Cytologic features of alveolar soft part sarcoma: report of three cases

Alveolar soft part sarcoma (ASPS) is a rare, high-grade, epithelial-like sarcoma that shows characteristic histopathologic findings. Although a chromosomal anomaly that seems specific has been recently described, its diagnosis is based on histologic and ultrastructural features. The tumor shows no specific immunohistologic findings. Cytologic features of three cases of ASPS are presented. Preoperative fine-needle aspiration (FNA) of the primary soft tissue tumor was performed in two cases. In another two, mediastinal and pulmonary and subcutaneous metastatic lesions were aspirated. In all cases the cytologic image was identical with numerous, dissociated, large neoplastic cells with round-to-plasmocytoid morphology. Cytoplasmic fragility and granularity with abundant, atypical, naked nuclei were present. In one case, FNA material was available for ultrastructural studies. It disclosed the characteristic cytoplasmic crystalline structures. A specific cytologic diagnosis of ASPS was given in all cases. In conclusion, ASPS is a rare neoplastic entity that shows a characteristic cytologic image. When accompanied by an adequate clinical context it permits specific preoperative recognition. While immunocytologic studies are helpful to exclude other neoplasms, ultrastructure may result in an exact diagnosis.     

Metastatic alveolar soft part sarcoma of the lung: Metastatic alveolar soft part sarcoma of the lung‐a morphologic pitfall on cytology and aberrant CD10 expression on histology

Alveolar soft part sarcoma (ASPS) is a rare aggressive soft tissue sarcoma of young adults, typically arising in the deep soft tissue of lower extremities. Although cytomorphology is characteristic enough for an accurate diagnosis in typical clinical scenarios, problems arise when it occurs in older patients, atypical sites, or in primary evaluation at metastatic sites. A 48‐year‐old smoker presented with breathlessness and headache for 2 months. Imaging showed a heterogeneous enhancing lesion of 6 cm × 6 cm in right middle lobe of lung, smaller miliary nodules in bilateral lungs, multiple bilateral cerebral lesions, and a mass of 3 cm × 3 cm in the left thigh. Primary lung carcinoma with brain and thigh metastases was the clinical diagnosis. Fine‐needle aspiration smears of the lung lesion showed cohesive fragments of large cells with a prominent traversing branching capillary network and discohesion at periphery resulting in a pseudo‐papillary appearance. Tumor cells had fine granular to vacuolated cytoplasm, frayed borders, and prominent nucleoli. Trucut biopsy from the same showed a tumor arranged in nests composed of large polygonal cells, immunopositive for CD10. Possibility of metastatic renal cell carcinoma (RCC) was offered. Abdominal imaging was, however, normal. Core biopsy from thigh showed a similar tumor, immunonegative for epithelial markers, with cytoplasmic periodic‐acid‐schiff positive rhomboid crystals, clinching the final diagnosis of ASPS with lung and brain metastases. There is considerable morphological and immunohistochemical overlap between ASPS and RCC. Bare nuclei on air dried smears, binucleation, metachromatic basement membrane material are subtle pointers toward ASPS. Diagn. Cytopathol. 2016;44:250–254. © 2015 Wiley Periodicals, Inc.     

4例腺泡状软组织肉瘤临床病理分析及文献复习

目的：探讨腺泡状软组织肉瘤（alveolar soft-part sarcoma,ASPS）的临床病理学特征及其鉴别诊断。方法：对4例ASPS的临床资料进行回顾性分析,对标本进行组织病理学观察及免疫组织化学（免疫组化）研究。结果：患者3例为男性,年龄分别为30,25,27岁;1例为女性,34岁。发病部位4例均位于下肢深部软组织内。镜下肿瘤细胞排列成腺泡状或实性,细胞巢间可见窦状血管分隔,肿瘤细胞胞质丰富嗜酸,胞质内可见棒状结晶体。免疫组化：4例均TFE3阳性,3例MyoD1胞质阳性。1例患者随访15年后复发伴肺转移死亡,3例患者随访6个月无瘤存活。结论：ASPS是一种罕见的恶性肿瘤,青少年多见,结合临床、病理学特征及免疫组化,可做出正确诊断。鉴别诊断需除外腺泡状横纹肌肉瘤等血窦丰富的肿瘤,TFE3是该肿瘤的特异性标志物。     

