Peritoneal papillary serous carcinoma: study of 15 cases and comparison with stage III-IV ovarian papillary serous carcinoma

Narrative review on serous primary peritoneal carcinoma of unknown primary site: four questions to be answered

Serous peritoneal papillary carcinoma (SPPC) represents a particular cancer of unknown primary (CUP) entity that arises in the peritoneal surface lining the abdomen and pelvis without a discriminative primary tumor site. In this review, we discuss the validity of SPPC as a distinct entity. Clinically, patients with SPPC are older, have higher parity and later menarche, are more often obese and probably have poorer survival compared to those with primary ovarian cancer. Pathologically, SPPC is more anaplastic and multifocal, unlike primary ovarian cancer which is commonly unifocal. Biologically, it presents a higher expression of proliferative signals and similar cell cycle and DNA repair protein expression. These differences hint towards SPPC and primary ovarian cancer being as a spectrum of disease. Patients with SPPC are traditionally managed similarly to stage III–IV ovarian cancer. The recommended approach integrates aggressive cytoreductive surgery, hyperthermic intraperitoneal chemotherapy, and systemic chemotherapy to remove the macroscopic tumor, eradicate the microscopic residual disease, and control the microscopic metastasis. However, the available evidence lacks proper randomized or prospective studies on SPPC and is limited to retrospective series. The diligent identification of SPPC is warranted to design specific clinical trials that eventually evaluate the impact of the new therapeutics on this distinct entity.

Clinico-pathological outcomes after total parietal peritonectomy, cytoreductive surgery and hyperthermic intraperitoneal chemotherapy in advanced serous papillary peritoneal carcinoma submitted to neoadjuvant systemic chemotherapy- largest single institute experience

INTRODUCTION

Serous papillary peritoneal carcinoma (SPPC) is a rare clinical entity. Based on the understanding of the pattern of spread, its multifocality, polyclonality and the high frequency of diffuse, widespread peritoneal metastasis, a robust rationale for cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for SPPC exists. Herein we report the clinical outcomes of SPPC patients treated with neoadjuvant systemic chemotherapy (NACT) followed by CRS including total parietal peritonectomy and HIPEC.

METHODS

Clinico-pathological data of 22 patients of serous papillary peritoneal carcinoma (SPPC) was retrospectively analyzed from a prospectively maintained database from June 2000 to July 2017. Patients were treated with CRS, total parietal peritonectomy and HIPEC with cisplatin (42 mg/L of perfusate) and doxorubicin (15 mg/L of perfusate) after NACT. Survival curves were calculated from the date of surgery.

RESULTS

22 patients underwent CRS, total parietal peritonectomy and HIPEC. The median age was 62 years (Range 47-72). On histological evaluation, 18/30 (60%) parietal peritonectomy specimens showed microscopic disease, when no disease was evident macroscopically at surgical exploration. Grade III-IV surgical complications were recorded in 4/22 (18%) patients. There was no postoperative mortality. At a median follow up of 12 months, the five-year overall survival (OS) was 64.9%. The median OS was not reached. Median progression-free survival was 32.9 months and progression-free survival at 5 years was 33.2%.

CONCLUSION

CRS with total peritonectomy + HIPEC after NACT, presents as a promising treatment modality for SPPC, and could be associated with good survival results in patients with SPPC.

Clinical characteristics of primary peritoneal carcinoma patients: a single-institution experience involving 8 patients

