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"

Pseudomyxoma peritonei (PMP) is a poorly understood condition characterized by mucinous ascites and mucinous implants diffusely involving the peritoneal surfaces. There is considerable debate regarding the definition, pathology, site of origin, and prognosis of PMP. We analyzed the clinicopathologic features of 109 cases of multifocal peritoneal mucinous tumors to develop a pathologic definition of cases characterized by the clinical condition PMP. Cases were separated into two diagnostic categories: disseminated peritoneal adenomucinosis (DPAM) and peritoneal mucinous carcinomatosis (PMCA). Cases classified as DPAM were characterized by peritoneal lesions composed of abundant extracellular mucin containing scant simple to focally proliferative mucinous epithelium with little cytologic atypia or mitotic activity, with or without an associated appendiceal mucinous adenoma. Cases classified as PMCA were characterized by peritoneal lesions composed of more abundant mucinous epithelium with the architectural and cytologic features of carcinoma, with or without an associated primary mucinous adenocarcinoma. Sixty-five of the 109 cases (59.6%) were classified as DPAM consistent with origin from an appendiceal mucinous adenoma. Thirty-seven of the 65 cases (56.9%) had a documented appendiceal mucinous adenoma. Thirty cases (27.5%) were classified as PMCA consistent with origin from an appendiceal or intestinal mucinous adenocarcinoma. Fourteen cases (12.8%) were classified as PMCA with features intermediate between DPAM and PMCA or with discordant features based on the finding of at least focal areas of carcinoma in the peritoneal lesions, whether or not the primary site demonstrated carcinoma. The cases with intermediate features were derived from well-differentiated appendiceal or intestinal mucinous adenocarcinomas and had peritoneal lesions displaying features of DPAM as well as focal areas of mucinous carcinoma. The cases with discordant features were derived from atypical appendiceal adenomas with little or no histologic evidence of a transition from adenoma to carcinoma and had peritoneal lesions uniformly composed of mucinous carcinoma. There was a statistically significant difference in survival between cases classified as DPAM, those classified as PMCA with intermediate or discordant features, and those classified as PMCA (p < 0.0001). The age-adjusted 5-year survival rates were 84% for patients with DPAM, 37.6% for patients with PMCA with intermediate or discordant features, and 6.7% for patients with PMCA. The term DPAM should be used to diagnose the histologically benign peritoneal lesions associated with ruptured appendiceal mucinous adenomas and those that are pathologically identical but lack a demonstrable appendiceal adenoma. Cases with the pathologic features of adenocarcinoma should be designated PMCA because they have recognizably different pathologic features and a significantly worse prognosis.

Pseudomyxoma peritonei of appendiceal origin: a clinicopathologic analysis of 101 patients uniformly treated at a single institution, with literature review

Pseudomyxoma peritonei is a clinical term for gelatinous ascites, usually secondary to an appendiceal tumor. The pathologic classification of pseudomyxoma peritonei and its associated appendiceal tumors has been plagued with controversy and confusing terminology. In an effort to clarify this, we reviewed the pathology of 101 patients, all treated at our institution from 1993 to 2005, with pseudomyxoma peritonei of appendiceal origin. All patients were uniformly treated with our standardized protocol. This is the largest pathologic series solely devoted to appendiceal neoplasia with gelatinous ascites. The cases were assigned, according to previously published criteria, to the categories of disseminated peritoneal adenomucinosis (DPAM), peritoneal mucinous carcinomatosis (PMCA), or PMCA with intermediate (well differentiated) features (PMCA-I), with the exception that any case with a signet-ring cell component was considered as PMCA and not PMCA-I. By histologic category, 58 patients had DPAM, 23 were PMCA, and 20 were PMCA-I.One-year, 3-year, and 5-year survival outcomes were not significantly different between DPAM and PMCA-I. DPAM and PMCA-I also exhibited a roughly equal incidence of parenchymal (beyond the serosa) organ invasion. Survival outcomes were significantly worse for PMCA, compared with PMCA-I and DPAM. After reviewing our data and the literature, mucinous carcinoma peritonei-low grade was applied to the low-grade histology of pseudomyxoma peritonei, including those cases referred to by some as DPAM in the same category as PMCA-I. Cases that are moderately differentiated to poorly differentiated are classified as mucinous carcinoma peritonei-high grade.

