Thyroid transcription factor 1 immunohistochemistry as an intraoperative diagnostic tool at frozen section for distinction between primary and secondary lung tumors.

Context: Intraoperative distinction between primary and metastatic carcinomas in the lung at frozen section remains problematic.

Objective: To assess the value and practicality of immunohistochemistry for thyroid transcription factor 1 at the time of intraoperative frozen section.

Design: Thirty-three patients presented with either a solitary pulmonary mass or 2 pulmonary masses and a history of carcinoma in a different organ.

LIM domains-containing protein 1 (LIMD1), a tumor suppressor encoded at chromosome 3p21.3, binds pRB and represses E2F-driven transcription.

LIM domains-containing protein 1 (LIMD1) is encoded at chromosome 3p21.3, a region commonly deleted in many solid malignancies. However, the function of LIMD1 is unknown.