

BACKGROUND Perivascular epithelioid cell tumor(PEComa)is a mesenchymal tumor with histologic and immunophenotypic characteristics of perivascular epithelioid cells,has a low incidence,and can involve multiple organs.PEComa originating in the liver is extremely rare,with most cases being benign,and only a few cases are malignant.Good outcomes are achieved with radical surgical resection,but there is no effective treatment for some large tumors and specific locations that are contraindicated for surgery.CASE SUMMARY A 32-year-old woman was admitted to our hospital with a palpable abdominal mass and progressive deterioration since the previous month.An ultrasoundguided percutaneous liver aspiration biopsy was performed.Postoperative pathological immunohistochemical staining was HMB45,Melan-A,and smooth muscle actin positive.Perivascular epithelioid tumor was diagnosed.The tumor was large and could not be completely resected by surgery.Further digital subtraction angiography revealed a rich tumor blood supply,and interventional embolization followed by surgery was recommended.Finally,the patient underwent transarterial embolization(TAE)combined with sorafenib for four cycles.Angiography reexamination indicated no clear vascular staining of the tumor,and the tumor had shrunk.The patient was followed up for a short period of time,achieved a stable condition,and surgery was recommended.CONCLUSION Adjuvant combination treatment with TAE and sorafenib is safe and feasible as it shrinks the tumor preoperatively and facilitates surgery.

Coincidence between malignant perivascular epithelioid cell tumor arising in the gastric serosa and lung adenocarcinoma

A 4-mo history of both epigastralgia and back pain was presented in a 39-year-old male. Computed tomography showed right lung nodule and abdominal mass attached to the gastric wall, measuring approximately 30 mm and 70 mm in diameter. Since biopsy samples from the lung and abdomen revealed poorly differentiated adenocarcinoma and malignant tumor, clinicians first interpreted the abdominal mass as metastatic carcinoma, and a right lower lobectomy with following resection of the mass was performed. Gross examination of both lesions displayed gray-whitish to yellow-whitish cut surfaces with hemorrhagic and necrotic foci, and the mass attached to the serosa of the lesser curvature on the gastric body. On microscopic examination, the lung tumor was composed of a proliferation of highly atypical epithelial cells having abundant eosinophilic cytoplasm, predominantly arranged in an acinar or solid growth pattern with vessel permeation, while the abdominal tumor consisted of sheets or nests with markedly atypical epithelioid cells having pleomorphic nuclei and abundant eosinophilic to clear cytoplasm focally in a radial perivascular or infiltrative growth pattern. Immunohistochemically, the latter cells were positive for HMB45 or α-smooth muscle actin, but the former ones not. Therefore, we finally made a diagnosis of malignant perivascular epithelioid cell tumor(PEComa) arising in the gastric serosa, combined with primary lung adenocarcinoma. Furthermore, small papillary car-cinoma of the thyroid gland was identified. The current case describes the coincidence of malignant PEComa with other carcinomas, posing a challenge in distinction from metastatic tumor disease.

Cutaneous perivascular epithelioid cell tumors:A review on an infrequent neoplasm

"Perivascular epithelioid cutaneous" cell tumors(PEComa) are a family of mesenchymal tumors with shared microscopic and immunohistochemical properties: They exhibit both smooth muscle cell and melanocytic differentiation. Non-neoplastic counterpart of PEComa's cells are unknown, as well as the relationship between extracutaneous PEComa and primary cutaneous ones. We will review the clinical setting, histopathologic features, chromosomal abnormalities, differential diagnosis and treatment options for cutaneous PEComa.

Pancreatic perivascular epithelioid cell tumor: A case report with clinicopathological features and a literature review

Perivascular epithelioid cell tumor(PEComa) of the pancreas is an unusual tumor deriving from mesenchyma. This paper described a case of pancreatic PEComa, which was initially suspected as neuroendocrine carcinoma by biopsy, and therefore surgical treatment was recommended due to undetermined diagnosis. Examination of the surgical specimen under a microscope showed that the tumor cell's morphology was epithelioid or spindle-shaped, and ranged in a nested pattern. Additionally, these cells had a large extent of acidophilic cytoplasm, no mitotic figures, and expressed HMB-45, melan-p, and smooth muscle actin immunohistochemically. Pathological examination indicated that PEComa originated from the pancreas, but symptoms related to tuberous sclerosis were absent. Since PEComa is extremely rare in the pancreas, it is likely to be ignored in differential diagnosis. In conclusion, our article highlighted the clinicopathological features of PEComa, and we conducted a literature review focusing on PEComa so as to deepen the understanding of this tumor type.

Perivascular epithelioid cell tumor of male pelvic cavity:a case report and literature review

Perivascular epithelioid cell tumors （PEComas） are a family of rare mesenchymal neoplasms. The PEComas, composed of epithelioid and spindle cells, have the same cellular and immtmohistocherrtical features but are found in different visceral and soft tissue sites. Here, we report the histological and immunohistochemical features of one case of PEComa restricted in the pelvic visceral peritoneum of a male patient. The patient was treated with radical surgery, and was well and on follow-up visits without tumor recurrence.

