Inflammatory fibroblastic tumor in the breast

An inflammatory fibroblastic tumor is essentially a variation of the uncommon ‘stromal‘ neoplasms of the breast which consist primarily of immature smooth muscle (myo) or fibroblastic (connective tissue) cells, and which can resemble ‘spindle-cell‘ carcinoma in appearance. (If the relative amount of smooth-muscle cells is in majority, the term ‘myofibroblastic‘ breast tumor would be used.)

 
 

Inflammatory myofibroblastic breast tumors are usually considered to be benign, but over time, it has tended more and more to be viewed as a potentially malignant neoplasm. In some cases, constant ‘clonal genetic‘ alterations of cells appear, which has lead to a slightly more suspicious perception of this tumor.

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Fibroblasts and myofibroblasts are somewhat undifferentiated mesenchymal cells which will typically evolve into smooth muscle cells, or connective tissue–fibrous cells. A myofibroblastoma is a tumor composed mostly of a ‘hybrid‘ between fibroblasts and smooth muscle cells, while a solitary fibrous tumor is composed mostly of the fibroblastic cells. An inflammatory myofibroblastic tumor, sometimes also referred to as an ‘inflammatory pseudotumor tumor‘ (IPT), inflammatory myofibrocytic proliferation, or plasma cell pseudotumor, is basically a myofibroblastoma which also contains an inflammatory element. However, the specific diagnosis of inflammatory myofibroblastic tumor is a little bit ambiguous, as the terms if often used for any stromal cell tumor which does not clearly fit the pattern of more established form such as nodular fasciitis and fibromatosis. There also remains lack of clarity as to whether or not an inflammatory myofibroblastic tumor is a true neoplasm, or is the result of some kind of immune system response.

Breast myofibroblastic tumors are rare

Myofibroblastic tumors can happen in many locations in the body, and are very rare in the breast. Most often their development is associated with the lung. When they do occur in the breast, they tend to develop either from the smooth muscle cells in the breast duct lining, for from smooth muscle cells in the lining of blood vessels. Inflammatory myofibroblastic tumors of the breast can occur in either sex, but are slightly more common in women. They also occur in children, more frequently than with adults. The tumor may be accompanied by fever and swelling from increased fluids containing lymphocytes and other antibodies, and anemia.

 
 

Diagnosing an inflammatory myofibroblastic breast tumor

These breast tumors are often discovered by the patients themselves, or may be discovered mammographically. Clinically, inflammatory myofibroblastic tumor often presents as a firm, mobile, and non-tender mass. Microscopically, inflammatory myofibroblastic nodules are often firm and well circumscribed, often yellow in color, and composed of interlacings of bland ‘spindle‘ cells, mixed with inflammatory elements such as plasma cells, histiocytes, or lymphocytes. Cellular atypia and mitosis are rare. In terms of immunohistochemistry (protein staining), they typically react strongly to smooth muscle actin, and also frequently react to vimentin and cytokeratins.

Treatment and management of inflammatory myofibroblastic tumors of the breast

One of the most important diagnostic aspects of these breast lesions is to differentiate them from malignant spindle cell carcinoma of the breast, and not to over-treat the lesion. Radiological findings for inflammatory myofibroblastic breast tumors also tend to be similar to primary breast cancer tumors, so a biopsy and histological evaluation is always justified. The main concern is to arrive at an accurate diagnosis and not over treat the lesion with grossly unnecessary procedures such as mastectomy, with or without lymph node dissection.

Treatment tends to be conservative

Treatment is usually by surgical excision with conservative margins. Local recurrence is rare but not unheard of, in which case a second excision would be required. Inflammatory myofibroblastic tumors tend to behave in an ‘indolent‘ manner (very slow growing) but have been known to grow aggressively in some cases. As the projected behavior of inflammatory myofibroblastic tumors is largely unknown, a conservative approach of surgical excision with close mammographic follow-up is usually the most appropriate course of action.

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Let’s do a little Q&A quiz…

• What are the inflammatory myofibroblastic tumor pathology outlines? Composed of spindle cells with a variable infiltrate of inflammatory cells and fibrous tissue.
• What is the inflammatory myofibroblastic tumor treatment? Excision. However 25% to 35% recur, but it rarely metastasizes.
• What are the clinical features? 1/3 have associated fever, growth failure, malaise, weight loss, anemia, thrombocytosis, polyclonal hyperglobulinemia, and elevated sedimentation rate. The symptoms disappear after excision of mass. Despite the fact that it all depends on the specific location, which can be anywhere in the body.
• What about the inflammatory myofibroblastic tumor differential diagnosis? These tumors are diagnosed based on their appearance under the microscope by pathologists. Medical image findings are non-specific.

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References

1. Coffin CM, Watterson J, Priest JR, Dehner LP. Extrapulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor). A clinicopathologic and immunohistochemical study of 84 cases. Am J Surg Pathol. 1995;19:859872.
2. Ramachandra S, Hollowood K, Bisceglia M, Fletcher CDM. Inflammatory pseudotumour of soft tissues. A clinicopathological and immunohistochemical analysis of 18 cases. Histopathology. 1995;27:313–323.
3. Rubin BP, Coffin CM, Fanburg-Smith JC. Inflammatory myofibroblastic tumors in adults. Mod Pathol. 2003;16:19
4. Attili, S., Chandra, CR., Heman, DK., Bapsy, PP., Ramarao, C., Anupama, G., Retroperitoneal inflammatory myofibroblastic tumor., World Journal of Surgical Oncology 2005, 3:66.
5. Sastre-Garau X, Couturier J, Derre J, Aurias A, Klijanienko J, Lagace R: Inflammatory myofibroblastic tumour (inflammatory pseudotumour) of the breast. Clinicopathological and genetic analysis of a case with evidence for clonality. J Pathol 2002, 196:97-102.
6. Khanafshar, E., Phillipson, J., Schammel, D., Minobe, L., Cymerman, J., Weidner, N. Inflammatory myofibroblastic tumor of the breast. Annals of Diagnostic Pathology, Volume 9, Issue 3, Pages 123-129 (June 2005).
7. Gobbi, H., Atkinson, JB., Kardos, TF., Simpson, JF., Page, DL., Inflammatory myofibroblastic tumour of the breast: report of a case with giant vacuolated cells. The Breast Volume 8, Issue 3, June 1999, Pages 135-138.
8. Pettinato G,Manivel JC,De Rosa N,Dehner LP. Inflammatory myofibroblastic tumor (plasma cell granuloma). Clinicopathologic study of 20 cases with immunohistochemical and ultrastructural observations. Am J Clin Pathol 1990;94:538–546.
9. Park IK,Yoon DS,Kim YM,Park HD,Min SK. Inflammatory myofibroblastic tumor of the breast. J Breast Cancer 2006;9:258–261.

    

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