Breast
Sarcoma
Stromal sarcoma
Author: Emily S. Reisenbichler, M.D.
Topic Completed: 1 March 2017
Minor changes: 21 June 2020
Copyright: 2002-2019, PathologyOutlines.com, Inc.
PubMed Search: stromal sarcoma breast
Table of Contents
Definition / general | Essential features | Clinical features | Prognostic factors | Case reports | Treatment | Clinical images | Gross description | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Electron microscopy description | Differential diagnosisCite this page: Reisenbichler ES. Stromal sarcoma. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/breastmalignantstromalsarcoma.html. Accessed January 22nd, 2021.
Definition / general
- Most recent WHO edition (2012) reclassified as "periductal stromal tumour" as the preferred "neutral term" in the family of fibroepithelial tumor
- Stromal proliferation around open, benign tubules
Essential features
- Considered a type of fibroepithelial tumor lesion with stromal proliferation around benign tubules
- Lacks the defined tumor borders and compressed tubules of fibroadenoma and leaf-like architecture of phyllodes tumor
- Must demonstrate stromal atypia and mitotic activity to be considered a sarcoma
Clinical features
- Occurs in peri- and postmenopausal women (median 55.3 years), approximately 10 years older than the median phyllodes presentation (Am J Surg Pathol 2003;27:343)
- Variable clinical presentation
Prognostic factors
- Good overall prognosis
- Low recurrence risk, ~10% (Am J Surg Pathol 2003;27:343)
Case reports
- 14 year old boy with periductal stromal sarcoma (J Med Case Rep 2011;5:249)
- 35 year old woman with periductal stromal sarcoma of the breast with liposarcomatous differentiation (Int J Surg Pathol 2015;23:221)
- 43 year old woman with periductal stroma sarcoma 5 months following excision of a phyllodes tumor (Oncol Lett 2014;8:1181)
- 45 year old woman with periductal stromal tumor and synchronous bilateral breast cancer (Anticancer Res 2014;34:3635)
- 52 year old woman with low grade periductal stromal sarcoma of the breast with myxoid features (Pathol Int 2009;59:588)
Treatment
- Given the likely relationship to fibroepithelial lesions, treatment is similar to that of phyllodes tumor
- Wide excision with negative margins
- As with primary breast sarcoma, assessment of axillary sentinel lymph nodes is not necessary
- Adjuvant chemotherapy and radiation are not typically warranted unless presenting with a higher grade sarcomatous component
Clinical images
Contributed by Dr. Mark R. Wick
Mammogram
Gross description
- Ill defined nodular mass (mean 3 cm)
Microscopic (histologic) description
- Increased stromal cellularity of spindled stroma surrounding, or "cuffing" benign ducts in a pericanalicular pattern
- Involved tubules and ducts are not malignant
- Stromal cells demonstrate at least moderate cytologic atypia and mitotic activity
- Infiltrative and often multinodular microscopic border
- May be seen with areas of angiosarcomatous (Am J Surg Pathol 2003;27:343) or liposarcomatous components (Int J Surg Pathol 2015;23:221)
Microscopic (histologic) images
Contributed by Emily S. Reisenbichler, M.D.
Cytologically atypical spindled cells cuffing benign ducts
Numerous mitoses present in
cytologically atypical stromal
cells adjacent to ducts
Contributed by Dr. Mark R. Wick
Various images
Images hosted on other servers:
H&E, periductal proliferation
H&E, regular epithelial structures
Atypical cells showing mitosis
CD34+
Contributed by Semir Vranic, M.D.
H&E, 5x
H&E, 10x
H&E, 10x
H&E, 10x
Tumor cells negative for
AE1 / AE3, CK7, CD34, S100,
beta-catenin, and desmin while
SMA was focally positive
Negative stains
Electron microscopy description
- Undifferentiated mesenchymal cell features such as free ribosomes and irregular profiles of rough endoplasmic reticulum
- Fibroblastic differentiation such as well organized dilated rough endoplasmic reticulum, Golgi complexes, cytoplasmic filaments and pericellular collagen (Cancer 1979;43:209)
Differential diagnosis
- Periductal stromal hyperplasia: nodular growth, lacks the cytologic atypia and mitoses typical of a stromal sarcoma (0 - 2 mitoses per 10 high power fields)
- Phyllodes tumor: has a more defined tumor border with compression and distortion of ductal elements causing a "leaf-like" architecture; abundant stromal overgrowth of intralobular stroma, not limited only to periductal areas
