Collision Tumor (An enigma): A Review Article

A BSTRACT Collision tumor is the co-existence of two adjacent but histologically different neoplasms, without intermixture of cell types in the same tissue. They are commonly reported in organs like gastrointestinal tract, lung, skin, adrenals, lymph nodes, and uterus. However, they are relatively rare in the ovary. We report here a case of 70-year-old Indian married postmenopausal woman who presented with a Right Ovarian Mass. Comorbidity of Hyperobstructive Cardiomyopathy (HOCM). The patient underwent Staging Laparotomy for a Right Ovarian Mass. Intra-operatively tumor was a woody hard mass with clinical suspicion of fibroma/thecoma and frozen section confirmed it to be fibroma of the ovary. However, on final histopathology, the surprise element of collision tumor came into the light when the Pathologist reported it to be a combination of serous cystadenoma and fibroma in the same tumor. Her post-operative recovery was uneventful. Collision tumor is mindboggling/collision of minds for the pathologist to give the final histopathology. However, prognosis depends on the components present in the tumor. Hence, it is very essential for histopathologists, surgeons and oncologists to be aware of such entities for appropriate treatment strategies.