TFE3-expressing malignant perivascular epithelioid cell tumor of the mesentery:A case report and review of literature

BACKGROUND Perivascular epithelioid cell tumor(PEComa)is a rare mesenchymal tumor that exhibits an epithelioid and spindle cell morphology.The tumor is characterized by immunoreactivity for melanocytic and myogenic markers but can be misdiagnosed as more common tumors with similar characteristics,including gastrointestinal stroma tumors or leiomyosarcomas.Recently,a subset of PEComas has been reported to harbor a transcription factor binding to TFE3 fusion.Herein,we report a rare case of TFE3-expressing malignant PEComa arising from the mesentery.CASE SUMMARY A 50-year-old woman presented with abdominal discomfort for 3 months.Results of laboratory tests were all within the normal ranges,and the patient had no notable medical history.Magnetic resonance imaging revealed a large tumor on the right side of the pelvic floor,which was originally suspected to be a primary ovarian tumor.However,during surgery,the tumor was revealed to have originated from the mesentery.Histologically,the tumor was composed of bundles of spindle cells and sheets of epithelioid cells.Extensive coagulative necrosis and numerous mitotic figures were observed.Immunohistochemistry revealed that the tumor cells were positive for smooth muscle actin,HMB-45,and TFE3 expression.Tumor involvement of the rectal serosa was identified,leading to a final diagnosis of malignant PEComa of the mesentery.Surgical resection was followed by adjuvant chemotherapy.No recurrence or metastasis was observed over a 6-month follow-up period.CONCLUSION Malignant PEComa of the mesentery is extremely rare and should be distinguished from morphological mimics through differential diagnosis and immunohistochemistry.

Pediatric case of colonic perivascular epithelioid cell tumor complicated with intussusception and anal incarceration:A case report

BACKGROUND Perivascular epithelioid cell tumor(PEComa)represents a group of rare mesenchymal tumors.PEComa can occur in many organs but is rare in the colorectum,especially in children.Furthermore,PEComa is a rare cause of intussusception,the telescoping of a segment of the gastrointestinal tract into an adjacent one.We describe a rare case of pediatric PEComa complicated with intussusception and anal incarceration,and conduct a review of the current literature.CASE SUMMARY A 12-year-old girl presented with abdominal pain and abdominal ultrasound suggested intussusception.Endoscopic direct-vision intussusception treatment and colonoscopy was performed.A spherical tumor was discovered in the transverse colon and removed by surgery.Postoperative pathologic analyses revealed that the tumor volume was 5.0 cm×4.5 cm×3.0 cm and the tumor tissue was located in the submucosa of the colon,arranged in an alveolar pattern.The cell morphology was regular,no neoplastic necrosis was observed,and nuclear fission was rare.The immunohistochemical staining results were as follows:Human melanoma black 45(HMB 45)(+),cluster of differentiation 31(CD31)(+),cytokeratin(-),melanoma-associated antigen recognized by T cells(-),smooth muscle actin(-),molleya(-),desmin(-),S-100(-),CD117(-),and Ki67(positive rate in hot spot<5%).Combined with the results of pathology and immunohistochemistry,we diagnosed the tumor as PEComa.Postoperative recovery was good at the 4 mo follow-up.CONCLUSION The diagnosis of PEComa mainly depends on pathology and immunohistochemistry.Radical resection is the preferred treatment method.

Special epithelioid trophoblastic tumor:A case report

BACKGROUND Epithelioid trophoblastic tumor(ETT)is a special type of gestational trophoblastic tumor.However,its pathogenesis has been incompletely elucidated.ETT rarely occurs in the ovaries and fallopian tubes,unlike placental site trophoblastic tumor,requiring a histopathological biopsy and immunohistochemistry for further diagnosis.CASE SUMMARY A 29-year-old woman with irregular vaginal bleeding and elevated serum chorionic gonadotropin(β-hCG)levels presented similar symptoms to ectopic pregnancy.Transvaginal ultrasound revealed abnormal echoes of the left adnexa.Postoperatively,the pathology of the left ovary and fallopian tube was reported as ETT.The patient was followed up with regular hCG measurements and ultrasounds.The blood hCG values showed an upward trend 3 mo after the operation and then chemotherapy was prescribed.The current health status is normal.CONCLUSION For women of childbearing age with elevated serumβ-hCG levels,practitioners should consider ETT and be alert to the poor prognosis of the disease.After surgery,the patient’s condition should be closely observed to prevent recurrence and metastasis.Postoperative chemotherapy is only helpful for treating the disease to a certain extent.

