CASE 16633 Published on 05.03.2020

Breast implant associated fibromatosis

Section

Breast imaging

Case Type

Clinical Cases

Authors

Dr Naveen Bhatt

Weston Area Healthcare trust

Patient

40 years, female

Categories
Area of Interest Breast ; Imaging Technique Mammography, MR, Ultrasound
Clinical History

A 48-year-old female patient with cosmetic breast implants, over ten years ago, attended A&E with increase in the size of the left breast. There was clinical suspicion of implant rupture due to hard left breast, despite no convincing history of significant trauma. Patient was referred for ultrasound for further assessment.

Imaging Findings

Ultrasound demonstrated 12mm well-circumscribed slightly inhomogenous lesion with posterior acoustic enhancement in the upper-outer quadrant which was classed as BI-RADS 3, (Fig. 1) and no other abnormality in the left breast on targeted scan. The axilla was normal. The hard appearance on clinical examination was not explained by ultrasound. As per our departmental protocol for suspected implant rupture, breast MR with silicone (Figs. 2,3) and STIR sequences sagittal view was performed (Fig. 4), which demonstrate a non-silicone signal in the medial mass with heterogenous signal. Left mammogram demonstrated a subtle lower-half implant indentation in MLO view (Fig. 5), which is better appreciated in the sagittal MR sequence. Mammograms also do not demonstrate any extracapsular implant rupture. MR confirmed no implant rupture and the left-outer half mass. Further, a heterogenous intensity, well-defined mass was displacing implant anteriorly in the lower inner quadrant. This mass was the explanation for the clinically hard appearance of the left breast. This lower inner quadrant mass was suspicious for malignancy. Since non-contrast study was performed due to working diagnosis of implant rupture and a biopsy was the only gold standard to confirm a diagnosis, a repeat MR with contrast study was not warranted.

Post MR, a second look ultrasound was performed and an ultrasound guided biopsy was obtained from upper-outer (Fig. 7) and lower-inner quadrant (Fig. 8) lesions. Histology confirmed the outer half mass to be a lymph node with no suspicious features and the inner half mass as fibromatosis with areas of fat necrosis.

Discussion

Implant associated mass lesion-like fibromatosis is exceedingly rare and a diagnosis of exclusion [1]. There have been very few reported cases and there are no characteristic agreed imaging features which mainly arises from the rarity of such a mass. The usual differential for any breast mass with heterogenous features on imaging is a malignancy. On review of literature, the presentation is variable from a slow growing lesion (as in our case) with benign imaging features to an aggressive lesion with features which resemble a malignant lesion [3]. On mammogram, a large non-calcified mass (Fig. 5 Mammogram LMLO, lower half demonstrates mass between implant and chest wall, Fig. 6 Mammogram LCC, no calcification or implant rupture) often causes indentation but could be spiculated like malignancy, if aggressive. MR is the best modality for assessment of the mass and invasion of surrounding structures like chest wall. It demonstrates variable features but usually heterogenous texture due to mixed stromal nature [2]. Treatment is not well established but variable depending upon regional preferences guided by the multidisciplinary team approach, which in turn is guided by the level of suspicion on histology. Based on this, it varies from wide local excision in general to more aggressive management such as that for a malignant lesion [2]. In our case there were no suspicious features on imaging or histology, and therefore in general management of only surgical excision was recommended. This remains a diagnosis of exclusion with management guided by histology and multidisciplinary approach [4].

Implant associated benign and malignancies [5] are increasingly being recognised and reported in literature. The take home message is that this diagnosis covers a spectrum from benign to malignant features on imaging and working diagnosis for a breast mass is malignancy unless proven otherwise by histology.

Written patient consent for this case was waived by the Editorial Board. Patient data may have been modified to ensure patient anonymity.

Differential Diagnosis List
Implant associated fibromatosis
Breast cancer
Radiation induced fibrosis
Final Diagnosis
Implant associated fibromatosis
Case information
URL: https://www.eurorad.org/case/16633
DOI: 10.35100/eurorad/case.16633
ISSN: 1563-4086
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