Soft tissue
Uncertain differentiation
Alveolar soft part sarcoma
Author: Vijay Shankar, M.D.
Topic Completed: 1 November 2012
Minor changes: 7 December 2020
Copyright: 2002-2021, PathologyOutlines.com, Inc.
PubMed Search: Alveolar soft part sarcoma [title]
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 May 6th, 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
Radiology images
Contributed by Mark R. Wick, M.D.
CT scan, orbital
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
Contributed by Mark R. Wick, M.D.
Orbital
Images hosted on other servers:
Orbital tumor
Tongue
Nose and thigh
Gross description
- Well circumscribed, large, gray - yellow, hemorrhage, necrosis
- Size ranges from 2 - 14 cm
Gross images
Contributed by Mark R. Wick, M.D.
Various images
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.
Cytoplasmic vacuolation
cells with abundant
acidophilic granular cytoplasm
Positive nuclear staining for TFE3 is diagnostic of ASPS
Contributed by Mark R. Wick, M.D.
Alveolar soft part sarcoma
PAS
TFE3 stain
Case #222
MyoD1
PAS-D
TFE3
Vimentin
Images hosted on other servers:
Tongue
Lobular structure
Loss of cohesion in cell lobules
Thigh mass
H&E
S100
PAS+
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
Contributed by Mark R. Wick, M.D.
FNA
Images hosted on other servers:
Figures 1 - 6
Metastatic renal cell carcinoma
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
Electron microscopy images
Contributed by Mark R. Wick, M.D.
EM
Molecular / cytogenetics description
- Changes in #1, 5, 13, 17
