A 44 yearold woman underwent a core needle biopsy of a small cluster of microcalcifications in her left breast, that proved benign, specifically a B2 class.
On July, 2016 she turned to Brotzu Breast Department to undergo a mammogram, that showed a small area of distortion with a few punctate calcifications in the same location where the biopsy was obtained.
The patient had no records, therefore the mammogram findings, although very likely related to the scar tissue resulting from the biopsy, had to be considered a potentially suspicious lesion (BIRADS 4).
To thoroughly investigate the case, an ultrasound exam was chosen:it confirmed a large irregular hypoechoic area of parenchymal distortion in the middle of the outer quadrants of the left breast. The lesion, 15 mm diameter, had small and long hypoechoic spicules , a few central microcysts and absence of posterior acoustic signs. Doppler ultrasound showed peripheral and central vascularization. Ultrasound assessment of the left axilla revealed the presence of small nodes with no evidence of a hyperechoic central hilum.
Ultrasound exam assigned the lesion to BIRADS4 class.
The controlateral breast ultrasound exam did not show any evidence of pathology.
An MRM and ultrasound guided biopsy were carried out because the ultrasound findings could not confirm the surgical scar hypothesis.
MRI showed a non-mass lesion with high and early enhancement, 18 mm diameter, leaning to a proliferative lesion, classified as BIRADS 4c class.
The hystological exam revealed a complex sclerosing lesion with proliferative aspects.
Pathological examination of the mass showed scleroialinosic units with entrapped dysmorphic ductal structures and normal mioepithelium(p63+)surrounded by florid sclerosing adenosis, by florid ductal hyperplasia and papillomatosis with a few microcysts that vanish periferically.
Complex sclerosing lesions are benign breast lesions, characterized by a central fibroelastotic core with ducts and lobules radiating outward, giving the lesion its characteristic stellate appearance;the term radial scar is used when lesion is smaller than 15 mm.
Its incidence is 0.3-0.7%.
It is considered a B3 lesion, which is a lesion of uncertain malignant potential, just like atypical ductal hyperplasia, flat epithelial atypia, classical lobular neoplasia, papillary lesions, benign phyllodes tumor and radial scar. The incidence of post bioptical B3 hystological diagnosis is 4-9%.
Underdiagnosis and its uncertain malignant potential make management difficult.
Patients used to be definite candidates of surgical excision, nowadays it’s preferred to find diagnostic approaches that confine surgical procedures, more invasive both to the patients and the sanitary costs.
The prognosis of RS/CSL depends on the presence of associated atypia: when RS/CSL shows atypia surgical excision is mandatory.
According to recent literature data, RS diagnosed on core needle biopsy or vacuum assisted biopsy is to therapeutically excise the lesion seen on imaging by vacuum assisted biopsy and no longer by open surgery with follow up surveillance imaging for 5 years.
In several studies focused on the MRI role in the diagnostic process of B3 lesions, it appears that the enhancement or the absence of it, could discern the therapeutic choice.
Radial scar or complex sclerosing lesion on mammography appears as a stellate lesion with a radiolucent core and long, thin radiating spicules; less frequently it appears as a distortion area, focal asymmetric density, microcalcifications, or nodular opacities.
Ultrasound does not always allow differentiation of radial scar or complex sclerosing lesion from a malignant lesion, because it might appear similar to a parenchymal distortion with irregular echo patterns or a spiculated lesion with or without ultrasound shadowing.
MRI findings are various: foci(small enhancement areas smaller than 5 mm); masses(space occupying lesion larger than 5mm); non mass-lesions (non occupying space lesion, whose enhancement appears scattered in the fatty and gland healthy tissue); distortions.
In only a small percentage of cases, MRI cannot show complex sclerosing lesion.
In our specific case, a surgical approach was chosen considering the latest scientific studies, the size of the lesion, and the MR enhancement of the lesion.
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