According to Stanford School of Medicine, juvenile fibroadenoma of the breast is defined as circumscribed, often large, breast mass usually occurring in adolescent females with stromal and epithelial hypercellularity but lacking the leaf-like growth pattern of phyllodes tumors [
8]. Diagnostic criteria for juvenile fibroadenoma are (1) circumscribed and rarely multiple; (2) biphasic stromal and epithelial process in which pericanalicular pattern is most common and lacks leaf-like growth pattern in uniformly hypercellular stroma. Fibrotic areas may be present; (3) lack of atypical features in stroma-like periductal increase in cellularity, stromal overgrowth, cytologic atypia, and mitotic rate >3/hpf; (4) frequent epithelial and myoepithelial hyperplasia; (5) most patients' age is 10–20 years with a mean age of 15 years. Juvenile fibroadenomas may be multiple [
8].
Giant fibroadenoma is defined as a tumor >500
gms or disproportionally large compared to the rest of the breast. It is more frequently seen in young and black patients. Giant fibroadenoma may be either adult type or juvenile fibroadenoma [
8,
9].
Giant juvenile fibroadenoma simultaneously occurring in both the breasts is very rare. Four case reports are available in the English literature [
3,
5–
7]. Giant juvenile fibroadenoma is an uncommon tumor presenting in adolescent females and the exact etiology is not known. Hormonal influences are thought to be contributing factors [
9]. Excessive estrogen stimulation and/or receptor sensitivity or reducedlevels of estrogen antagonist during puberty have been implicated in pathogenesis [
9,
10].
It is necessary to exclude the close differentials of juvenile fibroadenoma which are benign low-grade phyllodes tumor, virginal hypertrophy, and other rare differentials such as lipoma, hamartoma, breast abscess, macrocyst, adenocarcinoma, and pseudoangiomatous stomal hyperplasia, as the treatment modalities and the prognosis differ quite significantly in these various conditions. Some of the lesions were treated by mastectomy, but some lesions may require only local excision, aspiration, or conservative management [
10–
12].
Giant juvenile fibroadenoma is a benign tumor, and total excision of the lump with conservation of nipple and areola is the optimal treatment [
10–
12].
Benign low-grade phyllodes tumor occurs in the older (>40 years) age group and has no racial predisposition. Generally, they present as a solitary mass confined to unilateral breast, and bilateral involvement is rarely seen [
10]. In low-grade phyllodes tumor, prominent leaf-like architecture is seen due to stromal cellularity and, there is a characteristic stromal condensation around the ducts, and it infiltrates the surrounding breast tissue with mitotic figures <4/hpf. In high-grade phyllodes tumor, stromal overgrowth with atypia and atypical mitotic figures (<10/hpf) are seen. It is treated by wide excision with a margin of normal tissue or mastectomy [
10,
11,
13,
14].
In juvenile breast hypertrophy, rapid and distressing enlargement of one or both breasts occurs, which is often asymmetrical and occasionally in an adolescent female. Histological examination shows abundant connective tissue and duct proliferation, frequently with epithelial hyperplasia but little or no lobule formation. It is treated by reduction mammoplasty [
10,
12,
14].
Giant lipoma can cause unilateral breast hypertrophy. Soft, mobile mass can be felt on palpation. Lipoma consists of encapsulated nodules of mature adipose tissue on histology [
10,
12,
14].
Breast abscesses developing during puberty cause sudden and rapid growth in the breast. Pain, fluctuation, and erythema are present. Histological examination reveals focal collection of polymorphs with necrotic material in the lobules. Hamartomas can be easily suspected on imaging with their multilobular structures. Microscopically, these lesions are composed of an admixture of ducts, lobules, fibrous stroma, and adipose tissue in varying proportions [
13,
14]. Pseudoangiomatous stromal hyperplasia reveals complex interanastomosing spaces, some of which have spindle-shaped stromal cells at their margins simulating endothelial cells [
10,
12,
14]. FNAC and biopsy easily rule out these conditions.
It is essential to know that giant juvenile fibroadenoma may recur after complete excision, and the chance of recurrence becomes less after the third decade [
13]. In view of bilateral giant juvenile fibroadenomas, possibility of Carneys complex should be considered, which constitutes multiple myxoid fibroadenomas, endocrine hyperactivity, cardiac myxoma, cutaneous hyperpigmentation, and other abnormalities [
14].
In our case, other components of Carneys complex were absent with the lack of family history except for multiple fibroadenomas.
Isolated case reports ofunilateral juvenile fibroadenoma and multiple giant fibroadenoma in single breast were available [
9,
12,
15,
16]. In the literature, only four case reports of bilateral giant juvenile fibroadenomas were reported [
3,
5–
7]. The last case was reported in 2009 [
7]. To conclude, we present an extremely rare case of bilateral giant juvenile fibroadenomas of breasts. The case was diagnosed on FNAC and subsequently confirmed on histopathology. The patient is treated by the removal of both the fibroadenomas conserving the breast tissue. The patient is doing well with regular followup.
