Fibromatosis-like carcinoma of the breast
One of the challenges in breast cancer diagnosis is to distinguish between benign breast changes and potentially malignant neoplasms. Mammography and ultrasound can usually give a good indication if a lesion is clearly malignant (odd shaped, with ill-defined or infiltrative borders), but other lesions which may still seem ‘probably benign‘ on mammography and require evaluation by a biopsy and histological analysis.
This page is getting pretty out-dated, however it does not mean that you should quit using it… Although I have created a newer version with more up-to-date information on Fibromatosis Carcinoma of the Breast, I would totally still recommend it.
This is the case when the cancer physicians attempt to distinguish between a breast fibromatosis, which is benign, and certain types of metaplastic breast carcinomas, in particular spindle cell breast carcinoma, which have very similar clinical and microscopic appearances. A “fibromatosis-like” carcinoma of the breast is basically a sub-classification of breast spindle cell carcinoma which has a dominant fibromatosis-like phenotype, remembering that a spindle cell breast carcinoma is itself a sub-type of metaplastic breast carcinoma.
A breast spindle cell carcinoma can include a wide spectrum of lesions with various histomorphologic and nuclear features that can range from highly malignant to mildly atypical. These ‘mildly atypical‘ features might be suggestive of a very low grade carcinoma, or maybe a benign myofibroblastic breast tumor of breast fibromatosis. So, it is not the easiest diagnosis to make, and requires a thorough histological workup.
Fibromatosis-like breast carcinomas have few epithelial cell components
A fibromatosis-like variant of a metaplastic/spindle-cell tumor will usually only have a very small amount of epithelial cell elements, but it is still an important distinction to make. The fibromatosis-like breast carcinoma has a higher likelihood of local recurrence rather than distant metastasis, which is somewhat different than metaplastic breast carcinomas taken as a whole.
Clinical presentation of fibromatosis-like breast carcinomas
Breast fibromatosis-like carcinoma tends to develop in women in their 50’s to 80’s, with an average age of presentation of about 65, so we can generalize that it is more common in older women. They tend to present as an average size tumor (2 to 3 cm) and usually have grossly well defined borders, but often with infiltrative segments (though these are often only seen microscopically).
Fibromatosis like carcinoma more of a breast ‘tumor’ than a carcinoma?
Some recent studies have suggested that this fibromatosis-like variant of spindle cell breast carcinoma ought to be labelled as a breast ‘tumor‘ and not a ‘carcinoma‘. The reason for this is that fibromatosis like breast carcinomas really have very little propensity for distant metastasis. However, there is no wide-ranging and consistent evidence of this, and the risks of under-evaluation of the tumor can be quite severe.
The key factor seems to be certain features in the histological analysis, in particular the presence of high amounts of cytokeratins along with smooth muscle actin, which seem to be associated with a higher rate of metastasis. The “CK” elements are associated with the malignant epithelial elements of the tumor, so one has to keep an eye on the relative amounts of CK.
Histological features of fibromatosis-like breast carcinoma
As a fibromatosis-like breast carcinoma is a rare sub-type of metaplastic breast cancer, this implies that there will be a combination of epithelial cells involved along with myoepithelial cells, and possible other cells in a ‘transitional-state‘ in between the two.
In a fibromatosis-like breast carcinoma the predominant cell-type will be the myoepithelial-cell variety (appearing as spindle cells) with a very small amount, most likely less than 5% , of epithelial cell involvement. In fact, it is malignancy in the epithelial cell elements which confirm a diagosis of ‘carcinoma‘ (cancer of epithelial cells).
Most fibromatosis-like breast tumors will show a dominant fibromatosis-like or myofibroblastic-like growth pattern, and often with prominent collagenization. These areas of spindle cells interspersed with areas of ‘keloid-like‘ collage will be quite reminiscent of the appearance of a benign breast fibromatosis.
One will often see a small group of epithelioid cells which seem to ‘merge‘ into spindle cell areas. One might also encounter prominent areas of sclerosis reminiscent of keloid formation in a fibromatosis-like breast carcinoma. Breast fibromatosis-like tumors will quite often reveal a certain degree of inflammatory infiltrate as well.
Fibromatosis-like breast cancers tend to present with ‘low grade’ cells
A fibromatosis-like breast carcinoma will often seen to be infiltrating into the surrounding tissue and fat to a degree. It will mostly consist of spindle cells with a relatively bland morphology, often arranged in a storiform, fascicular, or simply random fashion. Mitotic activity will generally be very low.
Cytologic examination will usually show smears of low cellularity with most epithelioid cells lying in clusters, and typically having a round or oval shape, with some rare cells having a ‘spindle‘ shape. There may be mild atypica among epithelioid cells, but if present it will be quite inconspicuous. Generally, all nuclear features are of ‘low grade‘ morphology.
Immunohistochemical aspects of fibromatosis-like breast carcinomas
The main distinguishing immunohistochemical feature of fibromatosis-like carcinomas of the breast is the presence of cytokeratin-positive cells, which occurs in virtually all cases. Cytokeratin-positive cells will usually appear as cords or sheets of polygonal cells; one rarely encounters these cells in isolation. Many of the cells in a fibromatosis-like breast tumor will also be strongly positive for smooth muscle actin (SMA), but this is usually confined to cells which are cytokeratin-negative.
Cytokeratin markers (CK, HMWCK, anc CK7) are all markers for epithelial cell involvement, while vimentin, SMA, and p63 will be markers for cells of a myoepithelial origin (HMWCK refers to ‘high molecular weight‘ cytokeratin).