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'

Mucinous ovarian neoplasms other than cystadenomas and adenofibromas have been classified as either borderline tumors or carcinomas for many years. Borderline tumors have been subdivided more recently into endocervical-like (mullerian) and intestinal forms. Such a distinction is rarely made in the mucinous carcinoma category. We did not encounter a pure endocervical-like carcinoma in the present series. Criteria for distinguishing an intestinal-type mucinous borderline tumor from a mucinous carcinoma have been controversial. In this study of 164 mucinous borderline tumors of intestinal type and 32 mucinous carcinomas, the former were further subdivided into 74 cases with epithelial atypia only and 90 with focal intraepithelial carcinoma. Of the 67 stage I tumors in the borderline (with atypia) category, all 49 with follow-up data were clinically benign; in the seven cases that had been designated stage III, the intraoperative appearance was that of "pseudomyxoma peritonei," which was fatal in four cases. Most of these tumors, however, were probably metastatic to the ovary rather than truly primary borderline tumors, although failure to examine the appendix in six cases compromised their interpretation. All 90 mucinous borderline tumors that had foci of intraepithelial carcinoma were recorded as stage I, but two of the 69 patients with follow-up data (3%) had fatal recurrences. Both of these tumors were incompletely staged, however, and one had ruptured intraoperatively. Thirty-two invasive carcinomas were subdivided into 12 expansile and 20 infiltrative subtypes; within the latter category seven tumors were only microinvasive. All 12 carcinomas with only expansile invasion were stage I; none of the 10 with follow-up data recurred. All seven microinvasive infiltrative carcinomas were stage I; none of the five with follow-up data recurred. One of five patients with stage I infiltrative carcinomas that were more than microinvasive and were adequately followed had a fatal recurrence, but staging had been incomplete in that case. Seven of the remaining eight infiltrative carcinomas were higher than stage I: five of the six (83%) with follow-up data persisted or recurred and were fatal. Considering all stages, increasing tumor grade in the carcinoma category correlated with an unfavorable outcome. However, grade did not influence prognosis in stage I carcinomas. Among 13 stage I cases in all categories with either preoperative or intraoperative tumor rupture and follow-up data, one recurred, a tumor in the borderline with intraepithelial carcinoma category. "Pseudomyxoma peritonei" is an ill-defined term and should not be used as a pathologic diagnosis. The presence of mucin in the abdominal cavity requires careful histologic evaluation to characterize it for prognostic purposes. Adequate and sometimes extensive sampling of mucinous ovarian tumors, the appendix and the peritoneum in cases of "pseudomyxoma peritonei" is necessary to achieve an accurate diagnosis and prognosis.

Peritoneal implants of ovarian serous borderline tumors. Histologic features and prognosis

The clinicopathologic features of 56 cases of ovarian serous borderline tumors (SBT) associated with peritoneal implants were reviewed. Data from 368 person-years of follow-up (median follow-up, 6.0 years) were analyzed to investigate the possibility that the histologic features of implants of this type of tumor may correlate with the prognosis. Eighty-five percent of the 56 patients were clinically free of tumor at the time of death or at last contact. Thirteen percent of the patients died of tumor, and one patient (2%) was alive with widespread progressive tumor. The product-limit estimate of the probability of death from tumor (+/- standard error) was 4% (+/- 3%) at 5 years and 23% (+/- 9%) at 10 years. The following three histologic features of the implants correlated with an adverse prognosis: (1) invasion (P = 0.0004), (2) severe cytologic atypia in both invasive and noninvasive implants (P = 0.0008) and in noninvasive implants alone (P = 0.02), and (3) the presence of mitotic activity in both types of implants (P = 0.02) and in noninvasive implants alone (P = 0.02). The only other feature that correlated with the prognosis was the presence of residual tumor postoperatively as assessed by the surgeon (P = 0.01). The product-limit estimate of death of tumor in patients with at least one of these four adverse prognostic factors was 56% (+/- 20%) at 10 years. Whether or not the patients received radiation therapy, chemotherapy, or both had no statistically significant effect on the outcome. These data and the results of a stratified analysis suggest that patients may benefit from additional therapy if adverse prognostic factors are present, especially invasiveness or severe cytologic atypia. It is unlikely that additional therapy is necessary in patients without adverse prognostic features, because no deaths occurred in this group.

