Disseminated peritoneal adenomucinosis and peritoneal mucinous carcinomatosis. A clinicopathologic analysis of 109 cases with emphasis on distinguishing pathologic features, site of origin, prognosis, and relationship to "pseudomyxoma peritonei"

Appendiceal mucinous neoplasms: clinicopathologic study of 116 cases with analysis of factors predicting recurrence

The classification and nomenclature of appendiceal mucinous neoplasms are controversial. To determine the outcome for patients with appendiceal mucinous neoplasms and further evaluate whether they can be stratified into groups that provide prognostic information, the clinicopathologic features of 116 patients (66 with clinical follow-up) with appendiceal mucinous neoplasms were studied. From a wide variety of histopathologic features assessed, the important predictors that emerged on univariate statistical analysis were presence of extra-appendiceal neoplastic epithelium (P=0.01), high-grade cytology (P<0.0001), architectural complexity (P<0.001), and invasion (P<0.001). Stratification using a combination of these predictors resulted in a 4-tiered classification scheme. All 16 patients with mucinous neoplasms confined to the appendix and lacking high-grade cytology, architectural complexity, and invasion were alive with no recurrences at median 59 months follow-up (=mucinous adenoma). One of 14 patients with low-grade cytology and acellular peritoneal mucin deposits developed recurrent tumor within the peritoneum at 45 months with no patient deaths to date (median, 48-mo follow-up) (=low-grade mucinous neoplasm with low risk of recurrence). None of the 2 patients with acellular peritoneal mucinous deposits outside of the right lower quadrant developed recurrence at 163 and 206 months. Twenty-seven patients with low-grade mucinous neoplasms with extra-appendiceal neoplastic epithelium had 1-year, 3-year, 5-year, and 10-year overall survival rates of 96%, 91%, 79%, and 46%, respectively, at median 53 months follow-up (=low-grade mucinous neoplasm with high risk of recurrence). Three of the 4 patients with extra-appendiceal epithelium limited to the right lower quadrant developed full-blown peritoneal disease at 6, 41, and 99 months follow-up and 1 patient eventually died of disease. Nine patients with appendiceal neoplasms with invasion or high-grade cytology and follow-up showed 1-year, 3-year, and 5-year overall survival rates of 86%, 57%, and 28% (=mucinous adenocarcinoma). At 10 years, all patients with mucinous adenocarcinoma were either dead or lost to follow-up. Appendiceal mucinous neoplasms can be stratified into 4 distinct risk groups on the basis of a careful histopathologic assessment of cytoarchitectural features and extent of disease at presentation.

Pseudomyxoma peritonei

Pseudomyxoma peritonei (PMP) is an uncommon “borderline malignancy” generally arising from a perforated appendiceal epithelial tumour. Optimal treatment involves a combination of cytoreductive surgery (CRS) with heated intraperitoneal chemotherapy (HIPEC). Controversy persists regarding the pathological classification and its prognostic value. Computed tomography scanning is the optimal preoperative staging technique. Tumour marker elevations correlate with worse prognosis and increased recurrence rates. Following CRS with HIPEC, 5-year survival ranges from 62.5% to 100% for low grade, and 0%-65% for high grade disease. Treatment related morbidity and mortality ranges from 12 to 67.6%, and 0 to 9%, respectively. Surgery and HIPEC are the optimal treatment for PMP which is at best a “borderline” peritoneal malignancy.

Intraperitoneal hyperthermic chemotherapy: an evolving paradigm for the treatment of peritoneal surface malignancies

Unfortunately, advanced colorectal cancer is often present at the time the disease is diagnosed. Many intra-abdominal malignancies spread throughout the peritoneal cavity, which is known as carcinomatosis. Peritoneal carcinomatosis is uniformly a terminal disease with a median survival of 6 months. Systemic chemotherapy is palliative and generally provides limited improvement in survival. Conventional surgery has typically been limited to ileostomy, colostomy or intestinal bypass procedures. Cytoreductive surgery alone has long been used to treat macroscopic disease, with limited success. However, cytoreductive surgery combined with intraperitoneal hyperthermic chemotherapy (IPHC) has evolved into a novel approach for peritoneal surface malignancy. IPHC was initially described in a canine model by Spratt. Although the first clinical series of peritoneal perfusion were small, Japanese trials, which utilized IPHC for prophylaxis in patients with gastric adenocarcinoma, Fujimoto was the first to report an improvement in survival for established gastric cracinomatosis. This early work provided the proof-of-principle for what has evolved into current management with aggressive cytoreduction and IPHC. The present review will outline the rationale, current practice and future directions of IPHC in the management of peritoneal surface malignancies.

Clinicopathological analysis of primary epithelial appendiceal neoplasms

Appendiceal carcinomas are classified into three distinct histopathological disease entities: disseminated peritoneal adenomucinosis (DPAM), peritoneal mucinous carcinomatosis (PMCA), or peritoneal mucinous carcinomatosis with intermediate or discorant features (PMCA I/D). The treatment of appendiceal tumors should be based on accurate histopathological classification, per previously reported case series. The objective of this study was to evaluate the clinicopathologic presentation and outcome of patients with appendiceal tumors treated at our institution over a 15-year period. We identified patients with appendiceal tumors diagnosed or treated at our institution from January 1989 through May 2004. Chart review for age, gender, signs and symptoms at diagnosis, and treatment was performed. Review of the pathologic specimens was performed and tumors were classified as DPAM, PMCA I/D, or PMCA. Forty patients were identified (median age 52.5 years; males 38%). The number of patients with DPAM, PMCA I/D, and PMCA was 15 (38%), 6 (15%), and 18 (46%), respectively. Peritoneal involvement was seen in 11 (73%) of patients with DPAM, 5 (83%) of PMCA I/D, and 11 (61%) of PMCA. The median survival for patients with DPAM, PMCA I/D, and PMCA was 7.7 years (90% CI: 2.9--upper limit not estimable), 1.2 years (90% CI: 0.9-1.6), and 0.7 years (90% CI: 0.4-1.5), respectively. The difference in survival across the three groups was statistically significant. Three distinct histopathological disease entities exist in appendiceal tumors. The prognosis and management of these tumors should be based on the extent of disease and pathologic diagnosis.

Pseudomyxoma peritonei: role of 18F-FDG PET in preoperative evaluation of pathological grade and potential for complete cytoreduction

INTRODUCTION

For pseudomyxoma peritonei (PMP), survival depends on pathological grade and completeness of cytoreductive surgery. The aim of the study was to assess the ability of preoperative 18F-FDG PET to determine these 2 prognosis indicators.

MATERIAL AND METHODS

In this prospective single centre study, all patients presenting with PMP were included. They underwent a preoperative 18F-FDG PET with a double radiological evaluation and an explorative laparotomy with the objective of optimal cytoreduction followed by a hyperthermic intra-operative intraperitoneal chemotherapy (HIPEC). Patients with non resectable disease underwent debulking surgery without HIPEC. The Completeness of Cytoreduction was assessed by CC score.

