The presence of a breast lump is often a reason of great concern. With the recent advances in the technology of ultrasound in the last 20 years, ultrasound could easily differentiate between malignant and benign breast lesions [8].
Radiologists should be aware with different breast benign lesions to be able to distinguish them from the malignant ones. Fibroadenomata are known to be benign tumors composed of stromal as well epithelial components [1].
US is considered to be the best imaging modality in patients younger than 30 years old and pregnant women, as it carried no risk of exposure to radiation, providing imaging-guided biopsy if needed and allowing safe follow up method [4].
Fibroadenomata are known to be the most seen benign tumor in adolescent girls and young-aged patients usually raised from both stroma and epithelium of terminal duct-lobular unit which are of two types both intracanalicular and pericanalicular [7].
The term of complex fibroadenoma referred to the presence of cystic changes with the cysts were more than 3 mm as well as sclerosing adenosis, epithelial apocrine changes, and epithelial calcifications [6].
So the BI-RADS US descriptors of solid breast lesions included margin, shape, lesion boundary, orientation, posterior acoustic features, and internal echo pattern [9].
As the varied management of complex fibroadenomata depended upon differentiation between complex and simple ones, so imaging characteristic of both is worthwhile [9].
In this study, we discussed the accuracy of breast ultrasound in diagnosis of fibroadenoma and differentiate between typical and atypical ones and assess the impact of imaging by ultrasound on patient management (biopsy versus follow up). The diagnoses (whether benign or suspicious criteria) were postulated according to ultrasound. Findings were then correlated with the pathological diagnosis versus follow up.
We had two groups of patients:
Group I is composed of 20 patients with 36 typical fibroadenomas showing typical criteria by ultrasound and by follow up showing stationary course.
Peek et al 2015 (10) stated that up to 59% of FAD showed regression or complete resolution within 5 years. Also, Lee and Soltanian in 2015 stated that 10–40% of fibroadenomas spontaneously regress. But in our study, the 36 typical fibroadenomata showed stationary course throughout their follow up [7].
Ultrasound features of typical fibroadenomas as reported by Kovatcheva et el. 2015 were isoechoic or hypoechoic to fat, oval, or rounded well-defined masses, macrolobulated outline homogenous or heterogeneous internal echotexture, thin echogenic capsule and finely color Doppler showed avascular or low vascular mass [4].
In our study, typical fibroadenomas features were coinciding with the previously forementioned features. Further, 91.6% of the typical FAD were oval in shape, 86.1% showed well-defined borders, 91.6% showed large width than their antero posterior diameter, with homogenous internal echogenicity in about 72.2%, and those with heterogeneous echogenicity were due to either the presence of calcification or cystic degenerations.
Peek et al. 2015 stated that up to 59% of FAD showed complete regression within 5 years [10]. Gordon et al. in 2003 reported that fibroadenomata volume might increase up to 16% in a month in younger women than 50 years, and up to 13% per month in women above 50 years and finally up to 20% in the maximal dimension over 6 months for women of all ages [11]. In our study, the followed up typical fibroadenomas cases show a stationary course throughout the 6-months follow up times.
Group II in our study, 35 fibroadenomata, had atypical criteria by ultrasound; seven were proven to be complex fibroadenomas by pathology. Their ages range from 23 to 41 and mean size (2.3 ± 1.29), while the age of the other patients with typical fibroadenomas (28 typical FAD) ranges from 19 to 39, mean size (1.8 cm).
Lee et al. 2015 reported that the mean age of the 64 patients with complex FA was 40 years (range, 22–66 years) and mean size 1.44 cm, range (0.5–7 cm) were larger than the simple FAs (mean, 1.21 cm; range, 0.6–8 cm), but the difference was not statistically significant [12].
According to Pinto et al. 2014, the mean age of complex fibroadenoma group was 42 years (range, 22–70 years) and mean size 1.9 cm, which were larger than simple fibroadenomas mean size (1.9 versus 1.3 cm) coinciding with our study [9].
Gogoi and Borgohain in 2015 stated that complex fibroadenoma occurred in older patients (median age 47 years) compared to simple fibroadenoma (median age 28.5 years) and often it was smaller in size (1.3 cm average diameter) [6].
Also, Kuijper A et al. in 2001 reported that CF were smaller than simple fibroadenomas and measures on average 1.3 cm as compared to simple fibroadenoma, the average size of which 2.5 cm [13].
Ultrasound features of complex fibroadenomata as reported in Selvi 2015 were heterogeneous echotexture, internal cysts, and sclerosing adenosis particularly in the periphery can cause angular margins [5].
Some ultrasound features might place the lesion in the BIRADS category 4a or higher and that might require a biopsy to rule out malignancy like angular margin, more than three lobulations or microlobulations and also calcification casting acoustic shadowing.
