A tumour with a neuroendocrine and papillary serous component: two or a pair?

van Eeden, S; Nederlof, P M; Taal, B G; Offerhaus, G J A; van Velthuysen, M-L F

doi:10.1136/jcp.55.9.710

A tumour with a neuroendocrine and papillary serous component: two or a pair?

¹Academic Medical Center, Department of Pathology, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands
²Department of Pathology, Het Nederlands Kankerinstituut/Antoni van Leeuwenhoek Ziekenhuis, Plesmanlaan 121, 1066 CX Amsterdam, The Netherlands
³Department of Gastroenterology, Het Nederlands Kankerinstituut/Antoni van Leeuwenhoek Ziekenhuis

Correspondence to:  Dr S van Eeden, Department of Pathology, Academic Medical Center, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands;  S.vaneeden{at}amc.uva.nl

Accepted 15 April 2002

Abstract

Aims: To examine the clonal origin of a tumour, made up of a neuroendocrine component and a papillary serous component by comparing the pattern of loss of heterozygosity (LOH) and the immunohistochemical protein expression of both components.

Methods/Results: A 70 year old woman, known to have a metastasised neuroendocrine carcinoma, underwent resection of the distal part of the ileum because of obstruction by a mesenterial mass. The macroscopically homogeneous mesenterial mass consisted histologically of an admixture of a neuroendocrine component and a papillary serous carcinoma. Loss of heterozygosity (LOH) analysis of both components with a panel of 15 polymorphic microsatellite markers showed a distinctive pattern of LOH, and both components showed LOH on chromosome 4q and 17, but involving different alleles at the same locus. Moreover, both components showed different immunohistochemical staining patterns for neuroendocrine markers, cytokeratin 7, carcinoembryonic antigen, and CA125.

Conclusion: Both LOH analysis of the neuroendocrine and papillary serous components of this tumour and the immunohistochemical profile of both components are consistent with a different clonal origin. The tumour is probably a collision tumour, in which the papillary serous carcinoma must have been of peritoneal origin because necropsy revealed a normal uterus and normal ovaries.