A case report of desmoid type fibromatosis of the breast

Background. Desmoid type fibromatosis of the breast is a rare fibroblastic proliferative disease. It may be sporadic or associated with trauma, Gardner’s syndrome, etc. Desmoid tumour of the breast is a benign, locally aggressive disease. However, it does not metastasize. Case report. We report a case of a 65-year-old woman with right breast desmoid type fibromatosis. Conclusions. Diagnosis of breast desmoid tumour is difficult: clinically and radiologically it may mimic carcinoma. Definitive diagnosis is proved just by histopathological examination results. First choice treatment of breast fibromatosis is a radical surgical excision.


Introduction
Desmoid tumour (syn. aggressive fibromatosis, nonmetastasing fibrosarcoma) is a rare benign fibroblastic proliferative disease. It can occur anywhere in the body: most common places are extremities, abdominal wall and intraabdominal cavity. Desmoid tumour is found in only 0.2% of breast tumours [1]. It may be sporadic, but also it may occur after surgical trauma, implantation of silicone breast implants or may be associated with Gardner's syndrome [2]. Most cases of breast fibromatosis are reported in female, however it may occur in male [2,3].

Case report
A 65-year-old female presented with a palpable lump in her right breast for 5 months. There was no family history of the breast cancer. Her past medical history was significant for total hysterectomy with bilateral salpingo-oophorectomy twenty years ago because of myomatous uterus and benign cysts of ovaries. She reported the onset of menarche at age 14. The patient had two deliveries. During physical examination a 2 cm hard, not tender, with ill-defined margins lump in the upper inner quadrant of the right breast has been found. There was no nipple retraction, discharge or skin change. A breast ultrasound showed a 1.24x0.85 cm suspicious ill-defined hypoechogenic lesion at 1 o'clock position of the right breast ( Figure 1). Mammogram revealed a local hyperdense zone in the right breast ( Figure 2). Histopathological examination of the tumour core biopsy material revealed desmoid type fibromatosis. The patient underwent wide local with clear margins excision of the lesion. Histopathological examination of surgical material confirmed desmoid type fibromatosis ( Figure 3). Tumour was poorly demarcated, composed of spindle-shape myofibroblasts arranged in long sweeping fascicles. There was no mitotic activity. Immuno-histochemical findings of the mass showed a focally positive reaction with beta-catenin, and a negative reaction for CD34, Desmin, CK. The patient did not require any adjuvant treatment. There was no recurrence after two years of follow-up.  Desmoid tumour of the breast is extremely rare: it is found in only 0.2% of breast tumours [1]. Most commonly it is found in one breast; however, both breasts may be affected [1]. Desmoid tumour of the breast may be sporadic, but also it may occur after surgical trauma, implantation of silicone breast implants or may be associated with Gardner's syndrome [2]. Breast fibromatosis may be associated with elevated estrogen levels during pregnancy [2,9]. In our case, desmoids type fibromatosis affected only one breast. Moreover, the patient did not have any history of genetic factors or breast surgery.
Breast desmoid tumour may occur primarily from the breast tissue or secondary from the pectoralis major muscle [1,2]. They are locally aggressive, however, do not metastasize [7].
The treatment of breast desmoid tumour is still controversial because of little data due to low incidence of disease [1]. Surgery, radiotherapy, chemotherapy, hormonal therapy may be used for the treatment [1,4,5]. Radical surgical excision is the treatment of choice [5,9]. However, sometimes the complete excision could be avoided in carefully selected patients because the surgery might have poor functional and cosmetic outcomes (i.e. when superficial and subareolar lesion is present, which may require nipple areolar complex removal) [1]. Desmoid tumours have a tendency to recur [6]. They usually recur within 3 years of excision, and then radical excision is required [2]. Wide local resection prevents or reduces the recurrence of disease [8]. When patients have tumour that is unresectable or require extensive surgical resection (i.e. major chest wall resection) radiotherapy might be performed [4]. Systemic therapy may be used in unresectable, recurrent desmoid tumour [7,9], also for the patients that cannot tolerate surgical treatment and when chest wall is involved [9]. Systemic therapy includes non-cytotoxic (hormonal therapy with Tamoxifen alone or in combination with nonsteroidal anti-inflammatory drugs) and cytotoxic approaches (chemotherapy) [9]. According literature, desmoid tumour may be treated with Tamoxifen due to the fact that fibromatosis may have been related to elevated estrogen levels during pregnancy: treatment with Tamoxifen is associated with reduced size of the tumour [9]. However, postoperative antihormonal therapy does not reduce the local recurrence rate [2]. Methotrexate and/or vinblastine/vinorelbine or an anthracycline-based regimen might be used as "low dose" chemotherapy for desmoids treatment [10]. Targeted therapy (drugs such as imatinib, sorafenib, pazopanib) is a quite new treatment method [10]. Cryoablation also might be used as alternative treatment for local control of small or moderately sized extra-abdominal desmoid tumours [10]. In our case the patient has undergone successful surgery without any adjuvant treatment.
Case report is written according CARE guidelines [11].

Conclusions
Breast desmoid tumour is a rare disease. Clinically and radiologically it may mimic breast carcinoma. Conclusive diagnose of desmoids tumour is made after histopathological examination of the lesion. First treatment of choice is wide surgical resection of the lesion. However, treatment such as radiotherapy, chemotherapy, hormonal therapy may be used. Our case report presents a rare breast desmoid tumour which was successfully treated with local surgical excision without disease recurrence of two years follow up. We believe that small breast desmoid tumours might be treated with wide local excision with clear margins. In such cases aggressive surgical treatment might be avoided considering that breast desmoid tumour is a benign disease. Moreover, each surgeon must consider the cosmetic result of the surgical procedure. We recommend avoid aggressive surgical treatment while treating small breast desmoid tumours. Mastectomy or other extensive surgical procedure might worsen the quality of patient's life. However, when extensive chest wall resection is necessary to achieve a complete resection radiotherapy or systemic therapy should be considered.