An update on the use of immunohistochemistry and molecular pathology in the diagnosis of pre-invasive and malignant lesions in gynecological oncology.

Objective: One of the most common challenges in everyday clinical practice of gynecological oncology is to identify the type and the primary origin of a tumor. This is a crucial step in the management, treatment, prognosis, and survival of patients suffering from a gynecological malignancy. Immunohistochemistry has been widely adopted over the last three decades in pathology laboratories all over the world. Recent advances in our understanding of the differentiation of gynecological tumors based on immunohistochemical expression have resulted in use of immunohistochemistry as a major diagnostic tool in gynecology, for precise tumor classification. More recently, advances in molecular pathology, have taken this disease sub-classification further resulting in more effective personalised treatment regimens. The aim of this review is to provide clinicians with up to date information on the various immunohistochemical and molecular tests used in the diagnosis of gynecological malignancies of the female genital tract and an understanding of how to interpret them.

Methods: We performed a review of the current literature including review articles, original research articles, and guidelines on various immunohistochemical markers and molecular techniques which are used for the differential diagnosis of gynecologic malignancies.

Conclusions: Immunohistochemistry is useful as an objective means for improved diagnostic reproducibility, accuracy, and precise classification in cases where the diagnosis with histochemical stains is inconclusive, providing a more reliable estimate of clinical outcomes. The diagnosis, in some cases, can be further refined by the use of molecular techniques leading to personalised medical treatments.