Solitary fibrous tumour and haemangiopericytoma: evolution of a concept

Haemangiopericytoma (HPC) was described in 1942 by Stout and Murray as a distinctive soft tissue neoplasm, presumably of pericytic origin, exhibiting a characteristic well-developed "staghorn" branching vascular pattern. Over the years, it appeared that this growth pattern was a non-specific one, shared by numerous, unrelated benign and malignant lesions, and that HPC was better considered as a diagnosis of exclusion. Three categories of lesion may now be individualized within the heterogeneous group of HPC-like neoplasms. The first category corresponds to those non-HPC neoplasms that occasionally display HPC-like features (e.g. synovial sarcoma). Lesions belonging to the second category show clear evidence of myoid/pericytic differentiation and correspond to true HPCs. They generally show a benign clinical course, and include glomangiopericytoma/myopericytoma, infantile myofibromatosis (previously called infantile HPC), and a subset of sinonasal HPCs. The third category is the solitary fibrous tumour (SFT) lesional group, which includes fibrous-to-cellular SFTs, and related lesions such as giant cell angiofibromas and lipomatous HPCs. In practice, any HPC-like lesion can be allocated to one of these categories, leaving the ill-defined "haemangiopericytoma" category empty.     

胰腺肌周细胞瘤的病理特征及诊治（附1例报告并文献复习）

目的探讨胰腺肌周细胞瘤的病理特征及其诊治。方法报告本院收治的1例胰腺肌周细胞瘤,并复习近年来国内外文献肌周细胞瘤的临床病理特征、诊断、鉴别诊断、治疗及预后。结果胰腺肌周细胞瘤为具有嗜酸性/嗜双性的圆形、卵圆形细胞围绕血管腔形成的典型的同心圆状结构。血管周同心圆Υ排列的肌样细胞表达SMA及Actin阳性,而其他肌性标记物Desmin、S-100蛋白、HBM45及CD34等为阴性。结论胰腺肌周细胞瘤属于良性肿瘤,临床表现无特异性,确诊须靠病理组织学检查,完整切除肿瘤是本病的理想治疗方法。     

前纵隔恶性肌周皮细胞瘤1例

<正>患者男,52岁,因"胸闷、胸痛、咳嗽1周,加重1天"入院。体格检查:右侧肺部叩诊为浊音。实验室检查无异常。胸部CT平扫:右前纵隔见类圆形软组织肿块,边界清晰,密度不均,内见大片低密度影(CT值13HU)及结节状略高密度影(CT值38HU),大小124mm×81mm×98mm;增强后病变呈不均匀中等强化,内见小血管穿行,病变与周围结构分界清楚,心脏受     

下肢肌周细胞瘤一例

患者,女,33岁。因右小腿皮肤丘疹30余年,伴红肿疼痛3个月。予以手术切除,术后病理示：瘤细胞以多层同心圆型围绕薄壁血管周围生长,部分可见血管管腔闭塞。免疫组化示：ERG(血管+),CD34(血管+),CD31(血管+),SMA(+),Desmin(-),H-caldesmon(+)。结合形态学及免疫组化考虑肌周细胞瘤。予以手术扩大切除后植皮。     

Myopericytoma of the neck: sonographic appearance and sonographically guided needle biopsy

We report the imaging and pathologic findings of a case of myopericytoma of the neck in a 70-year-old woman, which was diagnosed by ultrasound-guided core-needle biopsy. The mass demonstrated homogeneous intense enhancement on contrast-enhanced CT and was markedly hypervascular on power Doppler sonography. The histopathological findings of the core biopsy were consistent with myopericytoma.     

Imaging features of myopericytoma arising from the parotid gland: Report of 2 cases and literature review

Rationale:Myopericytoma of the parotid gland is a rare condition of which preoperative definitive diagnosis is relatively challenging. The purpose of this case report is to highlight the radiologic features of myopericytoma of parotid gland.Patient concerns:A 62-year-old man presented with a history of a walnut-size mass in left parotid gland when yawned for half-month, and a 48-year-old woman complaint about a grape-size, painless mass behind the right ear for a month.Diagnoses:Radiological examinations suggested that both lesions were cyst-solid mixed lesions with relatively smoothed margins, with or without significant enhancement while the lesion without enhancement had a hemorrhage. Then a diagnosis of benign tumor arising from the parotid gland was made. Final diagnosis of myopericytoma was confirmed by histopathological and immunohistochemical examinations after surgical resection.Interventions:Both patients underwent excision of the tumor and the superficial parotidectomy with facial nerve preservation.Outcomes:Both patients recovered without any intraoperative or postoperative complication and had no signs of recurrence during a 17-month and 5-year follow-up.Lessons:Parotid gland myopericytoma is an exceedingly rare tumor which diagnosis can be challenging, and this is the first published report specifying the magnetic resonance features of the disease.     