Primary peritoneal carcinoma (PPC) is treated similarly to advanced epithelial ovarian carcinoma (aEOC); however, the standard approach for the management of PPC is controversial. The objective of this study was to evaluate the clinical features and prognosis of those patients. A retrospective analysis was performed of eight patients with PPC between January 2008 and December 2015. Clinicopathologic parameters, the diagnostic modality, treatment, and oncologic outcome were analyzed. The median age at the time of diagnosis was 72.5 years (range: 55–79), with a median follow-up of 26.5 months (range, 5–74). Most of the PPC developed with carcinomatosis peritonei involving ascites, while some cases developed sporadically in the peritoneal or extraperitoneal cavity without ascites. The most common initial symptom was abdominal fullness, and other symptoms were inguinal tumor, paralysis of the extremities, and respiratory disorder. The preoperative CA125 value was elevated in all patients. In four patients who did not undergo primary surgery, the final diagnoses were determined by the ascites cytology and radiological image. Initial or interval debulking surgery was performed in only two patients. All patients were treated with paclitaxel or docetaxel plus carboplatin. Five showed a complete response (CR), and one showed a partial response (PR). Among the five patients with CR, the median progression-free and overall survival periods were 15 (12–26) and 41.5 (32–74) months, respectively. Three patients without carcinomatosis peritonei showed a relatively favorable prognosis. The management of PPC is generally consistent with that of aEOC; however, in atypical cases, the treatment method should be considered individually.

Demographic clinical and prognostic characteristics of primary ovarian, peritoneal and tubal adenocarcinomas of serous histology--a prospective comparative study

OBJECTIVES

Invasive serous adenocarcinomas may present as primary ovarian (POC), primary fallopian tube (PFC) or primary peritoneal (PPC) carcinomas. Whether they are variants of the same malignancy or develop through different pathways is debated.

METHODS

Population-based prospectively collected data on POC (n=1443), PPC (n=268) and PFC (n=171) cases was obtained from the Danish Gynecological Cancer Database (2005-2013). Chi-square, Fisher's or Wilcoxon-Mann-Whitney test, multivariate logistic regression, Kaplan-Meier and multivariate Cox-regression were used as appropriate. Statistical tests were 2-sided. P-values of <0.05 were considered statistically significant.

RESULTS

PPC cases were older (P<0.0001), had a later age at menarche (P=0.02), a higher percentage were multi-parous (≥two children vs. no children) OR 1.70 (1.01-2.49) and both PPC and PFC tended to have a higher BMI (>35 vs. >18.5-25) than POC cases. PFC cases were diagnosed in earlier stages (P<0.001). In advanced stages a lower proportion had preoperative carcinosis or ascites, and a higher percentage had macro-radical surgery or lymphadenectomy compared to POC. In contrast, more PPC cases had post-operative carcinosis; whereas a lower proportion had lymphadenectomy or macro-radical surgery compared to POC. PPC had a significantly lower overall survival than POC, HR=1.24 (1.04-1.47).

CONCLUSION

We found differences in risk pattern profiles among the three groups, especially for PPC. Furthermore, the severity of stage specific disease differed significantly according to location, resulting in a lower overall survival for PPC. These differences warrant further research to determine to what extent PPC is a distinct disease entity.

Prognosis for advanced-stage primary peritoneal serous papillary carcinoma and serous ovarian cancer in Taiwan

OBJECTIVE

To compare the prognosis of patients with advanced-stage primary peritoneal serous papillary carcinoma (PSPC) or papillary serous ovarian cancer (PSOC).

MATERIALS AND METHODS

This was a retrospective case-control study and included two study groups: one with stage III/IV PSPC (n = 38) patients and the other with PSOC (n = 53) patients. Patients were matched for histologic subtype (serous tumor), tumor stage, tumor grade, residual disease at the end of debulking surgery (primary or interval), and age (±5 years).

RESULTS

Mean age was significantly greater for patients with PSPC (63.03 ± 11.88 years) than for patients with PSOC (55.92 ± 12.56 years, p = 0.008). Optimal debulking surgery was performed initially in 71.9% of PSPC patients and 66.0% of PSOC patients. In addition, 93.9% of PSPC patients and 92.3% of PSOC patients were treated with platinum-paclitaxel chemotherapy. The frequency of high-grade tumors was significantly higher in the PSPC (100%) than in the PSOC group (68.3%; p < 0.001). Progression-free survival (PFS) was similar in the PSPC [median 12 months, 95% confidence interval (CI) 7.3-16.7] and PSOC groups (median 16.7 months, 95% CI 12.9-20.4; p = 0.470). Overall survival was shorter in the PSPC (median 62 months, 95% CI 19.6-104.4) than in the PSOC group (median 77.5 months, 95% CI 69.7-85.2; p = 0.006, log-rank statistic).

