Background:

To evaluate the imaging findings in patients with breast cancer diagnosed before age 40 and their correlation with histological type and molecular subtype.

Methods:

A descriptive, retrospective, single-center study was conducted by reviewing imaging exams and medical records, after approval of the institution’s Ethics Review Board. Among the 120 patients studied, 112 (93.3%) had mammography, 113 (94.2%) underwent ultrasonography and 105 (87.5%) underwent breast magnetic resonance imaging (MRI). Histopathology data was performed in most cases after surgical resection, which was available for 113 patients (94.2%).

Results:

The mean age at diagnosis of primary breast cancer was 34 years. Most patients had no family history of breast cancer or ovarian cancer (60.7%), and were symptomatic at diagnosis (75.6%). The most common histological type was no-special type (NST) invasive carcinoma (73.8%). Regarding the molecular subtype, luminal B was the most common (42.6%), followed by triple negative (20.2%). The malignant tumor was identified in 92.9% of patients who underwent mammography, 96.5% of patients submitted to ultrasound and 98% of those who performed MRI. MRI was superior to other methods in the evaluation of multifocal and multicentric lesions. There was no statistically significant association between imaging findings and molecular subtypes in the present study.

Conclusions:

This study demonstrated that imaging methods play a fundamental role in the characterization of cases of breast cancer diagnosed in patients younger than 40 years. Despite the ultrasound has been the most widely used method, we found improved characterization of breast lesions when also used mammography and MRI (AU)