Dupont et al. [14] found out that 22% of the reported fibroadenomata were pathologically proven complex as well as Sklair–levy et al. 2008 also declared that 15.7% of biopsy-roven fibroadenoma were complex [15].
In addition, Pinto et al. 2014 also detected that 16% of biopsy-proven adenomas were complex ones. All of them were nearly matching our study which stated that 20% of pathologically proven were complex [9].
Dupont et al. in 1994 noted that the cumulative risk of invasive breast carcinomas in women with complex FAs was 3.1 times greater than the risk in the normal population and 1.89 times greater than that in women with simple FAs. They recommended that patients with complex FAs should undergo screening mammographic surveillance, beginning at age 35 or 40 years. In contrast, other investigators in a multicenter study have suggested that complex FA without atypia on histology confers no significant increase in risk of subsequent breast cancer [12].
Sklair–Levy et al. 2008 reported a low incidence of malignancy (1.6%) in complex FA during a mean follow-up period of 2 years; as a result, they suggested conservative management for women with complex FA [16]. Peek et al. 2015 reported that malignant transformation within FAD is considered exceptionally rare (0.002–0.0125%) and there is a 1.3–2.1 increased risk of breast cancer in women with FAD compared to the general population [10]. Gogoi and Borgohain in 2015 stated that the incidence of carcinoma developing in a fibroadenoma is only 0.1 to 0.3%. Sanders et al. in 2015 A retrospective analysis of the pathologic findings of core biopsy of 2062 fibroadenomas (FA) and their long-term outcome revealed malignancy or atypia in 12 (0.58%) [17]. In our study, one out of the seven pathologically proven complex fibroadenoma changed to carcinoma in follow up after 6 months.
Regarding value of color Doppler, Lee et al. in 2015 concluded that the degree of vascular flow in complex FAs was significantly higher than it was in simple FAs and that complex fibroadenomata tended to have more aggressive features and high BIRADS category on gray scale ultrasound [12] According to Hooley in 2013, the irregular branching central or penetrating vascularity within a solid mass raised suspicion of malignant neovascularity [15].
In our study, complex FAD demonstrated more frequent central arrangement of mild vascular flow than simple fibroadenoma (85.7% versus 0 %, p < 0.01) and that 71.4% of complex fibroadenomata showed high BIRADS (4a or 4b) than simple ones (2 or 3).
Pinto et al. in 2014 reported that complex fibroadenomas presented more frequently with an oval shape, circumscribed contours, a parallel orientation to the skin surface, no posterior acoustic features, and no calcifications [9].
While Lee et al. in 2015 stated that complex fibroadenomata represented more with round to irregular shape and uncircumscribed margin and the other features like echogenicity, posterior acoustic pattern, boundary, and orientation of masses did not differ significantly between the two groups (p > 0.05) [12].
In our study, complex FAD showed more frequently oval shape in about 71.4%, isoechoic texture in 57.2%, uncircumscribed contour in 57.2% lesions, parallel orientation to the skin surface in 71.4% lesions, and finely posterior enhancement 100% in all lesions.
As a result, the ultrasound features including vessel arrangement and posterior features show significant difference between typical and complex FAD with p value of < 0.01.
Small descriptive study done by You et al. in 2010 demonstrated that complex fibroadenomas frequently presented with cystic changes and a complex echo texture [18]. In our study, 57.2% of complex fibroadenomas presented with isoechoic texture. Further, 28.5% present with calcification and cystic degeneration, 42.8% present with cystic degeneration only with no significant difference. Also complex fibroadenomas showed associated findings as fibrocystic changes more than simple ones (57.1% versus 7.1% with no significant p values).
Substantial physiological changes during pregnancy and lactation made it challenging to evaluate patients presenting with a breast problem. Most findings in pregnant and lactating patients were benign. Ultrasound was the first-line recommended imaging modality for all pregnant women and for lactating patients less than 30 years of age [3].
Joshi et al. in 2013 stated that during pregnancy, fibroadenomata sometimes showed atypical features like cystic changes, increased vascularity, and/or prominent ducts. The presence of atypical features such as microlobulations, irregular outline, heterogeneous echogenicity, posterior acoustic shadowing, and extensive hypoechogenicity should lead to percutaneous core biopsy to confirm the diagnosis [3].
In our study, six pregnant cases with FAD showed atypical criteria, one of them showed microlobulated outline, one showed increase vascularity, while the remaining five showed vascular arrangement of central and peripheral position.
Two out of six were proven to be typical FAD by biopsy, and the other four showed stationary course during their follow up after delivery.
So in our study, ultrasound showed high sensitivity (100%), specificity was 74%, PPV was 46%, while NPV was 100% in the initial diagnosis and characterization of fibroadenomata.
In our study, we verified the role of ultrasound and color Doppler in the diagnosis of fibroadenomata as well as the differentiation between simple and complex fibroadenomas for optimal management (biopsy versus follow up).
