Cytopathology of alveolar soft part sarcoma: a report of 10 cases

Alveolar soft part sarcoma : a case report and review of literature

Alveolar soft part sarcoma (ASPS) is a rarely diagnosed tumor of deep soft tissue origin. This tumor is more common in adolescents and young adults and has a slowly progressive clinical course which often leads to delayed diagnosis and treatment. It is highly vascular, can be confused with other entities like hemangiomas and arteriovenous malformations clinically and radiologically and thus challenging to report on fine needle aspiration cytology (FNAC). Diagnosing the tumor is difficult on cytology, so knowledge of this entity and the differentials with its morphological mimics on cytology is required for timely diagnosis and early management of the patient. We report a case of ASPS in a young female who presented with a large painless swelling in the thigh, diagnosed on cytology combined with ancillary testing with immunohistochemical markers.

Revisiting cytomorphology, including unusual features and clinical scenarios of 8 cases of alveolar soft part sarcoma with TFE3 immunohistochemical staining in 7 cases

OBJECTIVES

To present a comprehensive analysis of cytomorphological features, including clinical scenarios, for 8 cases (4 males, 4 females, aged 17-39 years, average = 28.5) of, retrospectively diagnosed alveolar soft part sarcoma (ASPS), with TFE3 immunostaining in 7 cases.

METHODS

Conventional Papanicolaou and May Grunwald-Giemsa (MGG) stained smears and corresponding tissue sections were critically reviewed. Fine needle aspiration cytology was performed for primary diagnosis in 6 cases and for metastatic lesions in 2 cases. TFE3 and other immunohistochemical stains were tested using polymer detection technique.

RESULTS

Tumour sites were thigh (n = 6), shoulder (1) and neck (1). Tumour size (n = 6) varied from 5 to 14.5 cm (average = 7.2). Seven out of 8 cases were correctly diagnosed on cytosmears. The smears were mostly hypercellular (5), composed of cohesive clusters (8), including cell balls and pseudopapillae (3) and singly scattered cells (8). Tumour cells were round to oval, containing central to eccentric nuclei (8), abundant granular (8) to finely vacuolated (7) cytoplasm that was ill- to well-defined, intracytoplasmic rod-like or needle-shaped crystals (3) and prominent nucleoli (8), Additionally, there were binucleated cells (7), multinucleation (2), intracytoplasmic inclusions (3), intranuclear inclusions (2), intercellular stroma (5) and bare nuclei (8). Immunohistochemically, 7/8 tumours were positive for TFE3.

CONCLUSIONS

This constitutes the largest series describing cytomorphological spectrum of ASPS with TFE3 immunostaining results. Frequently observed features and rod-like/needle-shaped crystals on MGG smears, can help to differentiate ASPS from its mimics. TFE3 immunostaining aids in substantiating diagnoses, in an appropriate clinicoradiological context.

Soft tissue tumor diagnosis: A three prong approach utilizing pattern analysis, immunocytochemistry, and molecular diagnostics

Tissue diagnosis of a soft tissue neoplasm is of paramount importance for the development of an appropriate treatment plan. Biopsy technique including approach and biopsy method is important to the success of diagnosis and subsequent treatment. Histologic and cytologic diagnoses are difficult and complicated by the large number of soft tissue lesions described, distinctly different biopotential for morphologically similar lesions, often small biopsy specimen size, and the generally limited experience many pathologists have in the diagnosis of soft tissue neoplasms. While utilized less frequently than core-needle biopsies, fine-needle aspiration is a valuable initial approach for the classification of soft tissue neoplasms. The combination of pattern based morphologic analysis, immunohistochemistry, and molecular diagnostics represents a utilitarian and generally successful approach for the diagnosis of soft tissue lesions.

Alveolar soft-part sarcoma of the oral cavity: A review of literature

An alveolar soft-part sarcoma is a malignant neoplasm primarily affecting the soft tissues of head and neck. The aim of the present review is to systematically present the demographic and clinico-pathological data of articles published in the English medical literature. A comprehensive search of the databases (PubMed, Medline, SCOPUS, Web of Science, and Google Scholar) along with cross references to the published articles on alveolar soft-part sarcoma for eligible studies/case reports published since 1957 till date was done to retrieve the data. A total of 74 cases were identified and analyzed from 42 papers published in the English medical literature. All the clinical, radiographic, and prognostic features were analyzed and presented along with the treatment strategies. Alveolar soft-part sarcoma is a rare and aggressive malignancy of uncertain histologic origin with a propensity for vascular invasion and distant metastasis. This neoplasm requires careful clinical, radiographic, and histopathologic evaluation to reach to the correct diagnosis.

