Sebaceous Carcinoma of the Breast
A breast sebaceous carcinoma is essentially a skin cancer that happens to be growing on the skin of the breast. Sebaceous carcinoma is not usually related to the conventional ductal carcinomas characteristic of breast cancer.
However, it is also possible for women to have an invasive ductal carcinoma that has many features, or a certain percentage of the tumor, that has commonalities with sebaceous gland carcinomas of the skin. Sebaceous carcinoma of the breast is VERY rare.
I just want to let you know that I have created a newer version of this page with more up-to-date information on rare types of breast cancer. However, this page still has great material, and I would still recommend on using it as well.
So, sebaceous carcinoma is a distinctive type of breast cancer that is characterized by unequivocal morphologic differentiation towards sebaceous epithelium or sebocytes. (Sebocytes are epithelial cells that originate from a basal cell layer at the periphery of the gland).
Sebaceous breast cancer cells resemble skin sebaceous glands
Sebaceous carcinomas will often contain many lobules and nests of clear cells that closely resemble the sebaceous glands of the skin.
This type of breast cancer can also sometimes develop within an intraductal breast papilloma.
Sebaceous breast cancers tend to be of a low grade
Specialists tend to consider sebaceous breast carcinomas to be a ‘low grade‘ tumor. Indeed, they actually most commonly develop in and around the eyelids.
If a sebaceous carcinoma of the breast show multicentricity, poor differentiation and infiltrative growth, then the tumor may have a worse prognosis. Most patients who develop sebaceous carcinoma of the breast do so in their 60’s or 70’s, though it can sometimes develops a little earlier.
Clinical presentation of sebaceous carcinoma of the breast
A sebaceous carcinoma of the breast will usually present as a small mass. However, there is always a risk that doctors will dismiss the lesion as something benign, like a common skin lesion.
This is because sebaceous breast carcinomas are not always easy to see on a screening mammogram either. The size of a sebaceous breast tumor will often range from 1 cm to 4 cm on initial diagnosis.
A mammogram of a breast sebaceous carcinoma will usually reveal pleomorphic calcifications, and these lesions are often well circumscribed.
Histological features common with breast sebaceous carcinomas
Well-defined solid sheets or lobules of atypical epithelial cells usually define sebaceous carcinoma of the breast. These cells also frequently include many large pale or clear cells, often with ‘scalloped’ nuclei.
The cytoplasm is usually coarsely vacuolated , and abundant lipid droplets can often be identified in the cytoplasm with oil-red-O staining.
Important differentiation from squamous and basal cell breast carcinomas
The clear cells of sebaceous carcinoma of the breast tend to be negative with alcian blue and periodic acid-Schiff and staining.
The atypical epithelial tumor cells tend to test positive for the epithelial membrane antigen, human milk fat globules subclass 1, human milk fat globules subclass 2 and Leu M1.
Breast sebaceous tumor cells tend not to express carcinoembryonic antigen, breast carcinoma associated antigen, S-100 protein, gross cystic disease fluid protein-15 or Dako M1.
Sebaceous breast carcinomas are also frequently reactive for Cam 5.2, and BRST-1. This can be an important means of differentiating sebaceous gland breast carcinomas from squamous cell breast carcinomas and breast basal cell carcinomas.
Sebaceous carcinoma of the breast is quite often positive for cytokeratin, but not for vementin and carcinoembryonic antigen. Most of the tumor cell nuclei in sebaceous breast carcinoma will be reactive for antibodies to progesterone and estrogen receptors, but not for the HER2/neu protein.
Outlook and treatment for breast sebaceous carcinoma
Medics and specialists do not know a great deal about sebaceous carcinomas of the breast because it is so very rare.
However, if we take the example of a skin sebaceous carcinoma, then clearly, sebaceous breast carcinoma should be considered an aggressive cancer.
Sebaceous cell breast tumors will likely exhibit an aggressive clinical course, with a significant tendency for both local recurrence and distant metastasis.
Surgery followed by chemotherapy is common
Surgeons will normally completely excise a sebaceous carcinoma of the breast. A modified mastectomy is sometimes necessary, and depending on the situation an axillary lymph node dissection might be prudent.
Follow-up should be frequent in order to look for possible metastasis. Physicians will commonly treat sebaceous carcinoma of the breast with chemical agents such as interferon with retinoids.
Another useful treatment for sebaceous carcinoma of the breast is radiation therapy . However, without the full surgical removal of the carcinoma these attempts tend not to be that successful.
The main concern with sebaceous breast cancer is a delay in diagnosis
The main factor affecting the outcome of sebaceous cell cancer of the breast will likely be an unfortunate delay in proper diagnosis and treatment.
Sometimes doctors initially dismiss the lesion as a mild skin disease. However, if there is any doubt it is very important to obtain a biopsy.
Studies estimate that the rate of local recurrence for breast sebaceous carcinoma can be as high as the 30% range. Furthermore local recurrence is likely to happen within the first five years following treatment.
If there is no regional metastasis and no local or regional progression of the disease, then the outlook for breast sebaceous carcinoma is good.
If a patient with sebaceous breast carcinoma has experienced metastatic disease, then the chances of surviving beyond five years are unfortunately probably in the 50% range only.
For further reading, I suggest you visit this page which has a little bit of information on sebaceous cysts of the breast, and this page as well for pure squamous cell carcinoma within the breast.
- Alzaraa A, Ghafoor I, Yates A, Dhebri A. (2008) Sebaceous carcinoma of the skin of the breast: a case report. J Med Case Reports. 2008 Aug 15;2:276. https://jmedicalcasereports.biomedcentral.com/articles/10.1186/1752-1947-2-276
- Kinkor Z, Meciarová I, Havlícek F. (2010) Primary sebaceous carcinoma of the breast; three casuistic reports. Ceska Gynekol. 2010 Feb;75(1):50-3. https://www.ncbi.nlm.nih.gov/pubmed/20437837
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