Mucinous tumors of the ovary: a clinicopathologic study of 196 borderline tumors (of intestinal type) and carcinomas, including an evaluation of 11 cases with 'pseudomyxoma peritonei'

Advanced-stage serous borderline tumors of the ovary: a clinicopathological study of 49 cases

There is controversy about patient outcomes and pathological parameters of prognostic significance in patients with stage II or stage III ovarian serous borderline tumors. Forty-nine cases of stage II and III ovarian serous borderline tumors were identified on review of the medical records at Vancouver Hospital and British Columbia Cancer Agency for the period from 1979 to 1996. Pathological features assessed included presence of micropapillary architecture, tumor cell DNA content (ploidy), and characteristics of the extraovarian implants, including invasiveness and mitotic activity. Clinical follow-up information (3-17 years of follow-up) was obtained for 48 patients. Fifteen patients had stage II tumors and 34 had stage III tumors. Fourteen patients experienced tumor recurrence 1 to 8 (mean 3.5) years after presentation and of these, six patients died of disease (2, 3, 4, 7, 10, and 11 years after presentation). Patients with gross residual disease, as assessed by the surgeon, more frequently experienced a recurrence compared with patients without gross residual disease, but this difference did not reach statistical significance (0.05<p<0.1). The patients who died of disease all had stage III tumors. Patients with invasive implants had a significantly worse outcome than patients with noninvasive implants (p<0.005). Other pathological features (ploidy, micropapillary architecture, invasiveness of implants, mitotic activity of implants) were not significantly predictive of tumor recurrence or death. No single pathological feature or combination of features was present in all patients who subsequently died of disease. In conclusion, the prognosis for patients with advanced-stage serous borderline tumors in this population-based study is very favorable, with only six patients ultimately dying of progressive disease. The combination of stage (stage III) and invasiveness of extraovarian implants identifies a small subset of patients with advanced-stage serous borderline tumors with a significantly worse prognosis, who may benefit from adjuvant therapy.

Ovarian mucinous and mixed epithelial carcinomas of mullerian (endocervical-like) type: a clinicopathologic analysis of four cases of an uncommon variant associated with endometriosis

The epithelial cells of ovarian mucinous carcinomas may sometimes appear similar to those of gastrointestinal or endocervical mucinous carcinomas, but most are composed of cells that do not suggest any particular derivation. We report four cases of mucinous ovarian carcinoma in which the cells were entirely or almost entirely endocervical-like. The patients' ages were 34, 43, 44, and 50 years. Two patients had bilateral tumors confined to the ovaries at initial staging; both also had synchronous endometrial carcinomas of the mucinous type. The two other patients had unilateral tumors, both with invasive metastases in the pelvis and abdomen at initial staging. In one of the latter cases a mullerian (endocervical-like) mucinous borderline tumor (MMBT) of the opposite ovary had been removed 5 years earlier, and in this case and two other cases the ovarian carcinomas had foci resembling MMBT, suggesting that they may be an invasive counterpart to these tumors. The six tumors ranged from 4 to 19 cm; five were grossly cystic with papillary or solid areas, and one was entirely solid. They were composed of closely packed glands, cysts, and cysts containing complex papillae. There was abundant intraglandular and intracystic mucin. The epithelial cells were well differentiated with infrequent mitoses and most were tall with mucinous cytoplasm resembling normal endocervical glandular cells. In three tumors there also were round to polygonal cells with eosinophilic cytoplasm; endometrioid foci were present in three tumors and a squamous focus was present in one. One tumor had a focally infiltrative growth pattern with a desmoplastic stromal reaction; the remaining five tumors had an exclusively confluent (expansile) pattern of invasion. Endometriosis was present in residual ovarian tissue adjacent to four tumors in three patients and had marked epithelial proliferation in three. All patients were treated postoperatively with chemotherapy and were without clinical recurrence with follow-up intervals of 8 months, 1.2 years, 2.9 years, and 3.8 years. By immunohistochemical analysis the neoplastic epithelium was positive for estrogen and progesterone receptor proteins, vimentin, and cytokeratin 7, and negative or only focally positive for carcinoembryonic antigen and cytokeratin 20, a profile that differs from that of the usual mucinous ovarian carcinoma and is supportive of a mullerian derivation. As with MMBTs, there was a strong association with endometriosis, and these tumors likely arise from endometriosis, possibly through an MMBT precursor in some cases. To better understand their clinicopathologic features and pathogenesis, this uncommon variant should be separated from the usual type in future studies of mucinous carcinomas of the ovary.