CONCLUSION

PFS was similar for advanced-stage PSPC and PSOC patients. Since the PSPC patients tended to be older and have more high-grade tumors, OS was shorter for PSPC than for POSC patients. Thus, management of the two types of cancer should not differ.

Paclitaxel plus Carboplatin Chemotherapy for Primary Peritoneal Carcinoma: A Study of 22 Cases and Comparison with Stage III-IV Ovarian Serous Carcinoma

The aim of this study was to assess the clinical characteristics and outcome of patients with either primary peritoneal carcinoma (PPC) or ovarian serous carcinoma (OSC) treated with paclitaxel plus carboplatin chemotherapy. We retrospectively identified 22 PPC patients and 55 stage III–IV OSC patients treated between 2002 and 2007. After exploratory laparotomy, all patients received paclitaxel and carboplatin every 3 weeks, with the goal of optimal cytoreduction. There were no statistically significant differences between the PPC and OSC groups with regard to tumor stage, residual tumor after debulking surgery (initial or interval), serum cancer antigen (CA) 125 levels at diagnosis, and completion of first-line chemotherapy. The progression-free survival (PFS) durations were 12.7 months (95% CI, 6.3–18.5) in the patients with PPC and 15.9 months (95% CI, 13.3–18.5) in those with OSC (p = 0.016). However, the median survival durations were 26.5 months (95% CI, 14.6–38.3) in the patients with PPC and 38 months (95% CI, 23.8–53.8) in those with OSC (p = 0.188). Survival was longer for all patients whose CA125 levels normalized to 26 U/ml during and after treatment. Overall survival (OS) of the patients with PPC was similar to that of the patients with OSC, suggesting that management for advanced-stage OSC would be similar to that for PPC. The combination of optimal debulking with paclitaxel plus carboplatin chemotherapy may offer patients the most effective treatment. The CA125 nadir after cytoreductive surgery can be considered a prognostic factor for OS and PFS in patients with PPC.

Serous papillary peritoneal carcinoma: unknown primary tumour, ovarian cancer counterpart or a distinct entity? A systematic review

INTRODUCTION

Serous peritoneal papillary carcinoma (SPPC), though managed according to ovarian cancer therapeutic principles, has been variably considered as an ovarian cancer counterpart, a peritoneal malignancy with distinct characteristics or a cancer of unknown primary (CUP).

PATIENTS AND METHODS

We systematically reviewed all publications studying molecular pathophysiology, clinical presentation, management and outcome of at least 10 patients with SPPC from 1980 to 2008 in anglophone medical journals and critically analysed the data.

RESULTS

Molecular profiling of CUP was performed in eight papers reporting on 211 patients with stage III/IV SPPC by means of immunohistochemistry or PCR-based assays. Twenty-five clinical series, mostly retrospective, reported management and outcome of 579 patients with SPPC, in several cases matched to advanced ovarian cancer controls. Though we did not identify statistically significant differences in molecular biology, clinical presentation, management and outcome of SPPC and ovarian cancer cases, some subtle differences emerged: patterns of loss of heterozygosity at several chromosomal loci differed from those seen in ovarian cancer, while the overexpression of the HER2 oncogene was encountered more often. Serous peritoneal tumours affected older patients and were more frequently multifocal or exhibited virulent clonal expansion in metastatic sites. Diffuse micronodular spread formed a high total load of malignancy in omental, peritoneal surfaces, difficult to debulk optimally. Despite effective chemotherapeutic cytoreduction and occasional long-term remissions, SPPC patients survived 2-6 months less than ovarian cancer patients.

