Imaging and histopathological features of Jacob's disease: a case study.

A pathologically elongated coronoid process forming a joint with the zygomatic arch and bone is termed as "Jacob's disease." Herein, we present a case of Jacob's disease, which has rarely been reported in the literature. Moreover, very few cases have been reported from the Indian subcontinent. A 28 years-old male reported to us with progressive restriction of mouth opening. After detailed imaging, coronoidectomy was performed through an intraoral approach. A mushroom-shaped gross specimen was obtained. Osteochondroma of the coronoid process was diagnosed based on the histopathologic examination of the excised tissue. Although Jacob's disease is seldom considered in the list of differential diagnoses for restricted mouth opening, our case highlights the need for evaluation of the coronoid process, which is usually ignored during routine radiographic examination. The report also highlights the miniscule incidence of this condition in the available literature.