Pseudomyxoma peritonei is a disease of MUC2-expressing goblet cells

Pseudomyxoma peritonei, a syndrome first described by Karl F. Rokitansky in 1842, is an enigmatic, often fatal intra-abdominal disease characterized by dissecting gelatinous ascites and multifocal peritoneal epithelial implants secreting copious globules of extracellular mucin. Although past interest in the syndrome has focused on the questions of the site of origin (appendix versus ovary), mechanisms of peritoneal spread (multicentricity, redistribution phenomenon, or metastasis), and the degree of malignant transformation present (adenoma, borderline tumor, or carcinoma), another important question is the mechanism behind the accumulation of extracellular mucin, the real cause of the disease's morbidity and mortality irrespective of the site of origin, mechanism of peritoneal spread, or transformed status of its epithelium. Taking advantage of the recently cloned human mucin genes, we decided to investigate this question. Our studies revealed that pseudomyxoma peritonei is a disease of MUC2-expressing goblet cells. These cells also express MUC5AC but the latter mucin is not specific for pseudomyxoma peritonei. MUC2 expression accounts for the voluminous deposits of extracellular mucin (mucin:cell ratios exceeding 10:1) and distinguishes pseudomyxoma peritonei secondarily involving the ovary from primary ovarian mucinous tumors with peritoneal implants. Because mucinous tumors of the appendix similarly express MUC2, the MUC2 expression profile also supports an appendiceal rather than ovarian origin for pseudomyxoma peritonei. Increased steady-state mRNA is observed in pooled cases of pseudomyxoma peritonei but does not occur on the basis of gene rearrangement or gene amplification. Primary epithelial cell cultures obtained from pseudomyxoma peritonei express MUC2 whose levels can be epigenetically regulated. These lines up-regulate MUC2 expression in response to both methylation inhibition by 5-azacytidine and exposure to Pseudomonas aeruginosa lipopolysaccharide, both of whose effects can be suppressed by genistein pretreatment. Both immunocytochemical as well as in situ hybridization studies with ancillary digital image analysis reveal that MUC2 expression in cases of pseudomyxoma peritonei is independent of the degrees of malignant transformation that are present and, in fact, reflects the constitutive levels of expression observed in normal goblet cells of the appendix. Extracellular mucin accumulates dramatically in pseudomyxoma peritonei because the number of MUC2-secreting cells dramatically increase and because this MUC2 has no place to drain. These studies suggest that pseudomyxoma peritonei should be regarded as a disease of MUC2-expressing goblet cells whose MUC2 expression might be susceptible to pharmacological targeting.

CT in pseudomyxoma peritonei: a review of 17 cases

AIM

To describe the computed tomography (CT) findings in pseudomyxoma peritonei.

MATERIALS AND METHOD

Two observers independently and retrospectively reviewed the CT images of 17 consecutive patients (nine women, eight men, mean age 53 years) with histologically proven pseudomyxoma peritonei.

RESULTS

Six patients had small volume disease where pseudomyxoma peritonei was present in focal collections in the peritoneal cavity. Eleven had large volume disease that completely, or almost completely, filled the peritoneal cavity. Pseudomyxoma peritonei is characterized by low attenuation mucinous ascites on CT. Areas of high attenuation, septae and calcification are seen more commonly within it as the volume of disease increases. The pattern of accumulation of pseudomyxoma peritonei follows the normal flow of peritoneal fluid. It initially seeds at sites of relative stasis and as large volume disease develops it fills the remaining spaces in the peritoneal cavity and pressure effects dominate imaging. Pseudomyxoma peritonei may extend into hernial orifices or the pleural cavity.

CONCLUSION

Pseudomyxoma peritonei is difficult to diagnose clinically. However, the pattern of accumulation of disease is predictable and can be recognized on CT.

Mucinous and nonmucinous appendiceal adenocarcinomas: different clinicopathological features but similar genetic alterations

The genetic alterations of appendiceal carcinomas have not been reported in detail. We studied the clinicopathological factors and genetic alterations including microsatellite instability, p53 overexpression, and mutations of the K-ras proto-oncogene of 30 appendiceal adenocarcinomas, consisting of 23 mucinous and 7 nonmucinous carcinomas. Sixteen (70%) mucinous carcinomas presented with pseudomyxoma peritonei, but 6 of 7 (86%) nonmucinous carcinomas presented with appendicitis (P =.002). All carcinomas were microsatellite stable, and p53 overexpression was present in only 1 of 30 (3%) carcinomas. K-ras mutation was present in 11 of 20 (55%) carcinomas, including 8 of 16 (50%) mucinous and 3 of 4 (75%) nonmucinous carcinomas. The mean survival of patients with mucinous carcinomas was 26 +/- 19 months compared with 13 +/- 9 months for patients with nonmucinous carcinomas (P =.0002). Our findings suggest that mucinous and nonmucinous carcinomas of appendix have similar genetic alterations, but different clinical presentation and prognosis.