CONCLUSIONS

Patients with SPPC should not be classified in the poor-risk CUP category, in view of the therapeutic and prognostic differences. Still, the assimilation of the SPPC entity by ovarian cancer hindered further research into its genotypic and phenotypic characteristics that may differ from ovarian cancer. Subgroup analyses of large ovarian cancer trials may shed light in this issue.

Subdividing ovarian and peritoneal serous carcinoma into moderately differentiated and poorly differentiated does not have biologic validity based on molecular genetic and in vitro drug resistance data

Serous carcinoma of the ovary has been traditionally graded as well-differentiated, moderately differentiated, and poorly differentiated (ie, a 3-tier system). A new 2-tier system grades serous carcinomas into low or high grade. Recent morphologic and molecular studies have shown that invasive well-differentiated serous carcinoma, referred to by us as "invasive low-grade micropapillary serous carcinoma," is clearly distinct from high-grade serous carcinoma from the standpoint of pathogenesis and clinicopathologic features. As high-grade serous carcinoma is histologically heterogeneous, the goal of this study was to determine, based on molecular and drug resistance data, whether further subclassification of high-grade serous carcinomas into additional grades (moderately and poorly differentiated) has biologic validity. One hundred eleven ovarian and peritoneal high-grade serous carcinomas further subclassified as moderately and poorly differentiated types using the International Federation of Gynecology and Obstetrics (FIGO) grading system were analyzed for TP53 mutations and in vitro extreme drug resistance to 10 chemotherapeutic drugs. Seventy-six and 35 cases were subclassified as moderately and poorly differentiated, respectively. A TP53 mutation was present in 84% of moderately and 70% of poorly differentiated types of high-grade serous carcinomas, respectively (P=0.21), and there were no significant differences in the frequency of extreme drug resistance for each of the 10 drugs tested (P values ranging from 0.14 to >0.99). Although additional investigation is warranted, this study suggests that subclassification of high-grade serous carcinoma into moderately and poorly differentiated is not relevant. Accordingly, they can be simply classified as high-grade serous carcinoma.

Immunohistochemical identification of primary peritoneal serous cystadenocarcinoma mimicking advanced colorectal carcinoma: a case report

Primary peritoneal cystadenocarcinoma is a rare tumor of similar histogenic origin as primary ovarian carcinoma. We present a case of primary peritoneal serous cystadenocarcinoma mimicking advanced colorectal cancer in a 68 yr-old African American female. Radiology, endoscopy and cytology yielded only inconclusive findings. Immunohistochemical analysis of percutaneously obtained ascitic fluid provided a correct diagnosis of primary peritoneal cystadenocarcinoma. The discovery of serous ascites at the time of laparotomy confirmed a diagnosis of primary peritoneal serous cystadenocarcinoma. Final surgical pathology reconfirmed the diagnosis of primary peritoneal cystadenocarcinoma. This case demonstrates the utility of immunohistochemistry for accurately diagnosing patients with inconclusive findings in the setting of peritoneal carcinomatosis and primary peritoneal cystadenocarcinoma.

CT and MRI of adnexal masses in patients with primary nonovarian malignancy

OBJECTIVE

The purpose of this pictorial essay is to review the differential considerations when an adnexal mass is detected on CT or MRI in a patient with a primary nonovarian malignancy.

CONCLUSION

Such adnexal masses may be metastases to the ovaries, primary ovarian malignancy, or incidental benign disorders. Solid masses are more likely metastases, but metastases can be predominantly cystic and primary ovarian cancers can be solid. MRI may help characterize incidental benign entities such as endometriosis, fibroma, and peritoneal inclusion cysts.

Prognosis of stage III or IV primary peritoneal serous papillary carcinoma

AIMS

To study the prognosis of patients with stage IIIC/IV primary peritoneal serous papillary carcinoma (PSPC) (study group) compared with that of patients with epithelial ovarian carcinoma (EOC) (control group).