Fibromatosis-like breast tumors are often triple negative
Fibromatosis-like breast carcinomas tend to be negative for estrogen and progesterone receptors, and also negative for HER-2/neu proteins. Ki-67 expression might be noted in fibromatosis-like carcinomas, but usually in fewer than 5% of tumor cells. (Ki-67 is considered to be a marker for a highly proliferative situation) Fibromatosis-like breast tumor cells are also generally negative for gross cystic disease fluid protein.
Treatment and prognosis for breast fibromatosis-like carcinoma
The main concern with fibromatosis-like carcinoma of the breast is that it may be under-diagnosed as benign fibromatosis or nodular fasciitis, and left untreated or inadequately treated. The use of thorough immunohistochemical studies, especially the presence and degree of cytokeratins and smooth muscle actin, can give a better idea of the potentially malignant nature of the tumor.
Fibromatosis-like breast tumors are usually treated either by local excision, preferably a wide local excision, or by modified radical mastectomy. Radiotherapy following surgery is a likely course of action, and follow-ups examination with sentinel-node biopsy might also be recommended.
Most women with fibromatosis-like breast cancers are curable
If a fibromatosis-like breast carcinoma has metastasized, which is uncommon, then the prognosis tends to be rather poor. This is why one has to be very careful with both the diagnosis and follow-up of a fibromatosis-like breast carcinoma. It can have a deceptively benign appearance, but it truly is a malignant process with a potentially highly aggressive behavior.
However, most patients with fibromatosis-like carcinoma of the breast, when treated with a wide excisional biopsy, are cured, with only a small percentage experiencing local recurrence, and virtually no evidence of distant or regional metastasis. So, if a fibromatosis-like breast carcinoma is properly identified and treated aggressively with a wide local excision or possibly a mastectomy, then it is highly likely that the breast cancer is cured and the outlook is highly positive.
For further reading, I suggest you visit this page that has information on Fibromatosis of the breast.
Below is a few common Q&A on this topic:
- What is breast fibromatosis treatment? A wide local excision with clear margins remains the treatment of choice. Recurrence rates can be fairly high, especially in those with positive margins. Recurrence is less likely to happen if a wide excision is performs and resection margins are made. And recurrences are often treated with radical excision, as the primary tumor.
- What are the breast fibromatosis symptoms? Skin tethering, tender, firm, and solid-feeling.
- What is breast fibromatosis like on MRI? It is seen an irregular breast mass and MRI is often useful to show chest wall involvement in selected cases prior to surgical planning.
- What are fibromatosis causes? It remains unclear. But in some types of fibromatosis, such as desmoid tumors, it is thought that the condition may be in relation to trauma, hormonal factors, or have a genetic association. It has been reported to occur after breast implants.
- What are fibromatosis subtypes? Juvenile fibromatosis, fibromatosis colli, infantile digital fibromatosis, infantile myofibromatosis, ipofibromatosis, fibromatosis hyalinica multiplex, plantar fibromatosis, penile fibromatosis (Peyronie’s disease), and palmar fibromatosis (Dupuytren’s contracture).
- Survival rate? Because fibromatosis is not cancer, it has 100% survival.
References
- Sneige N, Yaziji H, Mandavilli SR, Perez ER, Ordonez NG, Gown AM, Ayala A. Low-grade (fibromatosis-like) spindle cell carcinoma of the breast. Am J Surg Pathol. 2001 Aug;25(8):1009-16.
- Kinkor Z, Svitáková I, Ryska A, Kodet R, Hrabal P.Metaplastic spindle-cell (fibromatosis-like) carcinoma of the breast–report of 4 cases. Cesk Patol. 2002 Oct;38(4):164-8.
- Torngren S, Frisell J, Nilsson R, Wiege M: Nodular fasciitis and fibromatosis of the female breast simulating breast cancer. Case reports. Eur J Surg 1991 , 157:155-158.
- Rekhi B, Shet TM, Badwe RA, Chinoy RF. Fibromatosis-like carcinoma-an unusual phenotype of a metaplastic breast tumor associated with a micropapilloma. World J Surg Oncol. 2007 Feb 27;5:24.
- Torngren S, Frisell J, Nilsson R, Wiege M: Nodular fasciitis and fibromatosis of the female breast simulating breast cancer. Case reports. Eur J Surg 1991 , 157:155-158.
- Page DL, Anderson TJ: Uncommon types of invasive carcinoma: Diagnostic histopathology of the breast. Edinburgh, Scotland: Churchill Livingstone; 1987:236-252.
- Gersell DJ, Katzenstein ALA: Spindle cell carcinoma of the breast. A clinicopathologic and ultrastructural study. Hum Pathol 1981 , 12:550-561.
- Kontonegros G, Papamichalis G, Bouropouplou V: Fibroblastic lesion of the breast exhibiting features of nodular fasciitis. Arch Anat Cytol Pathol 1988 , 36:113-115.
- Gobbi H, Simpson JF, Borowsky A, Jensen RA, Page DL: Metaplastic breast tumors with a dominant fibromatosis-like phenotype have a high risk of local recurrence. Cancer 1999 , 85:2170-2182.
- Jarboe, E., Layfield, L., Collins, B. Fibromatosislike Metaplastic Carcinoma of the Breast as a Diagnostic Pitfall for Fine Needle Aspiration Cytology: A Case Report. Acta Cytologica, (sept. 2010)
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