RESULTS

Thirty-four patients were included. PET scanning was positive for 19 patients with grade II (hybrid form) or III (Peritoneal Mucinous Carcinomatosis) and for 2 patients with grade I (disseminated peritoneal adenomucinosis), and negative for 3 patients with grade II - III and for 10 patients with grade I. PET scanning was positive for 6 patients with CC score 2 - 3 and for 16 patients with CC score 0, and negative for 2 patients with CC score 2 - 3 and for 10 patients with CC score 0. The 18F-FDG PET interpretation distinguished 2 patients groups (grade I and grade II - III) with a sensitivity of 90% and a specificity of 77%. Moreover, probability of complete cytoreduction when PET was negative was over 80%.

CONCLUSION

Preoperative 18F-FDG PET may predict pathological grade and completeness of cytoreduction which are the two main prognostic factors in patients with PMP.

Critical analysis of 33 patients with peritoneal carcinomatosis secondary to colorectal and appendiceal signet ring cell carcinoma

BACKGROUND

Primary signet-ring cell carcinoma (SRC) of colorectal and appendiceal origin is a rare entity with an aggressive biology and clinical behavior. The majority of patients develop peritoneal carcinomatosis (PC) early in the disease. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) may potentially improve survival.

METHODS

An observational study of 33 patients with SRC of colorectal or appendiceal origin was identified through a retrospective review of two peritoneal surface malignancy databases between January 1997 and December 2008. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

Thirty-three patients (18 women (55%); mean age at diagnosis of carcinomatosis, 49 (standard deviation = 12) years) were identified to have SRC, with 15 cases of colorectal and 18 of appendiceal origin. For patients with colonic SRC who underwent complete CRS and HIPEC versus systemic chemotherapy only, the median survival was 13 and 18 months (P = 0.75). For patients with appendiceal SRC who underwent complete CRS and HIPEC versus systemic chemotherapy only, the median survival was 27 and 15 months (P = 0.12).

CONCLUSIONS

There seems to be less survival benefits after a complete CRS and HIPEC as a curative treatment for PC from colorectal SRC compared with that for non-SRC colorectal adenocarcinoma. However, in patients with appendiceal SRC, long-term survival is a reality after treatment.

[Appendiceal mucoceles, pseudomyxoma peritonei and appendiceal mucinous neoplasms: update on the contribution of imaging to choice of surgical approach]

INTRODUCTION

The treatment of pseudomyxoma peritonei (PMPs) and appendiceal mucocele (AM) has changed radically. To assess the contribution of preoperative imaging to the treatment strategy and choice of approach, a surgeon and a radiologist different from the initial radiologist examined the files of all patients treated for PMP or AM in four facilities in one district from January 1, 1996, through December 31, 2008.

PATIENTS AND METHODS

The study included 27 patients (20 men and seven women, mean age: 63+/-13 years). Eleven patients had an intact AM, seven synchronous PMP (malignant appendiceal lesion in two of seven), six metachronous PMP (five with peritoneal mucinous carcinomatosis and one with diffuse peritoneal adenomucinosis) and three a ruptured AM but not PMP. The incidence of mucin-secreting tumors observed (27 cases in 12 years in a region of 500 000 inhabitants) corresponds to a prevalence of approximately five cases per year per million inhabitants. Acute clinical pictures (7/27) were significantly more frequent for the malignant forms (5/7) (p<0,02).

RESULTS AND DISCUSSION

The overall sensitivity of computed tomography (CT) for all the criteria studied was 93%. The predictive value for AM rupture of visualization of thick calcifications was 100%. On the other hand, rupture never occurred when the CT showed an AM under pressure, with thin walls and septa. The predictive value for PMP of "scalloping" was 100%. The diagnostic accuracy of the initial reading was 25/27 for the imaging overall and 25/25 for the CT. Preoperative visualization of the exact size of the intact AM or of diagnostic information about ruptured AM and PMP helped to select an appropriate approach in 25 of 27 cases.

[Endometrial and endocervical lesions associated with pseudomyxoma peritonei: a case report]

The association of a pseudomyxoma peritonei with a mucinous tumor of the appendix and/or the ovary is regularly reported in the literature. However, in this context, endometrial or endocervical lesions remain exceptional. We report the case of a 57-year-old patient, with pseudomyxoma peritonei associated with a low-grade mucinous neoplasia of appendix and both ovaries. The systematic sampling of endometrium and endocervix showed small segments of intestinal epithelium admixed with native epithelium. Histological and immunohistochemical characteristics of this epithelium were quite comparable to those observed in the appendix and ovaries. The endocervical and endometrial lesions might represent an implantation of mucinous epithelium from appendix, emphasizing the capacity of this epithelium to implant at a distance from the original lesion.

Secondary tumors and tumorlike lesions of the peritoneal cavity: imaging features with pathologic correlation

Tumors and tumorlike lesions that secondarily involve the mesothelial or submesothelial layers of the peritoneum are a diverse group of disorders that range in biologic behavior from benign to highly malignant. The anatomy of peritoneal ligaments and mesenteries and the normal circulation of peritoneal fluid dictate location and distribution of these diseases within the peritoneal cavity. Peritoneal carcinomatosis is the most common secondary tumor to affect the peritoneal cavity. When it arises from carcinomas of the gastrointestinal tract or ovary, the prognosis is grave. However, when low-grade mucinous adenocarcinoma of the appendix spreads to the peritoneal cavity, the consequence is typically pseudomyxoma peritonei, which is a clinical syndrome, characterized by recurrent and recalcitrant voluminous mucinous ascites due to surface growth on the peritoneum without significant invasion of underlying tissues. Carcinomas from elsewhere in the body, as well as lymphomas and sarcomas, may also produce diffuse peritoneal metastasis. Granulomatous peritonitis is the consequence of disseminated infection such as tuberculosis or histoplasmosis, foreign materials, or rupture of a tumor or hollow viscus. Finally, a group of benign miscellaneous conditions that range from common disorders such as endometriosis and splenosis to very rare conditions such as gliomatosis peritonei and melanosis may also affect the peritoneum diffusely. Secondary tumors and tumorlike lesions of the peritoneum have overlapping imaging features when compared with each other and primary peritoneal tumors. Knowledge of peritoneal anatomy, normal fluid circulation within the peritoneal cavity, and clinical and pathologic features of secondary peritoneal lesions is essential for identification of these lesions.

Management of appendiceal pseudomyxoma peritonei diagnosed during pregnancy

BACKGROUND

The incidence of cancer during pregnancy is approximately 1 in 1000. The most common types encountered during pregnancy are cervical, breast and ovarian. Epithelial tumors of the appendix on the other hand are rare and account for only approximately 1% of all colorectal neoplasms; the occurrence of this neoplasm during pregnancy is extremely rare.