METHODS

A retrospective case-control study including a study group of 37 patients who were matched with a control group of 37 patients. Patients were matched for the histologic subtype (serous tumor), tumor stage, tumor grade, residual disease at the end of debulking surgery (initial or interval) and age (+/-5 years).

RESULTS

Debulking surgery was performed initially or at interval surgery in respectively, 10 and 27 patients in the study group and 17 and 20 in the control group. All patients were treated with platinum-based chemotherapy (combined with paclitaxel in 33) in both groups. The overall survival rate at 3 years in the study and control groups was, respectively, 60% versus 55% (NS). However, event-free survival rates at 3 years (CI 95%) were statistically different (respectively, 29% in the study group versus 16% in the control group: p=0.008).

CONCLUSIONS

Peritoneal disease is more bulky in patients with PSPC. Neoadjuvant chemotherapy is more often required to achieve optimal debulking surgery in PSPC. Overall survival of patients with PSPC is similar to that of their EOC counterparts. Thus, the management of PSPC should not be different from that of advanced stage EOC.

Peritoneal carcinoma in a male patient

Peritoneal carcinoma is a rare primary tumor, described in the literature almost exclusively in women. This report describes our clinicopathological findings in a 51-year-old male patient with peritoneal carcinoma and ascites. Pathologic studies included routine histology, immunohistochemistry and electron microscopy on biopsy and autopsy tumor tissue. After chemotherapy, the patient achieved a complete remission twice, lasting for 14 months and 8 months, respectively, and died after 3 years. His clinical course was similar to that of female patients with peritoneal carcinoma or advanced ovarian cancer. Our case confirms the existence of primary peritoneal carcinoma in males. In addition, it shows that this entity responds to the same chemotherapy as used for ovarian cancer and primary peritoneal carcinoma in females.

Extraovarian peritoneal serous papillary carcinoma: a phase II trial of cisplatin and cyclophosphamide with comparison to a cohort with papillary serous ovarian carcinoma-a Gynecologic Oncology Group Study

OBJECTIVES

The goals of this study were first, to assess the clinical effectiveness of cisplatin and cyclophosphamide in a phase II study involving a well-defined group of women with extraovarian peritoneal serous papillary carcinoma (EPSPC); and second, to compare these results with those of a group of patients with papillary serous ovarian carcinoma (PSOC) who received identical therapy.

METHODS

After primary surgery, patients were treated with cisplatin 75 mg/m(2) and cyclophosphamide 750 mg/m(2) every 21 days for six cycles. Patient demographics, tumor characteristics, clinical and surgical response to treatment, progression-free survival, and overall survival were evaluated. These patients were then compared with patients with PSOC who received identical treatment on a separate protocol.

RESULTS

Women with a diagnosis of tended to be older that those with EPSPC PSOC (median age: 65.8 years vs 60.3 years, P = 0.04). The estimated probability of clinical response (complete and partial) to the treatment regimen for EPSPC was 65% (95% confidence interval [CI]: 41-85%) compared with 59% (95% CI: 47-71%) for women with PSOC. Surgical complete responses were similar (20% vs 19%) in the two patient groups. Additionally, the death rates did not significantly differ between the two groups (hazard ratio: 1.25, 95% CI: 0.834-1.88).

CONCLUSION

Women with EPSPC and PSOC exhibit a similar probability of response to cisplatin and cyclophosphamide and a similar overall survival. Based on these findings and the fact that results of ovarian cancer trials are frequently extrapolated to patients with EPSPC, it is reasonable to include EPSPC patients in future large-scale treatment trials involving patients with advanced ovarian cancer.