Intraperitoneal cancer dissemination: mechanisms of the patterns of spread

BACKGROUND

Well known patterns govern the distribution of hematogenous and lymphatic metastasis of cancer. In the past the distribution of cancer cells free within abdominal cavity received little attention and was thought to be a random event. However, surgical observation led the authors to generate and test hypotheses regarding patterns of spread that vary with tumor type, with the intraperitoneal environment, and with the physiology of the peritoneal surface tissues.

METHODS

The distribution and volume of peritoneal surface malignancy was prospectively recorded in 129 patients with 5 different types of tumors at the time of cytoreductive surgery. The malignancies studied included pseudomyxoma peritonei (PMP) of appendiceal origin, colonic mucinous adenocarcinoma (MA), nonmucinous colonic adenocarcinoma (NMA), ovarian carcinoma (OV) and sarcoma (SA). The abdominal and pelvic cavity was divided into 3 horizontal sectors, 9 regions and 25 sites. The incidences of tumor implants in these designated areas were statistically analyzed for each tumor type and comparisons between tumor types studied.

RESULTS

The magnitude of intraperitoneal cancer dissemination was similar for mucinous tumors, including PMP and MA and significantly higher than for non-mucinous tumors. Also the mucinous cancers were more likely to be present in the upper horizontal sector than were non-mucinous. When NMA was compared to PMP and MA the epigastric region was significantly less likely to contain tumor. For all cancer diagnoses the colon, greater omentum and cul-de-sac of Douglas were most often affected. The ileocecal valve region was more likely to have large tumor masses on its surface than small bowel surface or small bowel mesentery.

CONCLUSIONS

Peritoneal carcinomatosis had a wider distribution when mucinous fluid was present; this cancer distribution by intraperitoneal fluid hydrodynamics occurred regardless of histologic aggressiveness. The organs that have peritoneal fluid resorption (omentum and omental appendages) have a high incidence of implants. Small bowel and its mesentery free to move by peristalsis had a reduced incidence of implants as compared to the ileocecal area, which is fixed to the retroperitoneum. These observations may facilitate efforts to treat peritoneal surface malignancy.

Sarcomas and other malignancies of soft tissue, retroperitoneum, peritoneum, pleura, heart, mediastinum, and spleen

BACKGROUND

Malignant neoplasms of the structural tissues, consisting mostly of soft tissue sarcomas, are morphologically diverse and rarely treated for epidemiologic purposes as individual entities. Our understanding to date of the pattern of occurrence of sarcomas is based largely on reports of limited individual clinic experience or case-control studies, each driven by a single hypothesis, and there have been virtually no descriptions according to specific morphologic type.

METHODS

The accumulated coverage of the SEER populations offers an opportunity to correct this deficit. Each of the diagnoses has been reported and coded using a single set of rules and described in relation to the population at risk in terms of age, sex, race, calendar period, anatomic location, and outcome. In addition, each morphologic type has been compared with each of the others with respect to the pattern of occurrence and survival.

RESULTS

For most of the individual morphologic entities, the pattern of occurrence is specific and unlike other patterns. Differences according to anatomic site, age, sex, race, and period-specific survival were found. Partly because of changes in diagnostic criteria over the years, differences in secular trend, other than that for Kaposi's sarcoma, could not be verified. Although some types of sarcoma may have important genetic determinants, there is evidence of environmental causation in others; for some varieties both genetic and environmental factors may operate. There is no evidence of improvements in survival.