Prominent Intracytoplasmic Crystals in Alveolar Soft Part Sarcoma (ASPS): An Aid in Cytological Diagnosis

Alveolar soft part sarcoma (ASPS) is a rare neoplasm of unknown histogenesis with poor prognosis. Due to the epithelioid appearance of the neoplastic cells, ASPS may resemble many neoplastic conditions, such as metastatic epithelial cell tumours with clear cell change, metastatic renal cell carcinoma, granular cell tumour, epithelioid sarcoma, malignant melanoma and even paragangliomas. Presence of abundant, rod like crystals in the cytoplasm of tumour cells is an important finding characteristic of this tumour, which helps in differentiating it from the other entities. The case study highlights the importance of correlating cytological features that help in reaching the diagnosis such as the background, cell morphology and presence of characteristic rod shaped crystals as immunohistochemical studies are often non-conclusive. The case also is unique as it demonstrates presence of intra-cytoplamic crystals in such abundance.

Alveolar soft part sarcoma-radiologic patterns in children and adolescents

BACKGROUND

Alveolar soft part sarcoma is a rare but highly malignant tumour and little is known about its radiologic pattern in children.

OBJECTIVE

To describe the radiologic features of alveolar soft part sarcoma in children and adolescents.

MATERIALS AND METHODS

We retrospectively analysed the clinical and imaging data of six children age 7-17 years at diagnosis, with histologically or genetically proven alveolar soft part sarcoma.

RESULTS

The tumours were located deep within muscles of the limbs (n = 4), in chest wall muscle (n = 1) and in the orbit (n = 1). High-flow feeding arteries, large drainage veins and intense enhancement were consistent findings by all imaging modalities. At MRI, all tumours demonstrated high signal intensity on T2-weighted images and high or iso-intense signal on T1-W imaging compared to muscle. In tumours larger than 70 mm in one dimension (n = 3/6), large vessels converging toward the tumour centre led to a highly vascularised central stellar area pattern. Five children demonstrated synchronous (n = 4/5) and metachronous (n = 1/5) lung metastases.

CONCLUSION

Alveolar soft part sarcoma should be suggested when a highly vascularised, intramuscular mass demonstrating large feeding and drainage vessels converging toward a central stellar area is seen in children, especially if synchronous lung metastases are present.

Alveolar soft-part sarcoma of the masseter and mandibular ramus: Report of a case and review of the literature

Alveolar soft-part sarcomas are clinically and morphologically distinct soft-tissue sarcomas, with an unknown histogenesis. When the tumors affect the region of the head and neck, they are often located in the orbit and tongue. We report a case of an alveolar soft-part sarcoma in the left masseter of a 28-year-old female. The patient had chronic pain and paresthesia of her left lower lip. Panoramic radiography and computed tomography showed a well-delimited radiolucent mass in the left ramus. An incisional biopsy was performed, and the sample submitted for histopathological study. The tumor showed positive periodic acid-Schiff diastase-resistant granules. Immunohistochemically, the tumor cells were diffusely positive for myoglobin, and focally positive for actin and desmin.

Cytodiagnosis of alveolar soft part sarcoma: Report of two cases with special emphasis on the first orbital lesion diagnosed by aspiration cytology

Alveolar soft part sarcoma (ASPS) is a rare neoplasm of uncertain cell of origin. Known to occur in adolescents and young adults, this tumor usually involves the muscles and deep soft tissues of the extremities and trunk. Orbital localization is rare and not yet subjected to cytological assessment, as per our literature search. We present here two cases of ASPS diagnosed by aspiration cytology, one in the orbit and the other in the lower extremity. The cells displayed abundant clear to finely vacuolated cytoplasm, often with disrupted margins and flowing of the cytoplasmic material; prominent nucleoli and scattered bare nuclei were also seen in the background. Two close cytological differential diagnoses include metastatic renal cell carcinoma and paraganglioma. Intracytoplasmic periodic acid schiff (PAS) positive, diastase-resistant, needle-shaped crystals and corresponding rhomboid crystals with regular lattice pattern on ultrastructure are the hallmarks of this neoplasm. Due to its slowly progressive clinical course and poor outcome, preoperative diagnosis of ASPS through fine-needle aspiration cytology may be essential for deciding therapy, especially in rare and difficult locations like orbit, where adjuvant radiation may not be possible.