Childhood Benign Breast Tumors (Fibroadenoma and Phyllodes)
Incidence and Risk Factors
Benign fibroadenomas are the most common breast tumors seen in children aged 18 years or younger.[1,2] The prevalence of fibroadenoma is 2.2% in females aged 10 to 30 years.[1,2] The incidence increases with age, although girls aged 12 to 16 years tend to have larger lesions than women aged 17 years and older.[3] More than 95% of patients are female. Types of fibroadenoma in children aged 18 years or younger include simple fibroadenoma (70%–90% of cases) and giant juvenile fibroadenoma (0.5%–2% of cases).[2]
Fibroadenomas have been associated with Beckwith-Wiedemann, Maffucci, and Cowden syndromes.[2]
Other benign breast masses include tubular adenomas, benign phyllodes tumors, and benign fibroepithelial neoplasms.[4]
Clinical Presentation
Fibroadenoma usually presents as an asymptomatic mass that can vary in size with a woman's menstrual cycle. They can cause localized pain or breast asymmetry. They can also be associated with skin ulceration and venous engorgement.[2,4]
Giant juvenile fibroadenomas have been variably defined as any rapidly enlarging encapsulated fibroadenoma with a diameter greater than 5 cm, a weight more than 500 g, or displacement of at least four-fifths of the breast.[2,4]
In one retrospective series of 80 girls aged 12 to 18 years with fibroadenomas, 10% of patients had bilateral disease, and 2.5% of patients had unilateral disease but more than one nodule (multicentric fibroadenoma).[3]
Diagnosis
Fibroadenomas are benign biphasic tumors with epithelial and stromal components that have variable mitotic activity.[3] These tumors can be difficult to distinguish from phyllodes tumors when a tumor sample is obtained using fine needle aspiration or core needle biopsy.
Fine needle aspiration is not considered to be adequate for diagnosis. Indications for core needle biopsy or excision of a suspected fibroadenoma in children and adolescents are not based on evidence. The indications include tumor size at presentation of 2 cm to 5 cm (or larger), tumor enlargement during 2 to 12 months of observation, and multiple breast masses or bilateral breast masses.[2,5]
One single-institution retrospective review conducted between 1999 and 2018 aimed to characterize the breast masses of 70 females aged 19 years or younger with fibroadenomas who underwent excision of masses between 2 cm and 16 cm. Histological evaluation found that 87% of the breast masses were benign, 10% of the masses were benign phyllodes tumors that were aggressive in nature (n = 7), one mass was a malignant phyllodes tumor, and one mass was a metastatic sarcoma.[5]
Pathological examination of the core needle biopsy specimen may underestimate or overestimate the aggressiveness of lesions when compared with what is found on excision in about 13% of patients.[5]
Another single-institution retrospective analysis performed genomic profiling on 44 fibroadenomas and 36 giant fibroadenomas.[6] The giant fibroadenomas were biologically distinct from fibroadenomas of the breast, with overexpression of genes involved in the regulation of cell growth and immune response.
Treatment of Fibroadenoma and Phyllodes Tumors
Treatment options for fibroadenoma include the following:
- Observation.
- Surgery.
Observation
Evidence (observation):
- A study of 29 patients with presumed fibroadenomas were diagnosed prospectively over a 13-month period via physical examination.[7]
- Nine presumed fibroadenomas (31%) resolved during the follow-up period of 1 to 12 months, and four presumed fibroadenomas (14%) became smaller.
- Twelve teenagers underwent ultrasonography and had solid masses. None of these masses resolved after a year of observation. In addition, resection determined that all of these masses were fibroadenomas.
There is no evidence that childhood or adolescent fibroadenomas have carcinomatous potential.
Surgery
Indications for resection include tumor size at presentation of 2 cm to 5 cm (or larger); tumor enlargement during 2 to 12 months of observation; multiple breast masses or bilateral breast masses; and patient, parental, or provider anxiety.[1,2]
Evidence (surgery):
- In one series of 39 patients with fibroadenomas who had follow-up after resection, the following was observed:[3]
- Six patients experienced recurrences between 2 years and 7.5 years (median, 4.9 years) later.
- Tumor size, mitotic index, and mesenchymal cellularity did not predict recurrences, and all recurrent tumors were benign.
Surgical complications have included breast hypoplasia, acute pain, and chronic pain.[8]
While recurrence is rare, careful follow-up monitoring is important. Recurrent tumors can be resected successfully using conservative techniques.[8]
Treatment options for phyllodes tumors include the following:
- Surgery.
Surgery (wide local excision without mastectomy)
Phyllodes tumors can be very large and challenging to treat surgically in women with smaller breasts. Complete excision of the phyllodes tumor with grossly negative margins and a small amount of normal tissue circumferentially is necessary. Radical mastectomy or modified radical mastectomy should be avoided. Lymph node evaluation is not necessary.[9]
Phyllodes tumors present a small risk of recurrence, as they fall into the intermediate-grade sarcoma category. These tumors do not metastasize, but they can recur locally.
References:
- Jayasinghe Y, Simmons PS: Fibroadenomas in adolescence. Curr Opin Obstet Gynecol 21 (5): 402-6, 2009.
- Lee M, Soltanian HT: Breast fibroadenomas in adolescents: current perspectives. Adolesc Health Med Ther 6: 159-63, 2015.
- Sun C, Zhang W, Ma H, et al.: Main Traits of Breast Fibroadenoma Among Adolescent Girls. Cancer Biother Radiopharm 35 (4): 271-276, 2020.
- McLaughlin CM, Gonzalez-Hernandez J, Bennett M, et al.: Pediatric breast masses: an argument for observation. J Surg Res 228: 247-252, 2018.
- Zmora O, Klin B, Iacob C, et al.: Characterizing excised breast masses in children and adolescents-Can a more aggressive pathology be predicted? J Pediatr Surg 55 (10): 2197-2200, 2020.
- Yin Lee JP, Thomas AJ, Lum SK, et al.: Gene expression profiling of giant fibroadenomas of the breast. Surg Oncol 37: 101536, 2021.
- Neinstein LS, Atkinson J, Diament M: Prevalence and longitudinal study of breast masses in adolescents. J Adolesc Health 14 (4): 277-81, 1993.
- Javed A, Jenkins SM, Labow B, et al.: Intermediate and long-term outcomes of fibroadenoma excision in adolescent and young adult patients. Breast J 25 (1): 91-95, 2019.
- Valdes EK, Boolbol SK, Cohen JM, et al.: Malignant transformation of a breast fibroadenoma to cystosarcoma phyllodes: case report and review of the literature. Am Surg 71 (4): 348-53, 2005.