CASE PRESENTATION

The medical history of a 30 year old woman diagnosed at 17 weeks gestation with an appendiceal mucinous tumor with large volume pseudomyxoma peritonei was presented. Her pregnancy was preserved and she had an early vaginal delivery of a healthy baby at 35 weeks. At 2 1/2 weeks postpartum the patient underwent extensive cytoreductive surgery and intraperitoneal chemotherapy. She remains disease-free 5 years after her initial diagnosis. A literature review of this clinical situation and a discussion of treatment plans were presented.

CONCLUSION

The management of an appendiceal tumor with pseudomyxoma peritonei diagnosed during pregnancy requires full knowledge of the natural history of this disease to achieve a balance of concern for maternal survival and fetal health.

Phase II study of regional treatment for peritoneal carcinomatosis

BACKGROUND

Cytoreductive surgery with hyperthermic intraperitoneal chemotherapy and early postoperative intraperitoneal chemotherapy is becoming an accepted treatment of carcinomatosis.

METHODS

Between February 2000 and January 2008, there were 101 consecutive patients with carcinomatosis who were treated with cytoreductive surgery + hyperthermic intraperitoneal chemotherapy and early postoperative intraperitoneal chemotherapy. Patient and tumor characteristics, surgical details, complications, disease-free survival (DFS), and overall survival (OS) were recorded prospectively.

RESULTS

The majority (82%) of patients, median age 49 years (range, 18-77 y), had complete macroscopic cytoreduction (completeness of cytoreduction score, 0) despite a generally extensive tumor burden. Perioperative mortality and grade III/IV morbidity rates were 4% and 39%, respectively. Preliminary median DFS and OS have not been defined for appendix tumors at a median follow-up period of 16 months (range, 1-86 mo). Median DFS and OS for colonic tumors are 8 months and 26 months, respectively, with a median follow-up period of 12 months (range, 1-48 mo).

CONCLUSIONS

Combined regional treatment is feasible and holds significant promise for the treatment of peritoneal carcinomatosis.

Long-term survival in patients with pseudomyxoma peritonei treated with cytoreductive surgery and perioperative intraperitoneal chemotherapy: 10 years of experience from a single institution

BACKGROUND

Cytoreductive surgery (CRS) and perioperative intraperitoneal chemotherapy (PIC) has been recognized as a treatment option for pseudomyxoma peritonei. This study reports the survival outcomes, clinicopathological prognostic factors, and a learning curve from a single institution's experience.

METHODS

Patients with pseudomyxoma peritonei underwent CRS and PIC, which was comprised of hyperthermic intraperitoneal chemotherapy (HIPEC) and/or early postoperative intraperitoneal chemotherapy (EPIC), according to a standardized treatment protocol in our institution. Clinicopathological factors were analyzed to determine their prognostic value for survival using univariate and multivariate analysis. Time period comparison was performed to study the effect of a learning curve.

RESULTS

A total of 106 patients (43 men and 63 women) were treated. The mortality rate was 3% and severe morbidity rate was 49%. The median follow-up was 23 (range, 0-140) months. The overall median survival was 104 months with a 5-year survival rate of 75%. The progression-free survival was 40 months with a 1-year progression-free survival rate of 71%. Factors influencing survival include histopathological type of tumor, use of both HIPEC and EPIC, peritoneal cancer index, completeness of cytoreduction, and severe morbidity. The results demonstrate a learning curve where patients with a higher peritoneal cancer index (PCI) were treated, reduced amount of blood products required, more patients undergoing HIPEC and the combined HIPEC and EPIC, more redo-procedures performed, and a longer progression-free survival.

CONCLUSIONS

This report demonstrates long-term survival outcomes, acceptable perioperative outcomes, and a learning curve associated with the treatment of patients with pseudomyxoma peritonei.

Adenocarcinoma of the appendix is rarely detected by colonoscopy

INTRODUCTION

Appendiceal tumors represent a subset of colonic neoplasms that frequently defy early diagnosis only to present at advanced stage with peritoneal metastasis. Data on early detection by colonoscopy is limited to case reports or series. The aim of this study is to determine the diagnostic yield of colonoscopy in detecting appendiceal lesions in patients with appendiceal adenocarcinoma and pseudomyxoma peritonei.

METHODS

We reviewed clinicopathologic data on 121 consecutive patients with histologically confirmed appendiceal adenocarcinoma with pseudomyxoma peritonei presenting to our institution for intraperitoneal hyperthermic chemotherapy (IPHC) and cytoreductive surgery between February, 1993 and August, 2007, focusing on the colonoscopy findings.

RESULTS

Preoperative colonoscopic data were available on 64 patients (average age = 51; 52 for IPHC patients). Abnormal findings included seven patients with appendiceal lesions (11%), 12 patients with cecal abnormalities (19%), and 28 patients with polyps (44%). Twenty-three patients (36%) had a normal colonoscopy. Malignancy was documented in two of the 64 (3.1%) patients on preoperative colonoscopy biopsies.

CONCLUSIONS

Appendiceal abnormalities are infrequently seen on colonoscopy and rarely yield a diagnostic biopsy in patients with appendiceal carcinoma. We found that nearly 42% of patients with carcinoma of the appendix have synchronous colonic polyps, a much higher prevalence than would be expected, supporting a role for a perioperative colonoscopy.

Thoracic cytoreductive surgery and intraoperative hyperthermic intrathoracic chemotherapy for pseudomyxoma peritonei

BACKGROUND

Pleural dissemination of pseudomyxoma peritonei (PMP) is considered an advanced/terminal disease. We review our experience with thoracic cytoreductive surgery (CRS) and intraoperative hyperthermic intrathoracic chemotherapy (HITHOC) for the treatment of pleural recurrence of PMP following previous intraabdominal surgery.

PATIENTS AND METHODS

An observational study of five patients with pleural dissemination from PMP treated with thoracic CRS and intraoperative HITHOC with mitomycin C for 90 min at 41.5 degrees C.

RESULTS

There were three men. The mean age was 46.5 (10.5) years. Postoperatively, one patient developed Grade I, one patient developed Grade III and one patient developed Grade IV postoperative complication. Two patients had an unremarkable postoperative recovery. Only one patient has died 38 months since treatment from abdominal complication of this disease with no evidence of thoracic disease. The four surviving patients are still alive 4.6-47.4 months after treatment. Two patients have evidence of an intraabdominal recurrence.

CONCLUSIONS

Thoracic CRS and intraoperative HITHOC is a safe and effective procedure to treat pleural dissemination from PMP. Long-term disease-free survival can be achieved from this treatment for which no other potentially curative therapy has been described.

