BENIGN, BORDERLINE, AND WELL-DIFFERENTIATED MALIGNANT INTESTINAL MUCINOUS TUMORS OF THE OVARY - A CLINICOPATHOLOGICAL, HISTOCHEMICAL, IMMUNOHISTOCHEMICAL, AND NUCLEAR QUANTITATIVE STUDY OF 57 CASES

Mucinous ovarian tumors are still a subject of controversy because the y can show either intestinal or endocervical differentiation. Morpholo gic distinction between borderline and malignant tumors is sometimes d ifficult, and their clinical behavior has not been definitively ascert ained. We selected 10 mucinous cystadenomas (MCAs), 32 intestinal muci nous borderline tumors (IMBTs), and 15 well-differentiated mucinous ca rcinomas (MCCs), all with goblet cells, at least focally. In all cases , we studied the clinicopathologic features, mucin content, intermedia te filament expression, and some nuclear quantitative features, namely , the volume-corrected mitotic index (M/Vi), percentage of nucleolated nuclei, mean number of nucleoli per nucleus, percentage of nucleoli t ouching the nuclear membrane, and mean nuclear area. The quantitative nuclear study included cytometric DNA analysis and the results were ex pressed as relative mean ploidy value (RMPV) and as diploid-tetraploid or aneuploid histograms. The results of the quantitative study were e valuated statistically. All patients had stage IA tumors, had received surgical therapy only, and were alive and well after a follow-up of m ore than 5 years. Light microscopic examination revealed that destruct ive stromal invasion was not present in any MCCs and that IMBTs and MC Cs were easily recognizable using the Hart and Norris criteria, later expanded by Hart, Mucin histochemistry and intermediate filament immun ohistochemistry failed to detect substantial differences between the d iagnostic categories. DNA analysis demonstrated an increase in aneuplo id tumors going from IMBTs to MCCs, but these differences were not sta tistically significant. On the other hand, nuclear quantitative morpho logy showed significant differences among the three groups of tumors f or all features considered. Forward stepwise discriminant analysis hig hlighted that MCAs, IMBTs, and MCCs were contiguous but different cate gories. These data support the separation of IMBTs and MCCs into morph ologically different categories as underlined by the results of quanti tative nuclear morphologic analysis. The favorable outcome of all pati ents confirms the excellent prognosis of stage I IMBTs and suggests th at well-differentiated MCCs without destructive stromal invasion at st age IA could be assimilated, in terms of prognosis and therapy, into s tage I IMBTs.