Microinvasive lobular carcinoma arising in a fibroadenoma

Breast carcinoma arising in a fibroadenoma: A case series of 16 patients and review of the literature

Breast carcinoma arising from a fibroadenoma is an uncommon entity and is frequently detected incidentally during pathological examination or excisional biopsy of a benign breast tumor. Due to only sporadic cases being reported, evidence-based guidelines are not well-established to date. The present report describes 16 patients diagnosed with breast carcinoma arising within a fibroadenoma in the Third Hospital of Nanchang (Nanchang, China) between January 2019 and December 2021 and discusses the clinicopathological characteristics, imaging findings and treatment. The age of patients at diagnosis ranged between 19 and 58 years and a well-defined asymptomatic mass was the most common clinical presentation. Carcinoma occurring in fibroadenoma generally mimics a benign tumor and potential carcinomatous changes may not be detected. Pathologically, carcinoma in situ was the predominant subtype in the present study. Additionally, ductal carcinoma in situ was more common compared with lobular carcinoma in situ in the present case series. Regarding the molecular phenotypes, the majority of cases were categorized as luminal subtype, although other subtypes such as triple-negative and HER2 positive breast cancer were also identified. In the present study, seven patients were treated with breast-conserving surgery and nine patients were treated with mastectomy. Sentinel lymph node biopsy was performed in all patients and none exhibited axillary node metastasis. Additionally, six patients underwent radiotherapy and two received chemotherapy. During the follow-up, all patients were alive and no evidence of disease relapse was observed. In summary, clinicians should be aware of the possibility of carcinoma within a fibroadenoma, which could alter the therapeutical course. Adequate biopsy or excision should be performed in patients with indicators of malignant transformation in a presumed benign breast tumor.

A case of fibroadenoma with lobular carcinoma in situ and microinvasion in a young woman

Fibroadenomas are benign breast tumors with a rare incidence of malignant transformation. Carcinoma arising within fibroadenomas typically occurs in women above the age of 40. We present a case of a young patient with microinvasive carcinoma arising within a biopsy-proven fibroadenoma, highlighting the possibility of carcinoma arising within fibroadenomas in young patients and the importance of vigilant surveillance even after a benign biopsy. In younger patients, new suspicious changes in benign lesions should be investigated. If prior core needle biopsy was performed, excision biopsy should be considered as the malignancy may be small and may be missed on needle biopsy.

Bilateral breast cancer with a unilateral carcinoma within a fibroadenoma: A case report

Fibroadenomas are a type of benign tumor that occur in young women below the age of 35 years old. The tumors are the second most common type of tumor after fibrocystic disease. The chance of carcinoma arising in a fibroadenoma is extremely low. To date, <130 such cases have been reported. Previous studies have reported that fibroadenomas can evolve into a number of different types of malignancy. The present study is the first to describe a case of bilateral primary breast cancer with a unilateral invasive ductal carcinoma within a fibroadenoma. The current study presents a case of a 48-year-old female who presented with 2 stiff lumps on bilateral breasts, diagnosed as bilateral breast carcinoma, with a unilateral invasive ductal carcinoma within a fibroadenoma in the right breast. The patient underwent a bilateral mastectomy and subsequently received 4 cycles of chemotherapy (epirubicin, 60 mg/m² and cyclophosphamide, 600 mg/m²) every 21 days, followed by 4 cycles of docetaxel chemotherapy (100 mg/m²) every 21 days. The patient then received maintenance endocrine therapy (tamoxifen, 20 mg, twice daily) for 19 months. The patient was followed up every 3 months, and at the last follow-up examination in May 2015, the patient exhibited no signs of recurrence.