Fibromatosis of the Breast: Diagnostic Accuracy of Core Needle Biopsy

Fibromatosis of the breast is an uncommon neoplasm with potential for local recurrence. Given the option of observation after diagnosis by core needle biopsy (CNB), we sought to evaluate the accuracy of CNB for diagnosing fibromatosis. We identified a total of 31 cases in which fibromatosis had been diagnosed or included in the differential diagnosis on a CNB, an excision, or both. Morphology and immunohistochemical results were reviewed. Of 26 cases confirmed as fibromatosis on excision, 22 (85%) were diagnosed as fibromatosis or fibromatosis was favored in the differential diagnosis on CNB. More frequent use of immunohistochemistry would likely have resulted in a greater number of definitive diagnoses. Fibromatosis was rarely mistaken for other nonmalignant stromal lesions, with no cases misdiagnosed as carcinoma. CNB can be an accurate method of diagnosing fibromatosis, allowing observation for a select group of patients.

Fibromatosis of the breast is a rare benign disease compromising <0.2% of all primary breast tumors. Although the chest wall is a common location, occurrences of implant-associated fibromatosis of the breast are extremely rare; only 33 cases have been reported. We present a case of a 42-year-old female who underwent breast augmentation with silicone breast implants, and 2 years later developed an aggressive implant-associated fibromatosis of the breast and chest wall. On imaging studies, the tumor mimicked breast carcinoma, and despite chemotherapy, the fibromatosis rapidly enlarged and was locally invasive requiring wide surgical excision. Unlike previously reported imaging findings, magnetic resonance imaging revealed an oval circumscribed mass with fringe-like internal architecture. We provide a review of the literature and discuss the imaging features of implant-associated fibromatosis of the breast.

Desmoid – type fibromatosis(DF) is a rare mesenchymal lesion with high risk of local recurrence. Specific beta-catenin mutations (S45F) appeared to be related to this higher risk compared to T41A mutated or wild type (WT). We explored the influence of both mutations and WT on structure stability and affinity of beta-catenin for alpha-catenin and the pattern of gene expression that may influence DF behavior. Using 33 surgically resected primary DFs harboring T41A (n=14), S45F (n=10) or WT (n=9), we performed a comparative molecular analysis by protein/protein interaction modeling, gene expression by DASL microarrays, human inflammation gene panel and assessment of immune system-based biomarkers by immunohistochemistry. Mutated proteins were more stable than WT and formed a weaker complex with alpha-catenin. Consensus unsupervised gene clustering revealed the presence of two DF group- mutated (T41A+S45F) and WT (p= 0.0047). The gene sets “Inflammatory- Defense- Humoral-Immune Response” and “Antigen Binding” were significantly enriched in T41A. The deregulation of 16 inflammation-related genes was confirmed. Low numbers of T- cells and TAM infiltrating the tumors and low/absent PD-1/PD-L1 expression were also identified. We demonstrated that mutated DFs (T41A or S45F) and WT are two distinct molecular subgroups with regard to beta-catenin stability, alpha-catenin affinity and gene expression profiling. A different inflammation signature characterized the two mutated groups, suggesting a mediation either by T41A or S45F. Finally, all mutated cases showed a low number of TIL and TAM cells and a low or absent expression of PD-1 and PD-L1 consistent with beta-catenin activation insensitive to check-point blockade.

This study aimed to evaluate the diagnostic and prognostic value of immunohistochemical staining with anti-non-phospho beta- catenin antibody, which might more accurately reflect the aggressiveness of desmoid-type fibromatosis, in comparison to the conventional anti-beta-catenin antibody. Between 2003 and 2015, 40 patients with extra-peritoneal sporadic DF were prospectively treated with meloxicam or celecoxib, a COX-2 inhibitor, therapy. The positive nuclear expression of non-phospho beta-catenin showed a significant correlation with positive CTNNB1 mutation status detected by Sanger method (p = 0.025), and poor outcome in COX-2 inhibitor therapy (p = 0.022). In contrast, nuclear expression of beta-catenin did not show a significant correlation with either CTNNB1 mutation status (p = 0.43) or outcome of COX-2 inhibitor therapy (p = 0.38). Nuclear expression of non-phospho beta-catenin might more appropriately reflect the biological behavior of DF, and immunohistochemical staining with non-phospho beta-catenin could serve as a more useful diagnostic and prognostic tool of COX-2 inhibitor therapy for patients with DF.

Interventional radiology has revolutionized the local management of bone tumours, offering new minimal invasive alternatives to surgery and radiotherapy. Its role has continuously increased over the past years for the treatment of benign tumors and also of some malignant ones, especially in palliative situations. The development of protective techniques and new ablative technologies, such as cryoablation, contributes to expand the role of the interventional radiologist to new fields of applications in musculoskeletal oncology.

The goal of this review is to investigate the possible correlation between BDT and breast implant surgery. The search revealed 36 cases of BDT associated with silicone breast implants. Based on the reviewed data, the incidence of BDT following breast implant surgery is lower than BDT in the general population. At the moment, a possible association between breast implants and the development of breast desmoid tumors cannot be unequivocally confirmed.