Primary alveolar soft part sarcoma of the uterine cervix: a case report and literature review

Alveolar soft part sarcoma (ASPS) is a tumor of unknown histogenesis, composed of large, epithelioid cells with eosinophilic cytoplasm, having an alveolar pattern. Primary ASPS of uterine cervix is very rare. In this report, we present a 21-aged-old female with primary ASPS in the uterine cervix and discuss the clinicopathological characteristics, immunophenotype, molecular genetic feature and differential diagnosis of ASPS of cervix.     

Alveolar soft part sarcoma of the paranasal sinuses masquerading as a giant invasive pituitary adenoma

Alveolar soft part sarcoma (ASPS) is a relatively rare tumor that mostly presents as a slow growing mass in the deep soft tissue of the extremities. A substantial number of cases in children occur in the head and neck region; however, in any age group, it is very rarely reported in the sinonasal region. We report a case of ASPS of the paranasal sinuses with sellar extension in a 25-year-old man that masqueraded as a giant invasive pituitary adenoma. This is only the fifth case of sinonasal ASPS in literature. The clinical and radiological diagnoses were misleading, but an extensive pathology workup including electron microscopy helped reach an accurate diagnosis in this unusual case.     

Alveolar soft part sarcoma of the uterine corpus with pelvic lymph node metastasis: case report and literature review

Alveolar soft part sarcoma (ASPS) is a rare malignant soft tissue tumor, mainly localized in the extremities, occurring principally in adolescents and young adults. ASPS is uncommon in the female genital tract , and only 37 cases have been reported so far, including 9 cases in the uterine corpus and 17 cases in the uterine cervix. We here reported a case of ASPS occurring in the lower uterine segment . The case showed typical histological and immunohistochemical features. The patient had pelvic and para-aortic lymph node metastasis. To the best of our knowledge, it is the first such case described.     

Alveolar soft part sarcoma of the endometrium with expression of CD10 and hormone receptors

Alveolar soft part sarcoma (ASPS) is a rare tumor of uncertain histogenesis, mainly localized in the extremities. ASPS originating in the uterine corpus is quite rare; only eight such cases have been reported in the literature. We here present another case of ASPS found in the endometrium in a 50-year-old woman. Metastatic malignant tumor, including ASPS from other organs, was excluded by physical examination and imaging modalities. Thallium 201 was only localized in the uterus. The tumor showed characteristic histological features of ASPS: alveolar architecture with fibrovascular septa and abundant eosinophilic granular cytoplasm with periodic acid-Schiff-positive crystalline material. Diffuse nuclear immunoreactivity for TFE3, a marker recently reported to be specific for ASPS, further supported the diagnosis of ASPS. Interestingly, this tumor was negative for myogenic markers, but positive for CD10, progesterone receptor, and estrogen receptor. These immunohistochemical results and the tumor location suggest a possible link between endometrial stromal cells and the development of this tumor.     

儿童腺泡状软组织肉瘤13例临床病理学特征

目的探讨儿童腺泡状软组织肉瘤(alveolar soft part sarcoma,ASPS)的临床病理、分子遗传学特点、诊断及鉴别诊断。方法对北京儿童医院2009年8月至2018年11月13例儿童ASPS病例存档切片行HE染色及组织化学染色[包括过碘酸-雪夫(PAS)染色及淀粉酶消化PAS(D-PAS染色)]。采用免疫组织化学染色检测TFE3、INI1、CD68等的表达,应用荧光原位杂交(FISH)法检测TFE3基因断裂易位情况。结果13例ASPS中,男童4例,女童9例,年龄1岁2个月至13岁8个月,平均7.8岁,5岁以下4例。组织学上,11例肿瘤细胞呈腺泡状、巢状排列,2例肿瘤细胞呈实性、弥漫性生长。瘤细胞胞质嗜酸性,可见明显的空泡现象,核多形性,核仁突出,核分裂象罕见,3例可见血管浸润。免疫组织化学染色TFE3弥漫核阳性,INI1、CD68、波形蛋白阳性,MyoD1、Myogenin、细胞角蛋白、S-100蛋白等均阴性。7例PAS及D-PAS染色显示肿瘤细胞质内均可见紫红色针状或棒状结晶体。9例行FISH检测,均显示TFE3基因断裂易位。结论ASPS为儿童少见软组织肿瘤,肿瘤多位于深部肌肉内,瘤细胞排列成腺泡状或巢状,同时TFE3基因位点发生断裂易位,确定诊断需要结合临床、病理形态、免疫组织化学及基因检测综合考虑。     

