Advertisement
Advertisement
Table of Contents
Definition / general | Epidemiology | Case reports | Treatment | Gross description | Gross images | Microscopic (histologic) description | Microscopic (histologic) images | Cytology description | Cytology images | Positive stains | Negative stains | Molecular / cytogenetics description | Differential diagnosis | Additional referencesCite this page: Small cell carcinoma. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/breastmalignantsmallcell.html. Accessed July 14th, 2017.
Definition / general
- Similar morphologically to lung tumor
- Diagnosis requires exclusion of other primaries or presence of DCIS
- Also known as oat cell carcinomas, high grade neuroendocrine carcinoma, small cell undifferentiated carcinoma
- May arise as variant of metaplastic carcinoma or from multipotential stem cells capable of divergent differentiation (Surg Today 2008;38:734)
- Prognosis may not be as poor as previously thought (Am J Surg Pathol 2000;24:1231)
Epidemiology
- Rare, usually ages 43 - 70 years
Case reports
- 60 year old woman with primary neuroendocrine small cell carcinoma of the breast (Arch Pathol Lab Med 2000;124:296)
- 61 year old woman with E-cadherin negative primary small cell carcinoma of the breast (Am J Clin Pathol 2004;121:117)
- 64 year old woman with small cell neuroendocrine carcinoma of the breast (J Korean Surg Soc 2012;82:116)
- Solid variant of mammary adenoid cystic carcinoma with basaloid features merging with small cell carcinoma (Pathol Res Pract 2005;201:705)
Treatment
- Surgery, possibly chemotherapy (Breast Cancer 2009;16:68)
Gross description
- Mean 3 cm, range 1 - 5 cm
Gross images
Images hosted on PathOut server:
Contributed by Dr. Mark R. Wick
Microscopic (histologic) description
- Typical small cell carcinoma features of scant cytoplasm, small (diameter of three lymphocytes) nuclei with finely granular, evenly distributed chromatin and absent or inconspicuous nucleoli
- Frequent mitoses
- Frequent crush artifact or nuclear streaming
- Infiltrative borders, lymphatic tumor emboli and necrosis
- Associated with invasive poorly differentiated carcinoma and lobular carcinoma
- Associated with small cell in situ carcinoma and high grade DCIS
Microscopic (histologic) images
Images hosted on PathOut server:
Contributed by Dr. Mark R. Wick
Images hosted on other servers:
Chromogranin+
Neurone specific enolase+
H&E, p63, synaptophysin, TTF1
Classic features
Lung:
Classic features
Flow, H&E and stains (site unknown)
Cytology description
- Resembles small cell carcinoma of lung (Breast Cancer 2007;14:414)
Cytology images
Images hosted on PathOut server:
FNAB, contributed by Dr. Mark R. Wick
Images hosted on other servers:
Clusters of monotonous neoplastic cells
Positive stains
- CK7, E-cadherin (100%, Am J Surg Pathol 2001;25:831)
- ER or PR (35 - 50%, Semin Oncol 2007;34:64)
- bcl2, TTF1 (20%)
- Variable neuroendocrine staining (neuron specific enolase, synaptophysin, chromogranin)
- May have basal-like phenotype due to expression of EGFR and basal-type keratins (Int J Surg Pathol 2009;17:368), or "triple negative" pattern (Med Mol Morphol 2009;42:58)
Molecular / cytogenetics description
- Small study shows similar genetic changes as both invasive ductal carcinoma and lung small cell carcinoma (Hum Pathol 2001;32:753)
Differential diagnosis
- Invasive lobular carcinoma: single file or targetoid patterns, cells have low grade features with occasional intracytoplasmic vacuoles, no nuclear molding and are E-cadherin negative
- Metastatic tumor from lung or elsewhere: see Diagn Cytopathol 2009;37:208
Additional references
Advertisement
