Breast fibromatosis: Making the case for primary vs secondary subtypes

Abstract

Fibromatosis of the breast is a rare condition that can be locally aggressive. The mainstay of treatment remains wide local excision, with varied adjuvant therapy as needed. The authors describe their experience in the treatment of a series of patients and propose the classification of primary and secondary breast fibromatosis. A single‐institution retrospective analysis of patients treated for breast fibromatosis from 2003 to 2017 was completed. Demographic data, pertinent past medical history, and treatment modalities were reviewed. Primary breast fibromatosis was defined as arising in the absence of previous surgery or radiation therapy to the ipsilateral breast. Secondary breast fibromatosis was defined as arising in the setting of previous surgery or radiation therapy to the ipsilateral breast. A total of 16 patients were included with the median age 40 (28‐64) years. The average size of the lesion was 6.37 cm (range of 1.5‐15 cm). Mean follow‐up time was 65 months. Surgical excision was completed in 14 patients, with two recurrences. There were no recurrences in patients with surgical margins >1 cm. Two patients were treated nonsurgically. There were seven patients with primary fibromatosis of the breast and nine patients with secondary fibromatosis of the breast. Fibromatosis of the breast is difficult to diagnose prior to surgical excision. We advocate for the multi‐disciplinary treatment of this disease process with an aggressive surgical approach to achieve margins >1 cm.

When to Cut: A Case of Breast Fibromatosis

“…3 In a retrospective analysis, ultrasound identified an abnormality (textural change with shadowing) in all 15 included cases of breast fibromatosis, but only 40% identified a mass. 4 In the same study, MRI detected a mass in 62.5% of cases, with identifying features of an isointense lesion on T1-weighted imaging. Core needle biopsy is essential in the diagnostic workup, with histology showing proliferation of spindle cells.…”

“…On average, primary breast fibromatoses are smaller, with an average size of 3.84 cm compared to secondary cases which average 7.12 cm in the greatest dimension. 4 It is likely that our patient's left breast fibromatosis was a case secondary to her lumpectomy, as her lesion was large and has not recurred in the 8 years since resection. However, her history of an additional desmoid type tumor in her leg points towards a genetic predisposition, indicating her status as a potential "mixed" etiology.…”

“…A case can either be classified as primary or secondary fibromatosis. 4 Cases of primary breast fibromatosis are linked to genetic predisposition (ie, familial adenomatous polyposis). Cases of secondary breast fibromatosis are linked to prior trauma such as surgery or radiation.…”

“…On average, primary breast fibromatoses are smaller, with an average size of 3.84 cm compared to secondary cases which average 7.12 cm in the greatest dimension. 4…”

A nonrandom association of breast implants and the formation of desmoid tumors

“…3 Also, cases 1, 9, 10, 11, and 12 are included in a breast desmoid case series performed at the same institution. 8 The patients were all female and the mean age at diagnosis was 38 years old (range 20-66 years). 54 (74%) patients had silicone implants, 12 (16%) had saline implants, 2 (3%) had a saline implant that was subsequently exchanged with silicone, 2 (3%) had silicone exchanged with saline, and 3 (4%) had silicone exchanged with different silicone implants.…”