1. Multiple adenocarcinomas and synchronous leiomyosarcoma of the colon: a case report M.C. De Nisi, C.Maggiore, C.Minacci, M.Stumpo, M.L. Palmeri, L. Pergola, A. Genovese, A. Rossi. U.O.C. Anatomia Patologica-Grosseto Congresso Nazionale SIAPEC-IAP 7-9 settembre 2009-Firenze

2. CLINICAL PRESENTATION  73 YEAR OLD MAN WITH OBSTRUCTIVE NEOPLASM  NO CANCER PREDISPOSITION SYNDROME  NO PREGRESS NEOPLASM REFERRED

3. GROSS EXAMINATION 8 POLYPOID TUMOURS RANGING FROM 0,3 TO 5 CM:  THE LARGEST NEOPLASM WAS COMPOSED OF A POLYPOID COMPONENT AND A HARD INFILTRATING ONE;  THE REMAINING LESIONS WERE POLYPOID ONLY

4. MICROSCOPIC EXAMINATION  SIX SMALLER POLYPS WERE TUBULO- VILLOUS ADENOMAS  THE SECOND LARGEST NEOPLASM WAS AN ADENOCARCINOMA G2 - pT3 N0 Mx  THE LARGEST LESION WAS COMPOSED OF TWO DIFFERENT TUMOURS: A TYPICAL ADENOCARCINOMA AND A LOW GRADE LEIOMYOSARCOMA

5. DIFFERENTIAL DIAGNOSIS ???? COLLISION TUMOURS OR ADENOCARCINOMA WITH SARCOMATOID DIFFERENTIATION ???

6. LITERATURE ➢ A case of rectosigmoid carcinoma with concurrent, but distinct, rectal leiomyosarcoma(Alfonso A.E. Et all: Synchronous leiomyosarcoma and adenocarcinoma of the rectum: report of a case and rewiew of the literature. Dis. Colon Rectum, 18: 228-231, 1975) ➢ A case of leiomyosarcoma developing in the colostomy of a patient treated for rectal adenocarcinoma (Witz M et all.: Methachronous leiomyosarcoma in colostomy after abdominoperitoneal resection for rectal carcinoma.J. Surg. Oncol.,32:200-202, 1986)

7. LITERATURE  Only one carcinosarcoma with adenosquamous, osseus, cartilaginous and non specific spindle cell differentiation (Weidner N.: Carcinosarcoma of the colon. Report of a unique case with light and immunohistochemical studies. Cancer, 58: 1126-1130, 1986)  Only one case of neoplasm exibiting two distinct components, one epithelial and one sarcomatous whose cells reacted with a monoclonal antibody agaist actin (Di palma S. et all: Association of adenocarcinoma and leiomyosarcoma of the sigmoid colon. A case report. Tumori, 77: 175-177, 1991)

8. DEFINITION ➢ COLLISION TUMOR: a tumour with a distinct boundary between two different components (i.e. adenocarcinoma and sarcoma) (WHO 2000) ➢ CARCINOSARCOMA: malignant tumours containing both carcinomatous and heterologous mesenchymal elements (WHO 2000)

9. MORPHOLOGY THE NEOPLASM WAS COMPOSED OF A DISCRETE SARCOMATOUS AND GLANDULAR COMPONENT WITH NO MORFOLOGICAL “TRANSITION” BETWEEN THE TWO DIFFERENT NEOPLASTIC TISSUES

10. MORPHOLOGY 4x 40x

11. IMMUNOPHENOTYPE  THE ADENOCARCINOMATOUS CELLS WERE: AE1AE3+;CEAP+;Vimentin; Actin-; Desmin-.  THE SARCOMATOUS CELLS STAINED DIFFUSELY AND STRONGLY WITH Vimentin, Desmin and Actin; NEGATIVE FOR Cytokeratins, CEA-P and CD117.

12. IMMUNOPHENOTYPE AE1AE3 CEA-P Vimentin

13. CONCLUSION MORPHOLOGICAL AND IMMUNOISTOCHEMICAL RESULTS RULED OUT THE DIAGNOSIS OF CARCINOSARCOMA OR METAPLASTIC ADENOCARCINOMA WHILE SUPPORTED THE HYPOTHESIS OF TWO DIFFERENT NEOPLASTIC CLONES

14. DIAGNOSIS LOW GRADE LEOMYOSARCOMA SYNCHRONOUS WITH TWO INFILTRATING ADENOCARCINOMAS AND MULTIPLE ADENOMAS

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