Table of Contents
Definition / general | Radiology images | Prognostic factors | Case reports | Clinical images | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Positive stains | Electron microscopy description | Electron microscopy images | Molecular / cytogenetics descriptionCite this page: Shankar V. Alveolar soft part sarcoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/softtissuealveolarsoft.html. Accessed January 22nd, 2021.
Definition / general
- Rare tumor of deep soft tissue characterized by well defined nests of cells separated by fibrous stroma
- 0.5 - 1.0% of all soft tissue tumors
- Deep soft tissue of oral cavity, pharynx, mediastinum, thigh / leg
- Usually young females
- Highly malignant, although clinical course is slow / indolent
- Metastases up to 30 years later to veins, lungs, other
- Lung metastases may be presenting feature
Prognostic factors
- Size, presence of 17q25 abnormality, AJCC stage, age
Case reports
- 5 year old boy with orbital tumor (Afr J Paediatr Surg 2011;8:82)
- 18 year old woman with primary alveolar soft part sarcoma of tongue and CNS metastases (Case of the Week #222)
- 25 year old man with tumor of tongue (Indian J Pathol Microbiol 2011;54:581)
- 44 year old man with metastatic nodule on nose (Indian J Dermatol Venereol Leprol 2012;78:666)
Clinical images
Gross description
- Well circumscribed, large, gray - yellow, hemorrhage, necrosis
- Size ranges from 2 - 14 cm
Microscopic (histologic) description
- Well defined nests of cells separated by fibrous stroma
- Alveolar pattern if cells discohesive
- Composed of large polygonal cells with granular eosinophilic cytoplasm, vesicular nuclei, prominent nucleoli
- Vascular invasion common; also characteristic rod-shaped crystalloids
- No / rare mitotic figures, minimal pleomorphism
Microscopic (histologic) images
Contributed by Andrey Bychkov, M.D., Ph.D.
Contributed by Mark R. Wick, M.D.
Case #222
Images hosted on other servers:
Cytology description
- Strong similarity to renal cell carcinoma, clear cell type
- Variably cellular smears composed of large cells with an abundant finely granular or vacuolated cytoplasm, markedly enlarged nuclei / nucleoli, and bare nuclei (Cancer 2009;117:500)
Cytology images
Positive stains
- PAS+ diastase resistant needle-like structures, MyoD1 (cytoplasmic only), TFE3 (Diagn Mol Pathol 2008;17:245)
Electron microscopy description
- Membrane bound crystals with periodicity of 58 - 100 nm and cross grid pattern
- Numerous electron dense vesicles near Golgi
- Smooth tubular aggregates associated with plasmalemmal invaginations
- No features of skeletal muscle differentiation
Molecular / cytogenetics description
- Changes in #1, 5, 13, 17