28581 – PSEUDOLACTATIONAL SECRETORY HYPERPLASIA (PREGNANCY-LIKE HYPERPLASIA) WITH ATYPIA: A CASE SERIES AND LITERATURE REVIEW

Abstract

Introduction: Pseudolactational secretory hyperplasia (PLH) or pregnancy-like (pseudolactational) hyperplasia is a rare
condition associated with an incidental finding in biopsies investigating benign and malignant breast lesions. These lesions
affect non-pregnant women, typically between the 4th and 6th decades of life, with no described relationship to prior
oncological diagnosis or previous pregnancy and lactation. Its frequency is approximately 3%, considering findings from
surgical and autopsy reports. Histologically, they are lobulocentric epithelial lesions with characteristic intra- and extracellular secretions, similar to lactational changes. Additionally, they often present cytological alterations with nuclear
atypia, which may exhibit atypical ductal hyperplasia, ductal carcinoma in situ, and, more rarely, associated intraluminal
calcifications, which may be the mammographic sign indicating the need for biopsy. Hypersecretory cystic hyperplasia
(HCH) is a histological condition that may be associated with PLH in 33% of cases. The relationship between PLH with
atypia and HCH and the development of breast carcinoma is not well defined, and surgical excision of the biopsied lesion
is indicated for diagnostic confirmation. Methodology: Case series report with a review of medical records and literature
on the topic. Conclusion: Pseudolactational hyperplasia is a rare breast alteration that presents as microcalcifications
or a mass lesion on imaging exams, diagnosed through histopathological and immunohistochemical studies by biopsy.
Surgical treatment is indicated in the presence of morphological criteria for precursor lesions of neoplasia, as demonstrated in one of the cases. This highlights the importance of resecting the area of PLH with atypia to rule out the association with breast carcinoma in situ.