Collision of Primary Malignant Neoplasms on the Skin: The Connection between Malignant Melanoma and Basal Cell Carcinoma

Abstract

Several studies have reported the association of cutaneous malignant melanomas (MM) with carcinomas. Collision malignancies cases from our files were retrieved. Among a series of 78,000 primary cutaneous cancers, 11 were collision tumors of MM with basal cell carcinoma and 106 were basosquamous carcinomas while no association was found between MM and squamous cell carcinomas. It is concluded that coexisting and confluent malignancies of the skin might not always be a random event.

Collision of Squamous-Cell Carcinoma with Melanoma in situ in a Child with Xeroderma pigmentosum

“…Most previous case reports of cutaneous collision tumors have involved an association of malignant melanoma and basal cell carcinoma, and squamous-cell carcinoma and basal-cell carcinoma [4, 5, 6, 7]. Only a single case report in the literature describes a collision tumor between squamous-cell carcinoma and melanoma.…”

A Case of Two Synchronous Cutaneous Collision Tumors

“…The first case described the collision of BCC and MM was in 1983 by Kao in the Annual meeting of the American Society of Dermatopathology and the greatest information about the incidence of these tumors had been reported by Pieard and et al (7). When Pieard et al, examined 78.000 excision materials, they found 11 collision tumors, including BCC and MM (7). Although, different combinations of both SCC and BCC with other tumors were mentioned in the literature, there were no co-existence of SCC and BCC in the literature.…”

Collision tumor of the rectum: A case report of metastatic gastric adenocarcinoma plus primary rectal adenocarcinoma

“…Malignant neoplasms originating from two or more distinct topographic organs may form a collision tumor. A possible explanation for this is field cancerization, which occurs due to long-term exposure to carcinogens, whereby multiple carcinogenic transformations give rise to genetically unrelated secondary primary tumors with independent mutations [2,3] and thus, the chance of tumor collision may be increased. However, there is no explanation for the occurrence of many collision tumors.…”