Soft tissue
Uncertain differentiation
Alveolar soft part sarcoma


Topic Completed: 1 November 2012

Minor changes: 17 September 2020

Copyright: 2002-2020, PathologyOutlines.com, Inc.

PubMed Search: Alveolar soft part sarcoma [title]

Vijay Shankar, M.D.
Page views in 2019: 14,085
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Cite this page: Shankar V. Alveolar soft part sarcoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/softtissuealveolarsoft.html. Accessed October 29th, 2020.
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
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

Large, rounded, polygonal
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
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
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