Extra-uterine myoid tumours in patients with acquired immunodeficiency syndrome: a clinicopathological reappraisal

Ramdial P K, Sing Y, Deonarain J, Vaubell J I, Naicker S, Sydney C, Hadley L G P, Singh B, Kiratu E, Gundry B & Sewram V
(2011) Histopathology  59 , 1122–1134
Extra‐uterine myoid tumours in patients with acquired immunodeficiency syndrome: a clinicopathological reappraisal Aims: AIDS‐associated myoid tumours (AIDS‐MTs), often Epstein–Barr virus (EBV)‐associated (EBV‐positive MTs), include smooth muscle tumors (SMTs) and the relatively recently recognized myopericytomas (MPCTs). The myoid immunophenotype of AIDS‐MTs has been documented inconsistently. The aim of this study was to reappraise the phenotypic and immunophenotypic features of extra‐uterine AIDS‐MTs and the clinical profile of afflicted patients. Methods and results: EBV early RNA in‐situ hybridization testing on 27 AIDS‐MTs from 25 patients identified 19 of 27 (70.4%) EBV‐positive MTs and eight of 27 (29.6%) EBV‐negative MTs. EBV‐positive MTs comprised 12 of 19 EBV‐positive SMTs [six leiomyomas, one smooth muscle tumour of uncertain malignant potential (STUMP), five leiomyosarcomas] and seven of 19 EBV‐positive MPCTs [benign (five), malignant (two)]. The EBV‐negative MTs, made up exclusively of EBV‐negative SMTs, included angioleiomyoma (one), leiomyoma (one), STUMP (one) and leiomyosarcomas (five). Malignant AIDS‐MTs demonstrated hypercellularity, pleomorphism, increased mitoses and necrosis. EBV‐positive leiomyosarcomas retained a conspicuous fascicular architecture. Four of five EBV‐negative leiomyosarcomas demonstrated marked pleomorphism. All EBV‐positive MPCTs and two EBV‐positive leiomyosarcomas contained aggregates of desmin‐negative round and oval cells. Seventeen of 25 patients died, mainly from comorbid diseases. Conclusion: While the reappraised spectrum of AIDS‐MTs does not demonstrate divergent subtype‐determined clinical behaviour, heightened awareness/recognition of this expanded spectrum will not only promote improved diagnosis of pleomorphic and myopericytic variants, which may be the sentinel clue to AIDS and its comorbidity, but will also facilitate distinction from histopathological mimics in specific anatomic locations.     

Myopericytoma proliferating in an unusual anastomosing multinodular fashion

We herein describe a case of myopericytoma that proliferated in an unusual fashion. Myopericytoma is described as a group of rare, benign, dermal or subcutaneous tumors that are characterized histologically by a striking, concentric, perivascular proliferation of spindle cells and showing apparent differentiation towards perivascular myoid cells. Myopericytoma forms a morphological continuum with myofibroma/myofibromatosis, glomus tumor and angioleiomyoma. The patient was a 64‐year‐old woman who demonstrated a recurrent ulcer on an atrophic plaque on her left shin. A histopathological examination of the plaque demonstrated that tumor cells proliferated in an anastomosing multinodular fashion along the vessels in the dermis and subcutaneous tissue. In those nodules, there were numerous, small, concentric proliferations of myoid‐appearing spindle cells around small vascular lumina. The present case is an unusual example of myopericytoma, manifesting in a characteristic anastomosing, multinodular, infiltrating fashion.     

Perivascular myoma: case report with immunohistochemical and ultrastructural studies

A subcutaneous myopericytoma-type perivascular myoma arising in the elbow of a 61-year-old woman is described. The tumor was well demarcated and consisted microscopically of small ovoid and spindle cells arranged in a concentric fashion, surrounding small to medium-sized vessels and imparting a superficial resemblance to hemangiopericytoma. In some areas, the cellular whorls were separated by myxoid stroma. Cells located between cellular whorls appeared immature with scant cytoplasm but did not show distinct nuclear anaplasia, increased mitoses or foci of necrosis. Immunohistochemistry showed that constituent cells were positive for alpha-smooth muscle actin and desmin. Electron microscopy disclosed that the immature-looking cells, as well as the ovoid and spindle-shaped cells, possessed focal densities along with thin filaments, subplasmalemmal densities, pinocytotic vesicles and an external lamina. These ultrastructural and immunohistochemical features indicate a myoid nature of pericytic cells and justify this type of neoplasm being categorized as perivascular myoid tumor.