Pseudomyxoma peritonei: biological features are the dominant prognostic determinants after complete cytoreduction and hyperthermic intraperitoneal chemotherapy

OBJECTIVE

To investigate outcome and prognostic factors in patients with pesudomyxoma peritonei (PMP) treated by complete cytoreduction and hyperthermic intraperitoneal chemotherapy.

BACKGROUND

After comprehensive treatment, prognosis of PMP is predominantly dependent on the completeness of cytoreduction. Once complete cytoreduction is achieved, additional factors predicting long-term outcome are still poorly understood.

METHODS

From a prospective database, we selected 102 patients undergoing complete cytoreduction (residual tumor nodules < or =2.5 mm) and closed-abdomen hyperthermic intraperitoneal chemotherapy with mitomycin-C and cisplatin. Previously, 22 patients had systemic chemotherapy. PMP was histologically classified into disseminated peritoneal adenomucinosis, peritoneal mucinous carcinomatosis (PMCA), and intermediate/discordant group. Twenty-one patient-, tumor-, and treatment-related variables were assessed by multivariate analysis with respect to overall (OS) and progression-free (PFS) survival. The following immunohistochemical markers were tested: cytokeratin (CK)-7, CK-20, CDX-2, MUC-2, and MUC-5AC.

RESULTS

Operative mortality was 1%. Seventy-eight patients were diagnosed with disseminated peritoneal adenomucinosis, 24 with PMCA, none with intermediate/discordant group. For the overall series, median follow-up, 5-year OS, and PFS were 45 months (range 1-110), 84.4%, and 48.3%, respectively. In most cases, CK20, CDX-2, and MUC-2 were diffusely positive, whereas CK-7 and MUC-5AC were variably expressed. At multivariate analysis, previous systemic chemotherapy and PMCA correlated to both worse OS and PFS, elevated serum CA125 only to worse PFS. CK20, CDX-2, and MUC-2 expression correlated to prognosis at univariate analysis.

CONCLUSIONS

After complete cytoreduction and hyperthermic intraperitoneal chemotherapy, prognosis of PMP is primarily dependent on pathologic and biologic features. MUC-2, CK-20, and CDX-2 may be related to the disease biology. Understanding PMP molecular basis may facilitate personalized treatment.

Interstitial pneumonitis following intrapleural chemotherapy

Background

Mucinous neoplasms within the abdomen may disseminate by direct extension through the diaphragm to involve the pleural space. Treatment of this condition is by parietal and visceral pleurectomy followed by hyperthermic intrapleural chemotherapy.

Case presentation

In this case report a patient developed persistent right upper lobe interstitial pneumonitis and progressive parenchymal fibrosis following intrapleural chemotherapy treatment with mitomycin C and doxrubicin. The condition persisted until death 28 months later. Death was from progressive intraabdominal disease with intestinal obstruction and sepsis associated with progressive pulmonary parenchymal disease. The right pleural space disease did not recur.

Conclusion

This manuscript is the first case report describing interstitial pneumonitis and lung fibrosis following intrapleural chemotherapy. Since pulmonary toxicity from chemotherapy is a dose-dependent phenomenon, dose reduction of intrapleural as compared to intraperitoneal hyperthermic chemotherapy may be necessary.

Low grade peritoneal mucinous carcinomatosis associated with human papilloma virus infection: case report

Pseudomyxoma peritonei is a clinical syndrome characterized by peritoneal dissemination of a mucinous tumor with mucinous ascites. The vast majority of the pseudomyxoma peritonei are associated with mucinous neoplasms of the appendix. We describe a case of pseudomyxoma peritonei associated with mucinous adenocarcinoma of the cervix in a 60-year-old woman. The patient developed low grade mucinous peritoneal carcinomatosis 8 years after hysterectomy for cervical adenocarcinoma. No other primary mucinous tumor was identified and peritoneal carcinomatosis tested positive for high-risk human papilloma virus (HPV), showing both integrated and episomal pattern. HPV has been previously associated with development of cervical carcinomas (both squamous and mucinous) but neither has cervical adenocarcinoma nor HPV been implicated in development of pseudomyxoma peritonei. To the best of our knowledge, this is the first description of HPV-associated malignancy presenting as pseudomyxoma peritonei.

Metastatic appendiceal mucinous adenocarcinoma to well-differentiated diffuse mesothelioma of the peritoneal cavity: a mimicker of florid mesothelial hyperplasia in association with neoplasms

Atypical/florid mesothelial hyperplasia associated with another neoplastic process is not an infrequent phenomenon and has been reported in a variety of tumors. In those instances, the mesothelial proliferation might create a misdiagnosis of metastatic carcinoma but seldom raises the possibility of a well-differentiated mesothelioma seeded by metastatic neoplastic cells. Herein, we report the case of a 40-year-old woman originally diagnosed with exuberant atypical mesothelial hyperplasia after an diagnostic laparoscopy. The subsequent operation, however, demonstrated a mucinous neoplasm of the appendix with involvement of the peritoneal cavity in the form of peritoneal mucinous carcinomatosis as well as metastases to the uterine serosa and adnexal surfaces. Microscopic analysis revealed an appendiceal adenocarcinoma with signet-ring-cell features that has metastasized to a diffuse well-differentiated mesothelioma of the peritoneal cavity. In many areas, the atypical mesothelial proliferation is indistinguishable from florid mesothelial hyperplasia. The true nature of the mesothelial proliferation was only confirmed after extensive additional sampling, which showed unequivocal stromal invasion. To the best of our knowledge, this is the first report of a metastatic appendiceal mucinous adenocarcinoma to a well-differentiated diffuse mesothelioma of the peritoneal cavity. Although commonly associated with atypical/ florid mesothelial hyperplasia, a carcinoma can rarely metastasize to a well-differentiated mesothelioma, which can pose significant diagnostic difficulties because it can mimic a reactive process. This unusual case report expands the spectrum of mesothelial proliferation in conjunction with a malignant neoplasm and serves to remind pathologists that such a concomitant occurrence exists.

Cytoreduction and hyperthermic intraperitoneal chemotherapy in the treatment of peritoneal carcinomatosis from pseudomyxoma peritonei

AIM: To investigate the most important aspects of hyperthermic intraperitoneal chemotherapy (HIPEC) that has been accepted as the standard treatment for pseudomyxoma peritonei (PMP), with special regard to morbidity, overall survival (OS) and disease free survival (DFS) over 10 years.

METHODS: Fifty-three patients affected by PMP underwent cytoreduction (CCR) and HIPEC with a “semi-closed” abdomen technique in our institution. The peritonectomy procedure and completeness of CCR were classified according to Sugarbaker criteria. Preoperative evaluation always included thoracic and abdominal CT scan to stage peritoneal disease and exclude distant metastases. Fifty-one patients in our series were treated with a protocol based on administration of cisplatinum 100 mg/m² plus mitomycin C 16 mg/m², at a temperature of 41.5°C for 60 min. Anastomoses were always performed at the end of HIPEC. The mean duration of surgery was 12 h including HIPEC. Continuous monitoring of hepatic and renal functions and hydroelectrolytic balance was performed in the postoperative period.

