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
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.
Images hosted on other servers:
Contributed by Semir Vranic, M.D.
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