The significance of histopathological and immunohistochemical differences of usual ductal hiperplasia, atypical ductal hyperplasia and ductal carcinoma In Situ

Ductal carcinoma in situ (DCIS) and atypical ductal hyperplasia (ADH) can precede invasive breast cancer. Early detection and differential diagnosis of these lesions improves prognosis. Usual ductal hyperplasia (UDH) has low malignant potential. There differential diagnosis is crucial. The aim was to analyze the gender and age of patients, differences in the histopathological and immunohistochemical presentation of UDH, ADH, and DCIS. This retrospective study included archived biopsy samples of 52 patients analyzed at the Institute of Pathology. Data on patient gender and age were obtained from medical records. H/E slides, and immunohistochemical markers (ER, PR, HER2, Ki-67, CK5/6) were used. Data was analyzed using descriptive statistical methods. Average age was 64.1 years. Out of the 52 patients, 49 were female, and 3 were male. The most common finding was DCIS. Isolated DCIS was found in 17% of patients, while 69% had DCIS associated with invasive carcinoma. ADH was isolated in 7% of patients, while 2% had ADH associated with DCIS and invasive carcinoma. UDH was present in 2% of patients. One male patient had UDH, while the other two had DCIS. Among women, the most common finding was DCIS associated with invasive carcinoma. ER was positive in 71.15% of cases and negative in 28.8%. PR was positive in 53.8% and negative in 46.2%. HER2 was positive in 38.4% and negative in 61.6%. Triple-negative status was observed in 5.76% of cases. All patients with UDH were positive for the CK5/6 marker, which was absent in ADH and DCIS. This study highlights the importance of early diagnosis while immunohistochemistry, especially CK5/6 and ER markers, plays a critical role.