RESULTS: Twenty-four patients presented with postoperative complications: surgical morbidity was observed in 16 patients and 6 patients were re-operated. All complications were successfully treated and no postoperative deaths were observed. Risk factors for postoperative morbidity were considered to be gender, age, body surface, duration of surgery, Peritoneal Cancer Index (PCI) and tumor residual value (CC score). No statistically significant correlation was found during the multivariate analysis: only the CC score was statistically significant. The OS in our experience was 81.8%, with a DFS of 80% at 5 years and of 70% at 10 years.

CONCLUSION: In our experience, even if HIPEC combined with cytoreductive surgery involves a high risk of morbidity, postoperative complications can be resolved favorably in most cases with correct patient selection and adequate postoperative care, thus minimizing mortality. The association of CCR and HIPEC can be considered as the standard treatment for PMP. The OS and DFS results confirm the validity of this combined approach for the treatment of this rare neoplasm. The impact of preoperative chemotherapy on OS, in our opinion, is due to a major aggressiveness of tumors in treated patients.

Experience with adjuvant chemotherapy for pseudomyxoma peritonei secondary to mucinous adenocarcinoma of the appendix with oxaliplatin/fluorouracil/leucovorin (FOLFOX4)

Background

Pseudomyxoma peritonei (PMP) is a rare condition characterized by mucinous tumors, disseminated intra-peritoneal implants, and mucinous ascites. So far its diagnosis remains challenging to most clinicians.

Case presentation

A 55-year-old male patient had suffered from acute onset of abdominal pain and abdominal distension for one day prior to his admission. Physical examination revealed tenderness over the right lower quadrant of the abdomen without diffuse muscle guarding. A large amount of ascites was identified by abdominal computed tomography (CT) scan. Paracentesis showed the appearance of sticky mucinous ascites. He underwent laparotomy under the impression of pseudomyxoma peritonei. There was a lot of mucinous ascites, one appendiceal tumor and multiple peritoneal implants disseminated from the subphrenic space to the recto-vesicle pouch. Pseudomyxoma Peritonei caused by mucinous adenocarcinoma of appendiceal origin, was confirmed by histopathology. We performed an excision of the appendiceal tumor combined with copious irrigation and debridement. After the operation, he received 10 cycles of systemic chemotherapy with FOLFOX4 regimen, without specific morbidity. Follow-up of abdominal CT and colonoscopy at post-operative 17 months showed excellent response without evidence of local recurrence or distal metastasis. He made an uneventful recovery (up to the present) for 21 months after the operation.

Conclusion

This case report emphasizes the possible new role of systemic chemotherapy in the treatment of patients with this rare clinical syndrome.

Appendiceal carcinoma: a diagnostic and therapeutic challenge

Appendiceal carcinoma is a very rare clinical entity, constituting 1% of all colorectal malignancies and 1% of all appendectomy specimens. Appendiceal malignancies often present atypically, thus creating diagnostic challenges. We present a patient with mucinous carcinoma of the appendix who presented with hematuria and abdominal pain. Similar case reports are extremely rare in the literature, while typical presentations of appendiceal carcinoma include abdominal pain, abdominal mass, early satiety, nausea, and iron-deficiency anemia. Initially, the diagnostic investigation in our patient was focused on urinary tract disorders, but ultimately resulted in finding a mucinous appendiceal carcinoma. The carcinoma had invaded the urinary bladder and was disseminated in the peritoneal cavity. Aggressive cytoreductive surgery is the most common therapeutic approach for disseminated tumors, often followed by intraperitoneal chemotherapy. However, treatment should be individualized based on patient-specific parameters, such as the presence of comorbidities, performance status, as well as the presence of metastatic disease. Our patient had optimal cytoreduction with subsequent systemic therapy with 5-fluorouracil, leucovorin, oxaliplatin, and bevacizumab, a monoclonal antibody directed against vascular endothelial growth factor. She completed her treatment regimen without complications and is currently being restaged. An integrative approach is required in the diagnostic investigation and management of appendiceal malignancies.

Consensus statement on the loco-regional treatment of appendiceal mucinous neoplasms with peritoneal dissemination (pseudomyxoma peritonei)

Pseudomyxoma peritonei (PMP) is a rare condition mostly originating from low malignant potential mucinous tumours of the appendix. Although this disease process is minimally invasive and rarely causes haematogenous or lymphatic metastases, expectation of long-term survival are limited with no prospect of cure. Recently, the combined approach of cytoreductive surgery (CRS) and perioperative loco-regional chemotherapy (PLC) has been proposed as the standard of treatment for the disease. The present paper summarizes the available literature data and the main features of the comprehensive loco-regional treatment of PMP. The controversial issues concerning the indications and technical methodology in PMP management were discussed through a web-based voting system by internationally known experts. Results were presented for further evaluation during a dedicated session of "The Fifth International Workshop on Peritoneal Surface Malignancy (Milan, Italy, December 4-6, 2006)". The experts agreed that multiple prospective trials support a benefit of the procedure in terms of improved survival, as compared with historical controls. Concerning the main controversial methodological questions, there was an high grade of consistency among the experts and agreement with the findings of the literature.

Primary signet ring cell carcinoma of the appendix: A rare case report and our 18-year experience

Primary adenocarcinoma of the appendix is a rare malignancy that constitutes < 0.5% of all gastrointestinal neoplasms. Moreover, primary signet ring cell carcinoma of the appendix is an exceedingly rare entity. We have encountered 15 cases of primary appendiceal cancer among 3389 patients who underwent appendectomy over the past 18 years. In the present report, we describe a rare case of primary signet ring cell carcinoma of the appendix with ovarian metastases and unresectable peritoneal dissemination occurring in a 67-year-old female patient. She underwent appendectomy and bilateral salpingo-oophorectomy with a laparoscopy procedure. She then received palliative systemic chemotherapy with 12 cycles of oxaliplatin, 5-fluorouracil, and leucovorin (FOLFOX-4). The patient currently is well without progression of disease 12 mo after beginning chemotherapy.

Peritoneal pseudomyxoma: results of a systematic policy of complete cytoreductive surgery and hyperthermic intraperitoneal chemotherapy

BACKGROUND

Pseudomyxoma peritonei (PMP) is characterized by progressive intraperitoneal accumulation of mucous and mucinous implants, usually derived from a ruptured, possibly malignant mucinous neoplasm of the appendix. Treatment based on complete cytoreductive surgery (CCRS) with hyperthermic intraperitoneal chemotherapy (HIPEC) is gaining support. The aim of this study was to identify pre- and perioperative factors of prognostic value.