Staging ovarian cancer: role of imaging

Ovarian cancer is relatively common, and often presents at an advanced stage with widespread intraperitoneal metastases. The constellation of complex pelvic masses, ascites, omental cake, and other peritoneal implants is virtually diagnostic. All patients are potential surgical candidates, since suspected early stage disease is treated by a comprehensive staging laparotomy including total abdominal hysterectomy, bilateral salpingo-oophorectomy, and omentectomy. Operable advanced disease is treated by surgical debulking and adjuvant combination chemotherapy. The role of imaging is to detect and characterize adnexal masses as likely malignant, recognize unusual findings that may suggest atypical pathology, demonstrate metastases in order to prevent under-staging, and detect specific sites of disease that may be unresectable. These aims are directly related to clinical management; characterization of an adnexal mass as malignant guides appropriate surgical referral, recognition of atypical pathology such as malignant granulosa cell tumor in a young woman may be an indication for fertility-preserving surgery. Demonstration of metastatic site-assists surgical planning, and detection of unresectable disease may be an indication for neoadjuvant (ie, preoperative) chemotherapy with interval debulking rather than primary debulking with adjuvan (postoperative) chemotherapy.

Primary papillary serous carcinoma of the peritoneum in a man

BACKGROUND

Primary papillary serous carcinoma of the peritoneum is a well-known entity in women. The tumour is derived from the extraovarian mesothelium and the pelvis and lower abdomen mesothelia. The treatment strategies are similar to ovarian serous papillary carcinoma.

PATIENTS AND METHODS

A case of primary serous papillary carcinoma of the peritoneum in a man is presented. The patient, 53 years old, died 2 months after diagnosis.

RESULTS

The histologic and immunohistochemical studies of the tumour will be presented. These studies, made during lifetime and at autopsy of the patient, confirm a diagnosis of primary serous papillary carcinoma of the peritoneum.

CONCLUSIONS

primary serous papillary carcinoma of the peritoneum can occur in men, and should be considered in the differential diagnosis in cases of abdominal carcinomatosis of unknown origin. Treatment options remain to be determined.

Tumor suppressor gene, cell surface adhesion molecule, and multidrug resistance in Müllerian serous carcinomas: clinical divergence without immunophenotypic differences

OBJECTIVES

We hypothesize that differences in the expression of selected tumor suppressor genes, cell surface adhesion molecules, and multidrug resistance glycoproteins could account for some of the reported differences between uterine serous carcinoma (USC) and extrauterine serous carcinomas (ESC), including ovarian and primary peritoneal carcinoma (OSC and PSC, respectively).

METHODS

We studied the expression of the following antigens in 20 USCs, 20 OSCs, and 10 PSCs: p53 and mdm-2 (tumor suppressor genes), CD44 and CD44v6 (cell surface adhesion molecules), and the p-glycoprotein (a multidrug resistance protein recognized by two antibodies, C494 and JSB1). We further studied chemotherapeutic drug resistance by examining reports prepared using the Oncotech Extreme Drug Resistance Assay from 24 of the 50 study patients. Clinical data were obtained from medical record review.

RESULTS

USC, OSC, and PSC patients were similar with respect to mean age at diagnosis, mean gravidity, mean parity, personal history of breast cancer, percentage treated with chemotherapy, and survival at 3 and 5 years postdiagnosis. Significant clinical differences included a high prevalence of nulliparity in OSC (P = 0.05), a low prevalence of Caucasian race in USC (P = 0.008), a paucity of stage I patients in OSC and PSC (P = 0.03), a high prevalence of familial breast cancer in OSC (P = 0.06), and superior 2-year survival in OSC (P = 0.02). Seventy-five percent of USCs, 52% of OSCs, and 60% of PSCs expressed p53. Five percent of USCs, 19% of OSCs, and 0% of PSCs expressed mdm-2. Forty percent of USCs, 33% of OSCs, and 10% of PSCs expressed CD44. None of the USCs, OSCs, or PSCs expressed CD44v6. Sixty-one percent of USCs and OSCs and 82% of PSCs expressed C494 while 17% of USCs, 19% of OSCs, and 20% of PSCs expressed JSB1. None of these apparent differences was statistically significant. USC, OSC, and PSCs patients did not demonstrate significant differences with respect to extreme drug resistance. However, the following trends were noted (P = 0.06): more prevalent low drug resistance for cyclophosphamide in OSC compared with USC and more prevalent extreme drug resistance for etoposide in OSC compared with USC.

