Juvenile Fibroadenoma Detected at 2 Years and Rapid Growth at Thelarche: Case Report and Literature Review

Abstract

Juvenile fibroadenoma typically is seen in the adolescent patient and has distinctive clinical and histopathological features that are related to the early onset of the benign tumor. Only rarely can juvenile fibroadenoma occur as a prepubertal lesion or may be detected earlier in childhood, raising questions about differential diagnosis and management of the lesion. We present a case of very early first manifestation of juvenile fibroadenoma in a 2-year-old patient. Under clinical observation and conservative management over a 7-year period, there was no progression. At the age of 9 years, rapid growth of the lesion occurred causing clinical symptoms. Complete surgical excision resulted in a good clinical outcome. Histologically, the diagnosis of juvenile fibroadenoma was made. In summary, juvenile fibroadenoma is the most common breast neoplasia in adolescents and may cause excessive unilateral growth resulting in gross asymmetry and pain. However, it can be detectable in early childhood and after a dormant period of several years, as in this case, lead to sudden massive growth at the onset of puberty. The clinical management should include an interdisciplinary treatment approach with gynecology, pediatrics, and pediatric surgery to balance the risks and benefits of conservative management. Surgical removal can be safely postponed until it becomes necessary due to clinical symptoms.

Keywords: Benign breast lesions; breast developement; juvenile fibroadenoma; mammary gland biology; multidisciplinary treatment of breast lesions in childhood.

Figure 1.

(A) Clinical presentation of the then 2-year-old girl in 2015: The left breast was swollen, but did not cause any complaints. (B) Clinical presentation of the 9-year-old patient in 2023: In addition to the massive swelling, there is a marked redness of the left breast. (C) Clinical presentation 2 weeks after surgery.

Figure 2.

(A) Sonographic image of the first diagnosis of the mass in 2015. The fibroadenoma in the retromamillary area of the left breast presents as an encapsulated, oval, homogeneous, isodense subcoutaneous tumor measuring 27 mm. (B) Follow-up after 2 years shows a slight regression of the mass. (C) On presentation for treatment in 2022, the tumor has grown to the size of 55 mm with irregular shape.

Figure 3.

Intraoperative situs: The lobulated fibroadenoma is bluntly extirpated with intact capsule.

Figure 4.

Macroscopic aspect of the surgical specimen: The capsule and the binodular structure are clearly visible.

Figure 5.

HE-stained slide: Cell-rich, mitotically active stroma without atypia. The proliferative epithelial changes show the picture of gynecomastoid epithelial hyperplasia.

Figure 6.

Clinical presentation of the 9-year-old patient 6 weeks after surgical removal of the juvenile fibroadenoma from the left breast: The scar is unremarkable without any signs of inflammation. The slight residual swelling of the left breast decreased further in the following weeks.