Desmoid tumor following abdominally-based free flap breast reconstruction

Desmoid Tumor and Implant-Based Breast Reconstruction

Desmoid tumors are rare locally aggressive myelodysplastic tumors that are usually abdominally based. They account for 0.2% of breast tumors. Certain factors like prior surgery, familial adenomatous polyposis, pregnancy, and high estrogen states are associated with chest wall desmoid tumor occurrence. We present a patient with a history of intraductal carcinoma of the left breast who underwent mastectomy with implant-based reconstruction who had a desmoid tumor of the breast detected during workup for cardiac transplantation for chemotherapy-induced heart failure. The tumor was originally thought to be recurrent breast cancer during workup with imaging obscured by the implant. Excisional biopsy demonstrated a desmoid tumor with a positive deep margin requiring rib resection, synthetic mesh, and pectoralis major flap reconstruction. Breast desmoid tumors are reactive malignancies that have been diagnosed after prior breast implant surgery but without an established risk associated with breast implants. Excision with microscopically negative margins and chest wall reconstruction when indicated is the current established treatment protocol; however, recent paradigm shifts include "watchful waiting" and medical management among treatment strategies.

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

BACKGROUND

Studies suggest that surgical breast augmentation with implants is a risk factor for breast desmoid tumors. The statistical strength of this correlation is unknown, as evidence is limited to anecdotal reports.

METHODS

Patients with breast desmoid tumors and a history of breast implants seen at a single center between 2000 and 2021 were identified via radiology, breast, and sarcoma databases. The standardized incidence ratio (SIR) was calculated to assess the correlation between breast desmoid tumors and breast implants. The cases were pooled with published cases for analyses. Progression-free survival curves and hazard ratios were estimated using the Kaplan-Meier method and Cox proportional-hazards modeling.

RESULTS

Fourteen patients from one institution and 66 cases in the literature were identified. All patients were female, and the mean age was 38 years old (range 20-66). 63 patients (82%) underwent resection, 9 (12%) received chemotherapy, 3 (4%) received sorafenib, 11 (14%) received hormonal therapy, and 3 (4%) underwent active surveillance. After resection, the 2-year recurrence-free survival rate was 77% (95% CI 65%-89%). The recurrence risk was lower for resection with no residual tumor (R0) compared to microscopic (R1) or macroscopic (R2) residual tumor (HR: 0.15; 95% CI 0.02-0.8; p < 0.05). The SIR was 482 (95% CI 259-775) to 823 (95% CI 442-1322), suggesting a 482-823 times higher risk of developing a breast desmoid tumor after breast augmentation than the general population.

CONCLUSION

We present a nonrandom association between breast implants and desmoid tumors. Whether the tumors arise from the surgical trauma or the implant's biomaterial is unknown. When surgery is indicated, negative margins reduce the risk of recurrence.

Fibromatosis of the breast: a 10-year multi-institutional experience and review of the literature

BACKGROUND

Breast fibromatosis is a rare clinical entity, but poses significant diagnostic and therapeutic challenges. In light of recent changes in management practices, the aim was to review our institutional experience of breast fibromatosis and provide a review of current available literature on such management.

METHODS

A search of pathological databases within two tertiary institutions for all patients diagnosed with fibromatosis of the breast over a 10-year period (2007-2016) was performed. Clinicopathological characteristics and modes of treatment were recorded for each patient. Concurrently a comprehensive literature search was performed and studies relating to breast fibromatosis and its management were identified and reviewed.

RESULTS

Sixteen patients were identified. Median age at diagnosis was 42 (range 21-70) and all patients were diagnosed with core biopsy. The most useful imaging modality in diagnosis was ultrasonography and magnetic resonance imaging. 13/16 were treated surgically whilst 3/16 were treated using a watch-and-wait approach. 6/13 (46%) required re-excision of margins and 2/13 (15%) had recurrence after surgery. On review of the literature, there is no dedicated guideline in place for the management of breast fibromatosis. Currently a 'watch and wait' approach is favoured over surgical intervention due to high levels of recurrence and associated surgical morbidity. All cases should be discussed at a sarcoma multidisciplinary team meeting and tyrosine kinase inhibitors should be considered in advanced cases.

CONCLUSIONS

Breast fibromatosis is rare but affects young patients. Active surveillance is now favoured over surgical resection due to high recurrence rates and extensive morbidity. Dedicated guidelines are required to ensure best outcomes.

Screening-detected desmoid tumor of the breast: findings at conventional imaging and digital breast tomosynthesis

Desmoid tumor of the breast is a rare benign entity that usually is mistaken for carcinoma clinically and radiologically. We report two cases of desmoid tumor of the breast detected by mammography screening using digital breast tomosynthesis (DBT). The larger tumor was detected at both full-field digital mammography (FFDM) and DBT. The smaller desmoid tumor, however, was identified only at tomosynthesis. Mammographic and ultrasonographic findings at diagnostic work-up were consistent with carcinoma of the breast. Preoperative needle biopsies could not conclusively diagnose the lesions. Both patients underwent excisional biopsy and histopathology revealed fibromatosis of the desmoid type.