collision tumor

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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.
Farlex Partner Medical Dictionary © Farlex 2012
(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
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.
References in periodicals archive ?
Cutaneous collision tumors: an analysis of 69 cases and review of the literature.
Imaging and management of a small cell lung cancer metastasis/adrenal adenoma collision tumor: A case report and review of the literature.
The coexistence of neoplasms was found more frequently in women and at a younger age.[sup][2] The literature reported that RCCs that coexisted with AMLs mostly were double primary tumors, and more rarely collision tumor. There are only six case reports about AML and RCC coexisting in the same tumor mass.
The present case had an admixture of DA component with conventional ameloblastoma tissue, which is why we consider that it was a modulated tumor rather than a collision tumor.
Of note, the term basosquamous carcinoma is sometimes used synonymously for metatypical BCC but may also describe collision tumors between BCC and squamous cell carcinoma; therefore, this term is best accompanied by clarification of the intended definition.
A diagnosis of collision tumor of neurofibroma with chondroid syringoma was made.
For the collision tumor theory to hold would require an unlikely occurrence-namely, that multiple, sequential carcinogenic events in two or more independent cell types would result in a malignant transformation of each.
The possibility of a collision tumor was considered but was subordinated primarily because of the intimate association of the various elements of the lesion and the lack of any other known malignancies.
In the case of the patient with the collision tumor, the grossly apparent mass (a well-demarcated 1.2 x 1.1 x 1.0-cm firm area within a 3.5 x 2.5 x 1.5-cm excisional biopsy) was predominantly composed of a 1.0-cm GCT.
Even if we consider this suggestion to be true, the question of whether the tumor is a malignant meningioma or a collision tumor still remains unanswered.
The "collision tumor" theory suggests that 2 distinct malignancies coexist and then collide and intermingle.

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