METHODS

A total of 105 patients (with no residual tumours exceeding 2 mm) were treated with CCRS plus HIPEC based on oxaliplatin. Clinical, radiological, pathological factors and blood markers were analysed to determine their prognostic value for survival.

RESULTS

Mortality (7.6 per cent) and morbidity (67.6 per cent) were significantly correlated with peritoneal index, pathological grade and blood CA19.9 level. The median follow-up was 48 months. Seven patients died after hospital discharge. Overall and disease-free 5-year survival rates were 80.0 and 68.5 per cent respectively. The Cox model identified only two significant factors impacting on disease-free survival: CA19.9 level and pathological grade.

CONCLUSION

CCRS is the most effective treatment for PMP, and adding HIPEC prolongs long-term survival. Further strategies should focus on improving postoperative outcome in extended PMP.

Retrospective multicenter study of a clinicopathologic analysis of pseudomyxoma peritonei associated with ovarian tumors (KGOG 3005)

The purpose of this study is to assess clinicopathologic features of pseudomyxoma peritonei (PMP) that has ovarian pathology and its relationship with the prognosis. From 1995 to 2004, the clinical records and follow-up data of 35 patients with PMP, which had primarily originated from the ovary, were collected from 11 institutes of gynecologic oncology in Korea and retrospectively analyzed. All patients had ovarian lesion histologically confirmed with PMP. The mean age at diagnosis was 53.7 years (range: 16-82 years). There were 25 (71.4%) patients with disseminated peritoneal adenomucinosis, 5 (14.3%) with peritoneal mucinous carcinomatosis with intermediate group, and 5 (14.3%) with peritoneal mucinous carcinomatosis. The clinical stages at diagnosis were IA in 2 patients, IIIB in 4, IIIC in 23, IV in 1, and unknown in 5. In preoperative tumor markers, the positive rates were 72% (CA125), 47.4% (CA19-9), and 84.6% (CEA). Thirty-four patients underwent surgical staging or cytoreduction, and then 27 patients (77%) received adjuvant chemotherapy that was given to patients in a nonuniform fashion. The 5-year survival for 35 patients was 87%. Survival rate was significantly lower in patients >50 years of age (P = 0.002). Our data showed that age of the patient is the only significant prognostic factor in PMP that has ovarian lesion.

Carcinoma of extrahepatic bile ducts and gallbladder metastatic to the ovary: a report of 16 cases

Information on ovarian metastasis of carcinoma of the extrahepatic bile ducts and gallbladder is limited. Sixteen examples are reported; 3 primary tumors were hilar cholangiocarcinomas, 5 common bile duct carcinomas, and 8 gallbladder carcinomas. The patients ranged from 21 to 87 years (mean, 59 years); 7 presented to gynecologists with nonspecific pelvic symptoms similar to primary ovarian neoplasms. The primary tumor was identified before the detection of the ovarian lesions in 5 cases, was simultaneously detected with the ovarian metastases in 9, and was diagnosed postoperatively in 2. All but one case had bilateral ovarian involvement. The thirty-one ovarian lesions included twenty-nine grossly abnormal ovaries that were enlarged (range, 3.0-16.5 cm, mean, 9.4 cm) and 2 ovaries with only microscopic involvement. The sectioned surface was solid in 9, solid-cystic in 15, and multicystic in 5. Microscopically, ovarian surface implants were seen in 66%, multinodular growth in 58%, and infiltrative stromal invasion in 81%. Mucinous epithelial differentiation was seen in 81%, sometimes with foci of benign-like or borderline-like epithelium simulating primary ovarian mucinous neoplasia. Cystadenoma and cystadenofibroma of nonmucinous type was even mimicked strikingly in some cases because of flattening of epithelium lining glands and cysts. Signet ring cells were present in sufficient quantity for a diagnosis of Krukenberg tumor in four tumors. Colloid-type carcinoma was observed at least focally in 3 tumors. Nonmucinous carcinomatous components included adenocarcinoma with high-grade endometrioid-like morphology in 2 cases, papillary adenocarcinoma simulating mixed müllerian epithelial adenocarcinoma in 1, and undifferentiated carcinoma in 2. Immunohistochemical studies in 8 cases showed a positive reaction for cytokeratin 7 in all and for cytokeratin 20 in 4 cases. The high rate of bilaterality, surface involvement, multinodular growth, and heterogeneity of patterns were the most helpful features for indicating a metastatic nature, with signet ring cells also being helpful in the minority of cases in which they were present. Although the diagnosis of a metastatic tumor to the ovary is possible in most of the cases based on standard diagnostic criteria, problems in the differential diagnosis may be posed by morphologic patterns that overlap strikingly with primary ovarian neoplasms, benign, borderline, and malignant, as discussed herein.

A pharmacologic analysis of intraoperative intracavitary cancer chemotherapy with doxorubicin

PURPOSE

A pharmacologic analysis of intracavitary doxorubicin in the treatment of patients with intracavitary cancer dissemination was performed to further evaluate the possible benefits of this treatment modality.

METHODS

Twenty appendiceal malignancy patients with peritoneal carcinomatosis (PC), three appendiceal malignancy patients with direct extension into the pleural cavity, 20 patients with peritoneal mesothelioma and one patient with pleural mesothelioma were available for pharmacologic monitoring. After intraperitoneal or intrapleural administration of doxorubicin, plasma and peritoneal fluid samples were obtained at 15, 30, 45, 60 and 90 min in all patients. After intrapleural administration, plasma and pleural fluid samples were collected at similar intervals. Tumor and normal tissues were obtained when available. Doxorubicin concentrations were determined by high-performance liquid chromatography (HPLC).

RESULTS

Intraperitoneal doxorubicin showed a prolonged retention in the peritoneal cavity. Doxorubicin concentrations in tumor tissue were consistently elevated above intraperitoneal concentrations from 30 through 90 min. For appendiceal malignancy, the concentrations of doxorubicin were significantly higher in minimally aggressive mucinous tumors. Pleural chemotherapy solutions retained doxorubicin to a greater extent than peritoneal fluid.

CONCLUSIONS

Doxorubicin shows characteristics favorable for intracavitary administration with sequestration of doxorubicin in cancer nodules.

Quality of life after cytoreductive surgery plus early intraperitoneal postoperative chemotherapy for pseudomyxoma peritonei: a prospective study

PURPOSE

The modern treatment of pseudomyxoma peritonei is cytoreductive surgery plus intraperitoneal chemotherapy resulting in a survival of up to 70 percent after 20 years. The goal of this study was to investigate the impact on quality of life of this very aggressive treatment, which has not been done before.