CONCLUSIONS

Therefore, despite significant clincial differences, the USCs and ESCs in our series do not differ significantly with respect to the expression of the tumor suppressor genes, cell surface adhesion molecules, and drug resistance proteins studied. It is premature, however, to recommend that USCs and ESCs should be treated identically.

Endometrial intraepithelial carcinoma with associated peritoneal carcinomatosis

Endometrial intraepithelial carcinoma (EIC) is a recently described entity, defined as a noninvasive, cytologically malignant lesion that replaces the endometrial surface epithelium. EIC frequently coexists with uterine serous carcinoma (USC) and is hypothesized to be its precursor lesion. However, the clinical significance and biologic potential of finding EIC without USC is not known. We report three postmenopausal women with EIC alone who were found to have multiple, synchronous foci of extrauterine serous carcinoma at presentation. Because the clinical findings in these patients simulated primary peritoneal serous carcinoma (PSC), we compared the clinicopathologic features of these cases with a group of nine bona fide PSCs for which exhaustively sectioned endometria, fallopian tubes, and ovaries were available for review. The average age of the EIC patients was 73 years. Two patients presented with abdominal distention and one with vaginal bleeding. Hysterectomy in each case showed endometrial polyps with EIC, but without invasive USC, in a background of atrophic endometrium. Bilateral salpingo-oophorectomy and staging showed serous carcinoma involving the ovarian hilum, the surfaces of the fallopian tubes and ovaries, in addition to peritoneal carcinomatosis. p53 overexpression was observed in both EIC and the extrauterine deposits of serous carcinoma in each case. The average age of the PSC patients was 66 years. All nine patients presented with abdominal distention. EIC was not identified in any of the hysterectomy specimens. Bilateral salpingo-oophorectomies, omentectomies, and peritoneal biopsies showed peritoneal carcinomatosis, including bulky peritoneal tumor deposits, but only minimal ovarian surface involvement. p53 overexpression was observed in seven cases. These findings indicate that EIC without coincident USC can be associated with invasive, extrauterine serous carcinomatosis. We did not, however, find any significant differences between the clinicopathologic features of primary extrauterine serous carcinomas (PSCs) and those associated with EIC. We conclude that the finding of EIC in an endometrial curettage specimen should prompt a thorough search for an invasive uterine and/or extrauterine serous carcinoma. Conversely, an endometrial origin should be excluded in patients with peritoneal carcinomatosis.

Dermatomyositis and peritoneal papillary serous carcinoma

We describe an unusual case of peritoneal papillary serous carcinoma (PPSC) arising in a female patient with dermatomyositis (DM). Despite periodic extensive searches for an underlying malignancy, no malignancy had been detected in this patient during the first 2.5 years after the diagnosis of DM. It was only when the patient presented with pleural effusion and ascites that the underlying intra-abdominal malignancy was detected by laparoscopy. Treatment with four cycles of pre-operative chemotherapy (taxol and cisplatin) resulted in tumor regression with amelioration in the muscular manifestation of the DM, but without parallelic amelioration in the skin manifestations of the DM. Explorative laparotomy confirmed the presence of papillary serous carcinoma in the omentum, surface of the left ovary and the retroperitoneal lymph nodes, and established the diagnosis of PPSC. Following two cycles of postoperative chemotherapy, the patient is alive with no evidence of internal malignancy. However, although muscle strength and enzymes have remained normal, no effect on the skin manifestation of DM has been observed. This case illustrates that, alongside the more frequently occurring ovarian carcinoma, PPSC should also be considered in the differential diagnosis of the underlying malignancy that may occur in the female patient with DM.