Fine needle aspiration of alveolar soft part sarcoma in a child: Cytomorphological clues for the surgical pathologist

Alveolar soft part sarcoma (ASPS) is a rare soft tissue neoplasm generally affecting adolescents and young adults. Its unique histologic and ultrastructural features have been well-described; however, the cytopathological features of ASPS are less well-characterized, and recognition of this entity's features on cytologic preparations can ensure that the specimen adequacy and appropriate/rapid tissue allocation for additional testing. Herein we report a FNA case of ASPS with emphasis on cytomorphologic characteristics.     

Alveolar soft part sarcoma of the uterine cervix

We describe two cases of alveolar soft part sarcoma (ASPS) that occurred as a primary lesion in the uterine cervix. In both cases, the tumor exhibited the typical histologic features of ASPS. In one case, the material for immunohistochemical staining and electron microscopy was available, and the findings of these studies were consistent with the diagnosis of ASPS. A review of the literature disclosed seven previous cases of ASPS occurring in the female genital tract. The tumor was located in the uterine cervix in only three cases. Although ASPS most commonly involves the soft tissues of the extremities and the head and neck region, it can also occur in rather unusual locations such as the female genital tract. Pathologists should be aware of these unexpected occurrences.     

Cytoskeletal properties of alveolar soft part sarcoma

The immunohistochemical expression of cytoskeletal proteins in alveolar soft part sarcoma (ASPS) was studied by light and electron microscopy. Of the five cases examined by the avidinbiotin-peroxidase complex method, variable numbers of immunoreactive cells for desmin were found in three, for vimentin in two, for muscle-specific actins in three, and for alpha-smooth muscle actin in four. Immunoelectron microscopic study demonstrated that desmin and vimentin were localized on whorled bundles of intermediate filaments in the perinuclear cytoplasm. In addition, a few dispersed intermediate filaments became evident in specimens treated with saponin and fixed with tannic acid. These immunohistochemical results indicate that a few tumor cells of ASPS may express some properties of the cytoskeleton of smooth muscle cells in addition to those of skeletal muscle cells. Considering the discrepancies reported in the actin isoforms demonstrated in myogenic tumors, we conclude that ASPS is probably a peculiar, primitive myogenic tumor that does not show any distinctive features of rhabdomyogenic or leiomyogenic differentiation.     

Alveolar soft part sarcoma presenting as a breast metastasis in a patient with a history of thyroid cancer: a case report

Metastases to the breast are uncommon, accounting for 0.5% of breast tumors, and most of them are originated from lymphoma, melanoma and carcinomas of various organs. Alveolar soft part sarcoma (ASPS) is a very rare neoplasm that is usually found in the lower extremities. Lungs are the common site of dissemination and may represent initial manifestation of disease. We report a clinically unsuspected case of ASPS presenting as a breast metastasis in a 25-year-old woman. The patient’s medical history was notable for a thyroid cancer treated by surgery and radioiodine ablation 2 years ago. Core needle biopsy of slowly growing breast mass yielded polygonal cells with abundant eosinophilic cytoplasm arranged into solid pattern. Differential diagnosis between apocrine cell carcinoma, paraganglioma, granular cell tumor, neuroendocrine carcinoma, ASPS and metastatic hepatocellular and renal cell carcinoma was rendered by immunohistochemistry. Strong nuclear TFE3 immunoreactivity confirmed a diagnosis of ASPS. Retrospectively a primary tumor was found in the thigh. Most likely, ASPS and thyroid cancer in the patient were growing synchronously and independently.     