Robotic wedge resection of a rare gastric perivascular epithelioid cell tumor: A case report

BACKGROUND Perivascular epithelioid cell tumor(PEComa) is a rare mesenchymal neoplasm that can arise in many different organs with a broad spectrum of biological behavior, from indolent to aggressive progression. Only ten cases of gastric PEComas have been reported in the English literature, which were treated with endoscopic, laparoscopic, or open resections. Due to its rarity, the optimal surgical management and prognosis of this tumor are still uncertain.CASE SUMMARY We present a case of robotic wedge resection of a 6.5 cm bleeding lesion of the gastric fundus located 3 cm below the esophago-gastric junction in a 55-year-old man. Biopsy revealed a malignant tumor with epithelioid cells focally positive for muscle markers desmin and smooth muscle actin. In addition, histology revealed that the tumor was positive for HMB-45, melan-A(MART-1), microphthalmia transcription factor and negative for pan-cytokeratin AE1/AE3, CD34, p40, DOG-1, CD117(c-kit), S100, CD3, CD79 a, caldesmon and myogenin. These markers suggested the possibility of a PEComa. The patient underwent a diagnostic laparoscopy via the da Vinci? Si? system and robotic wedge resection. Final pathology confirmed a malignant gastric PEComa with negative margins. At his 11-mo follow-up visit, the patient remained disease-free.CONCLUSION Gastric PEComa can be treated with a robotic R0 resection with acceptable postoperative and short-term oncological outcomes.

肾脏最大径大于4 cm的大体积上皮样血管平滑肌脂肪瘤临床特征分析

目的:分析大体积(最大径>4 cm)肾脏上皮样血管平滑肌脂肪瘤(EAML)的临床特征。方法:纳入2010至2021年在我院诊断为肾脏EAML,且符合纳入标准的30例患者,分析其临床、病理和治疗特点。结果:30例受试者中,男性12例,女性18例,年龄26~74岁。所有患者均行CT扫描。大多数EAML患者(23/30)在平扫CT图像上表现为相对于肾实质的高密度及以高密度为主的混杂密度,7例表现为低密度。完全性EAML的患者相对于部分EAML的患者,其肿块在平扫CT上表现为更大面积的高密度影。肿瘤最大径(8.7±6.6)(4.0~27.7)cm。所有患者均接受手术治疗并获得随访,随访时间24~150个月,中位随访时间59.5个月。随访患者中,1例死于肿瘤恶液质并伴有肝转移,3例出现同侧复发,1例患者出现肝转移,均为完全性EAML。结论:上皮样血管平滑肌脂肪瘤(EAML)是一种相对罕见的乏脂肪肾肿瘤。相对于小体积的EAML存在典型的CT表现,大体积的EAML在平扫CT上高密度特征已不再典型。只有少数EAML具有恶性潜能。手术治疗效果较好,但术后可能会出现复发和转移,尤其是老年患者,以及完全性EAML患者,建议密切随访。

卵巢恶性PEComa 1例报道并文献复习

目的:探讨卵巢原发恶性血管周上皮样肿瘤(perivascular epithelioid cell tumor,PEComa)的临床病理特征、诊断、鉴别诊断、治疗及预后。方法:对1例卵巢原发恶性PEComa进行常规病理学和免疫组化学标记分析并文献复习。结果:肿瘤由上皮样至梭形细胞组成,弥漫片状生长,部分区域可见瘤细胞围绕在血管周围呈放射状排列,瘤细胞胞质透亮或淡嗜伊红色,可见色素,见坏死及核分裂象。免疫组化:HMB45(+),Melan-A(+),TFE3(+),Ki-67 (指数<10%)。结论:卵巢原发恶性PEComa是一种罕见的表达黑色素标记和平滑肌标记的一组间叶性肿瘤,临床症状不典型,组织学形态及免疫标志物在诊断及鉴别诊断具有重要价值,术后影像学随访非常重要,免疫治疗及放射治疗仍值得探索。

肝脏血管周上皮样细胞瘤的CT、MRI表现和病理对照分析

目的探讨肝脏血管周上皮样细胞瘤(PEComa)患者的CT、MRI影像特征,对照病理分析,以提高对该病诊断的准确性。方法选取经病理证实为肝脏PEComa的8例患者的影像学资料,分析病灶形态及其内部影像学特征及强化特点,与病理对照分析并复习相关文献。结果8例(100%)肝脏PEComa均为单发,7例(87.5%)边缘清晰,大小平均为4.5cm,4例(50.0%)病变内部不均匀;影像学检查4例(50.0%)见脂肪成分,其中2例(25.0%)含有大量脂肪成分,5例(62.5%)可见血管畸形,8例(100%)均未见出血、坏死及钙化;增强扫描4例(50.0%)为“快进快出”,2例(25.0%)为“快进慢出”,2例(25.0%)为“持续强化”。结论肝脏PEComa女性多见,多数单发,CT、MRI影像学表现为边界清晰,病变内部不均匀,可含有脂肪及畸形血管,强化方式多样。

肾血管周上皮样细胞瘤诊疗研究进展

肾血管周上皮样细胞瘤(renal perivascular epithelioid cell tumor,PEComa)是起源于间质的罕见肿瘤,由独特的血管周上皮细胞组成,可累及身体多部位。诊断肾PEComa主要依靠病理学免疫组化,通过黑素细胞标记物和肌源性标记物的独特表达进行识别。其主要治疗方式为手术切除,预后良好。本文对肾PEComa的细胞组织来源、临床病理特点、诊断与治疗相关进展作一综述,旨在提供对这一罕见疾病的深入了解。