METHODS

Twenty-three prospective patients underwent cytoreductive surgery and early postoperative intraperitoneal chemotherapy for pseudomyxoma peritonei. Patients were followed in clinic 3, 6, 12, 18, and 24 months after surgery and had CT scan of the abdomen every 6 months. Quality of life was prospectively assessed with the generic quality of life instrument Short Form-36 Questionnaire, together with the two symptom-specific instruments--European Organization for Research and Treatment of Cancer Quality of Life Questionnaire Core 30, and Colorectal Cancer Module 38--before surgery and at every postoperative visit.

RESULTS

Complete cytoreduction was achieved in 21 patients. No patients died within 30 days. Seventy percent of patients had one or more complications during or after surgery, but all had recovered. Fourteen percent had an asymptomatic recurrence detected within two years. The impact on quality of life of the disease and of its treatment was very modest despite the high morbidity after the treatment. There was a significant decrease in the scores on the Short Form-36 Questionnaire scales of physical dimension and role physical three months after surgery, only returning to normal after another three months. The other scores corresponded to the scores in a normal population.

CONCLUSIONS

Cytoreductive surgery plus early postoperative intraperitoneal chemotherapy is an extensive treatment with a high morbidity but with relatively little impact on quality of life in patients with pseudomyxoma peritonei.

Ovarian mature teratomas with mucinous epithelial neoplasms: morphologic heterogeneity and association with pseudomyxoma peritonei

Mucinous epithelial neoplasms arising in association with mature teratomas are a heterogeneous group of tumors, but with the exception of a single recent study, their full histologic spectrum, detailed immunophenotype, and association with classic pseudomyxoma peritonei (PMP) have not been fully studied. The morphologic, immunohistochemical, and clinical features of 42 patients with mucinous epithelial tumors arising in association with mature ovarian teratomas were evaluated. The patients' ages ranged from 17 to 66 years (mean, 39 y). Tumor size ranged from 5.5 to greater than 200 cm. Most teratoma-associated mucinous tumors were unilateral, although 1 patient harbored bilateral mucinous tumors in association with bilateral teratomas. In all cases, the teratomatous component consisted of mature elements. Using the 2003 World Health Organization criteria for ovarian intestinal type mucinous neoplasms, 17 (40%) were classified as mucinous cystadenoma, 16 (38%) as intestinal-type mucinous epithelial neoplasm of low malignant potential (IM-LMP), 4 (10%) as intraepithelial carcinoma (IEC), and 5 (12%) as invasive mucinous carcinoma. Mucinous cystadenomas had a varied epithelial lining consisting of lower gastroenteric, gastric foveolar, or müllerian appearance. In contrast, the IM-LMP, IEC, and invasive carcinoma cases had a more uniform lower gastroenteric histology. For mucinous cystadenomas, a cytokeratin (CK) 7+/CK20- phenotype (5/13; 38%) was equally as common as a CK7-/CK20+ phenotype (5/13; 38%), with the remaining cases coexpressing both keratins (CK7+/CK20+: 3/13; 23%). In contrast, IM-LMP, IEC, and invasive adenocarcinomas more frequently had a CK7-/CK20+ phenotype (56%, 50%, and 100%, respectively). A CK7+/CK20-phenotype was rare in these later 3 morphologic groups (6%). Of the 42 total cases, 55% had pseudomyxoma ovarii and 24% had classic PMP (1 cystadenoma, 6 IM-LMP, and 3 invasive carcinomas), whereas 5% had more localized accumulations of peritoneal mucin (both IM-LMP). Pathologic evaluation of the peritoneum in these 12 cases revealed 6 with acellular mucin alone, 3 with low-grade mucinous epithelium (all 3 with ovarian IM-LMP), and 3 with high-grade mucinous carcinomatosis (all 3 with ovarian mucinous adenocarcinoma). No appendiceal lesions were identified. Follow-up was available in 48% of patients (mean, 61 mo). The only adverse outcomes occurred in the 3 patients with ovarian carcinoma and associated peritoneal carcinomatosis. We report that a significant proportion of mucinous tumors associated with mature ovarian teratomas present with clinical PMP, which in most cases is associated with IM-LMP. PMP in this setting may harbor microscopic intra-abdominal low-grade mucinous epithelium that is histologically and immunophenotypically similar to that typically seen in appendiceal-related PMP. Pseudomyxoma ovarii is common in this setting, particularly in tumors with IM-LMP histology, but pseudomyxoma ovarii is not predictive of PMP. Ovarian teratoma-associated benign and IM-LMP mucinous neoplasms with microscopic peritoneal low-grade mucinous epithelium do not seem to be at significant risk for intra-abdominal recurrence, but numbers are few and follow-up is limited. In contrast, teratomas with an invasive carcinomatous component and microscopic peritoneal carcinomatosis follow an aggressive clinical course.

Organizing mucinous ascitis masquerading as pseudomyxoma peritonei: a process possibly caused by metaplasia but not neoplasia

Mucinous ascitis can be differentiated from the more ominous condition pseudomyxoma peritonei microscopically by the absence of epithelial cells amidst mucin pools in the former. Herein we communicate a brief report of organizing mucinous ascitis in a 34-year-old woman, with recurrent abdominal pain localized to right iliac fossa. Imaging studies were suggestive of mucocele. Conservative management, followed by appendicectomy and enbloc removal of the surrounding mucinous adhesions, was performed. Histopathology revealed chronic obliterative appendicitis, along with presence of mucin pools, mixed inflammatory cells and reactive mesothelial cells in the surrounding peri-appendiceal tissue. There was an absence of morphologically well-defined, neoplastic epithelial cells in the mucinous pool, thus excluding the diagnosis of pseudomyxoma peritonei. The problem of reactive mesothelial cells, which at places look like epithelial cells, was solved by a panel of immunohistochemistry. The localized mucinous ascitis possibly have originated from the mucinous metaplasia of the mesothelial lining cells of the peritoneum, secondary to recurrent attacks of appendicitis.

Pseudomyxoma peritonei: is disease progression related to microbial agents? A study of bacteria, MUC2 AND MUC5AC expression in disseminated peritoneal adenomucinosis and peritoneal mucinous carcinomatosis

BACKGROUND AND AIMS

Pseudomyxoma peritonei (PMP) is characterized by peritoneal tumors arising from a perforated appendiceal adenoma or adenocarcinoma, but associated entry of enteric bacteria in the peritoneum has not been considered as a cofactor. Because Gram-negative organisms can upregulate MUC2 mucin gene expression, we determined whether bacteria were detectable in PMP tissues.