Fine-needle aspiration cytology of alveolar soft-part sarcoma

Alveolar soft-part sarcoma (ASPS) is a rare soft-tissue tumor. Few cases have been reported in the aspiration cytology literature. We discuss the fine-needle aspiration (FNA) cytologic features of ASPS in four patients. The smears were characterized by single cells and clusters of cells associated with thin-walled vasculature, resulting in a distinct pseudoalveolar pattern. The cells had abundant granular cytoplasm and large round nuclei with prominent central nucleoli. Binucleated and occasional multinucleated cells were present. Numerous stripped tumor nuclei were a consistent feature. Periodic acid-Schiff (PAS)-positive diastase-resistant granules were demonstrable within the intact and fragmented cytoplasm. Electron microscopy of aspirated material identified granules and crystals with the characteristic lattice pattern. To conclude, the FNA cytologic features of ASPS are characteristic. Confirmation by special stains and electron microscopy of FNA material is possible. The differential diagnostic considerations include renal cell carcinoma, paraganglioma, granular cell tumor, clear cell sarcoma, and epithelioid sarcoma.     

Primary alveolar soft part sarcoma of the stomach: a case report and review

Alveolar soft part sarcoma (ASPS) is a rare tumor typically located in skeletal muscles and muscolofascial planes. Isolated cases of ASPS have been described as arising in the viscera. We report a mesenchymal tumor of the stomach in a 54-year-old Italian woman without evidence of primary neoplasm elsewhere ten years following the initial diagnosis. The histologic, histochemical, immunohistochemical, and electron microscopic findings were all consistent with the diagnosis of ASPS and allowed differentiating it from morphologically similar and more common tumors, such as metastatic renal cell carcinoma and paraganglioma. The patient is alive and well ten years following the initial presentation.     

应用逆转录-聚合酶链反应检测石蜡包埋腺泡状软组织肉瘤中ASPL-TFE3融合基因的表达

目的 探讨石蜡包埋腺泡状软组织肉瘤中t(X：17)(p11．2：q25)染色体易位融合基因ASPL-TFE3 mRNA表达的意义。方法 收集以4％甲醛固定、石蜡包埋腺泡状软组织肉瘤标本8例,运用逆转录一聚合酶链反应(RT-PCR)方法检测ASPL-TFE3融合基因mRNA表达,以管家基因β-肌动蛋白(actin)作为内对照检测mRNA质量。另以腺泡状横纹肌肉瘤6例,肾细胞癌6例,副神经节瘤2例,颗粒细胞瘤1例作为对照。结果8例腺泡状软组织肉瘤中4例检测到ASPL-TFE32型融合基因mRNA的表达,2例检测出ASPL-TFE31型融合基因mRNA的表达,余2例β-actin和ASPL-TFE3的检测均为阴性。对照组未检出ASPL-TFE3融合基因,其中6例腺泡型横纹肌肉瘤中4例有PAX3／7-FKHR融合基因的表达。结论 石蜡包埋组织中ASPL-TFE3融合基因表达可作为腺泡状软组织肉瘤诊断和鉴别诊断的分子指标,并有助于其分子发生机制的回顾性研究。     

Epithelioid Monophasic Synovial Sarcoma

A 47-year-old man presented with a soft tissue mass of the distal right thigh near the knee. The tumor was highly vascular with epithelioid tumor cells growing in a peritheliomatous pattern, suggesting a soft tissue glomus tumor. Yet many tumor cells contained hemosiderin pigment and formed papillary structures suggestive of pigmented villonodular synovitis. Tumor cells were cytologically bland, and there was minimal mitotic activity. The tumor cells were strongly immunoreactive for cytokeratin, however, and contained true desmosomes, gland lumina, microvilli, tonofilaments, and well-developed basal lamina. These findings plus the absence perinuclear aggregates of intermediate filaments rule out malignant rhabdoid tumor and epithelioid sarcoma. Also, magnetic resonance imaging revealed no other lesions to suggest metastatic carcinoma. Thus this tumor appears to be a predominantly epithelioid form of monophasic synovial sarcoma. Recognition of this variant of synovial sarcoma is important for prognostication and therapeutic decision making because some studies indicate that this variant of synovial sarcoma follows a relatively benign clinical course.