collision tumor

Also found in: Dictionary, Thesaurus, Encyclopedia.

col·li·sion tu·mor

two originally separate tumors, especially a carcinoma and a sarcoma, that appear to have developed by chance in close proximity, so that an area of mingling exists.
See also: carcinosarcoma.

collision tumor

Etymology: L, cum, together with, laedere, to strike
a tumor formed when two separate growths, developing close to each other, join. See also carcinoma.
(1) A generic term for the extremely rare merging of 2 originally separate—primary—tumours from 2 organs, most often seen at the oesophagogastric junction, where a squamous cell carinoma of oesophageal origin collides with a gastric adenocarcinoma; diagnosis of a collision tumour requires that the 2 tumours be histologically distinct
(2) A neuroendocrine (carcinoid) tumour characterised by discrete populations of neoplastic neuroendocrine cells and glands

collision tumor,

n See tumor, collision.
Enlarge picture
Collimation of a radiographic beam.
References in periodicals archive ?
6-12,15) Our patient was diagnosed with concurrent mammary carcinoma and MALT lymphoma, presenting as collision tumor, infiltrating each other and occupying a single tumor in the same breast.
31,32) Several reports have described GCTs in the breast to occur either in close proximity to an invasive adenocarcinoma (33,34) (within 2 cm) or as a component of a collision tumor with adenocarcinoma invading into the GCT component.
Based on previous reports on the positive staining of the clear cell type of RCC for CA IX, (18) we performed immunostains for this carbonic anhydrase on our collision tumor.
Subsequently, we used the staining properties of the urothelial and prostate carcinomas to verify a collision tumor in the lymph node.
A Case Report of Unusual Collision Tumors With Review of the Literature
The distribution of immunostaining correlated completely with the histologic distinction between the prostatic and mammary carcinoma components in the collision tumor.
Gliosarcoma is a mixed tumor containing both malignant glial and mesenchymal tissues intermixed, unlike in the collision tumor.
All of the theories seem to point to 2 basic mechanisms, which were initially proposed by Meyer in 1919: collision tumor or combination tumor.
double dagger]) One case was a collision tumor with malignant lymphoma.
The term basosquamous carcinoma has been used by some to describe BCC with squamous metaplasia as well as a prominent stromal proliferation, (17,18) although others apply the same name to collision tumors in which a typical BCC is identified adjacent to SCC.
7), (8) Meyer (1920) classified carcinosarcomas into three histogenetic groups: 1) collision tumors in which carcinoma and sarcoma arise simultaneously in proximity and subsequently invade each other, 2) combination tumors in which both tumors derive from pluripotent cells, and 3) composition tumors in which the components arise from the same tissue.

Full browser ?