METHODS

In situ hybridization was performed on resection specimens from five control subjects with noninflamed, nonperforated, non-neoplastic appendix and 16 patients with PMP [six with disseminated peritoneal adenomucinosis (DPAM) and 10 with peritoneal mucinous carcinomatosis (PMCA)]. Specific probes were designed to recognize: (1) 16S rRNA common to multiple bacteria or specific to H. pylori; (2) H. pylori cagA virulence gene; or (3) MUC2 or MUC5AC apomucins. Specimens from one patient with PMCA were examined by ultrastructural immunohistochemistry. Bacterial density and apomucin expression were determined in four histopathological compartments (epithelia, inflammatory cells, stroma, and free mucus).

RESULTS

Enteric bacteria were detected in all specimens. Bacterial density and MUC2 expression were significantly (p < 0.05) higher in PMCA than in DPAM and controls and were highest in free mucin. MUC2 was also expressed in dysplastic epithelia and in associated inflammatory cells. MUC2 expression was significantly correlated with bacterial density.

CONCLUSIONS

Multiple enteric bacteria are present in PMP, and bacterial density and MUC2 expression is highest in the malignant form of PMP. Based on these observations, we propose that the bacteria observed in PMP may play a role in the mucinous ascites and perhaps promote carcinogenesis.

Pathogenesis of ovarian cancer: lessons from morphology and molecular biology and their clinical implications

The accepted view of ovarian carcinogenesis is that carcinoma begins in the ovary, undergoes progressive "dedifferentiation" from a well to a poorly differentiated tumor, and then spreads to the pelvic and abdominal cavities before metastasizing to distant sites. It has therefore been reasoned that survival for this highly lethal disease could be improved by developing screening methods that detect disease when it is confined to the ovary. To date, however, no prospective randomized trial of any ovarian cancer screening test(s) has demonstrated a decrease in mortality. We believe that one of the main reasons for this is that the dogma underlying ovarian carcinogenesis is flawed. Based on studies performed in our laboratory during the last decade, we have proposed a model of ovarian carcinogenesis that takes into account the diverse nature of ovarian cancer and correlates the clinical, pathological, and molecular features of the disease. In this model, ovarian tumors are divided into 2 groups designated type I and type II. Type I tumors are slow growing, generally confined to the ovary at diagnosis, and develop from well-established precursor lesions that are termed "borderline" tumors. Type I tumors include low-grade micropapillary serous carcinoma, mucinous, endometrioid, and clear cell carcinomas. They are genetically stable and are characterized by mutations in a number of different genes including KRAS, BRAF, PTEN, and beta-catenin. Type II tumors are rapidly growing highly aggressive neoplasms for which well-defined precursor lesions have not been described. Type II tumors include high-grade serous carcinoma, malignant mixed mesodermal tumors (carcinosarcomas), and undifferentiated carcinomas. This group of tumors has a high level of genetic instability and is characterized by mutation of TP53. The model helps to explain why current screening techniques, aimed at detecting stage I disease, have not been effective. Tumors that remain confined to the ovary for a long period belong to the type I group, but they account for only 25% of the malignant tumors. Most of what is considered ovarian cancer belongs to the type II category, and these are only rarely confined to the ovary. Although the reasons for this are not entirely clear, possible explanations include rapid spread from the ovary early in carcinogenesis and development of carcinoma in extra ovarian sites, notably, the peritoneum and fallopian tube, with secondary involvement of the ovary. The latter tumors are advanced stage at their inception. Therefore, a more realistic end point for the early detection of ovarian cancer is volume and not stage of disease. The model does not replace the histopathologic classification but, by drawing attention to the molecular genetic events that play a role in tumor progression, sheds light on new approaches to early detection and treatment.

Minimally invasive intraductal papillary-mucinous carcinoma of the pancreas: clinicopathologic study of 104 intraductal papillary-mucinous neoplasms

Invasive intraductal papillary-mucinous carcinoma (I-IPMC) is a heterogeneous entity with various postoperative outcomes. The aim of this study is to characterize early-stage I-IPMC with nonaggressive characteristics. One hundred and four patients with intraductal papillary-mucinous neoplasm (IPMN) were clinicopathologically investigated. The lesions were classified into 53 noninvasive IPMNs (adenoma, borderline, and noninvasive IPMC) and 51 I-IPMCs on the basis of the WHO classification. I-IPMCs were divided further into 26 minimally invasive IPMCs (MI-IPMCs) and 25 invasive carcinomas originating in IPMC (IC-IPMCs) by new diagnostic criteria proposed in this study. We examined invasiveness of I-IPMC on 4 patterns, and defined simple and practical diagnostic criteria of minimal invasion for each invasive pattern. The disease-specific survival rates after 3, 5, and 10 years were 100%, 100%, and 100% for both noninvasive IPMN and MI-IPMC, and 51%, 38%, and 0% for IC-IPMC. The overall and disease-specific survival rates for MI-IPMC were both significantly better than those for IC-IPMC (P<0.001), but there was no significant difference between noninvasive IPMN and MI-IPMC. Multivariate analysis showed that the factors indicative of poor prognosis were a diagnosis of I-IPMC classified as IC-IPMC and a high level of serum carbohydrate antigen 19-9. The prognosis of IC-IPMC was not significantly different from that of pancreatic ductal carcinoma in each of the corresponding tumor-node-metastasis stages. These findings suggest that a category of MI-IPMC provides more accurate and useful information of the stage and the aggressiveness of I-IPMC.

Discordant histology of primary appendiceal adenocarcinoid neoplasms with peritoneal dissemination

BACKGROUND

Adenocarcinoid is a rare appendiceal tumor that shows histologically both epithelial and neuroendocrine components. We observed that some patients have peritoneal dissemination, which shows adenocarcinoma but lacks the neuroendocrine histology. The objective of the present study was to quantitate these discordant histopathological findings and examine its clinical implication.

METHODS

Twenty-six patients with peritoneal dissemination from primary appendiceal adenocarcinoid tumors underwent cytoreductive surgery and perioperative intraperitoneal chemotherapy. All resected specimens were individually submitted for histopathological examination and immunostaining with three neuroendocrine markers. The anatomic locations for peritoneal implants were prospectively recorded. The loss of the neuroendocrine tumor type in peritoneal implants was referred to as discordant feature of the adenocarcinoid tumor. Clinical and histopathological prognostic factors for survival were analyzed.

RESULTS

In nine of the 26 patients (35%) with a primary adenocarcinoid of the appendix, a loss of the neuroendocrine immunochemical marker was noted in peritoneal implants. Discordant histology between the primary appendiceal adenocarcinoid and the peritoneal implants was statistically significantly associated with an improved survival (p = 0.0262), when patients were treated by cytoreductive surgery and perioperative intraperitoneal chemotherapy.

CONCLUSIONS

Discordant histology of the primary appendiceal tumor as compared to the peritoneal lesions occurs frequently in patients with adenocarcinoid. An assessment of neuroendocrine markers in both primary and peritoneal lesions may help in the clinical assessment of this group of patients. Small numbers of patients were available for this study and the conclusions are therefore limited.