CONCLUSIONS

The most likely basis for the observed patterns are morphology-specific differences in etiology and growth phase. Each of the entities should be considered etiologically distinct and should be studied individually whenever possible.

Appendiceal mucinous tumors and pseudomyxoma peritonei: histologic features, diagnostic problems, and proposed classification

Pseudomyxoma peritonei is an overused and underspecified condition that has garnered much attention in the historic literature. In recent years, this condition has been convincingly linked to appendiceal mucinous neoplasms, yet there has been insufficient attention to the histologic characteristics, classification, and differential diagnostic considerations of these neoplasms when encountered by the surgical pathologist. This review provides a coherent approach to the diagnosis and classification of appendiceal mucinous tumors and the peritoneal implants associated with the pseudomyxoma peritonei syndrome with emphasis on differential diagnostic considerations and recommendations for the final pathology report.

Refined diagnostic criteria for implants associated with ovarian atypical proliferative serous tumors (borderline) and micropapillary serous carcinomas

Characterization of invasive peritoneal implants from patients with noninvasive serous ovarian tumors has important prognostic and treatment implications, but the criteria for distinguishing invasive and noninvasive implants vary among investigators and can be difficult to apply. The authors studied 148 implants from 60 patients, 33 with primary atypical proliferative serous tumor, and 27 with primary noninvasive micropapillary serous carcinoma, with a mean follow-up of 62 months (median follow-up, 52 months). Previously reported and newly proposed histologic features for implant classification were evaluated and correlated with clinical outcome. Three criteria were applied for the diagnosis of "invasive" implants: invasion of underlying normal tissue, micropapillary architecture, and solid epithelial nests surrounded by clefts. Implants displaying any one of these three features were classified as "invasive," whereas those lacking all three features were classified as "noninvasive." Sixty-six implants were invasive and 82 were noninvasive. Of the 31 patients with invasive implants, six were dead of disease (DOD), 13 were alive with progressive disease (AWPD), and 12 were alive with no evidence of disease (NED). Of the 29 patients with noninvasive implants, two were DOD, one was dead of uncertain causes, one was AWPD, and 25 were alive with NED. Eighty-nine percent of invasive implants had a micropapillary architecture and 83% had solid epithelial nests surrounded by clefts. A minority of invasive implants (14% of those with underlying normal tissue) demonstrated invasion of normal underlying tissue. Nuclear atypia, mitoses, calcification, necrosis, and identification of individual cells "infiltrating" the stroma did not correlate with implant type. The proposed criteria permitted recognition of implants that correlated strongly with adverse outcome. Sixty-one percent of patients with implants displaying any one of the three features used to diagnose invasive implants were AWPD or DOD compared with 10% of patients whose implants lacked these features (p = 0.00001). Because implants associated with an adverse outcome can be identified before they invade underlying normal tissue, the term invasive implant to describe them is inaccurate and misleading. These implants resemble patterns of growth in micropapillary serous carcinoma of the ovary and the recurrent tumor that is obvious carcinoma. Accordingly, we propose that these extraovarian lesions be designated "well-differentiated serous carcinoma."

Diffuse malignant mesothelioma of the peritoneum and pleura, analysis of markers

Diffuse malignant mesothelioma of the peritoneum is a rare diagnosis. Despite many histopathologic similarities between peritoneal and pleural tumors, clinical and prognostic features may be quite different. There is a paucity of data evaluating molecular features of peritoneal mesotheliomas. Therefore, we compared the results of a battery of immunohistochemical markers, some with therapeutic implications, in patients with primary peritoneal or pleural mesotheliomas. We examined 24 peritoneal and nine pleural malignant mesotheliomas with a battery of immunohistochemical markers (cytokeratin AE1/3, calretinin, c-kit/CD117, desmin, epidermal growth factor receptor (EGFR), estrogen receptors (ER), progesterone receptors (PR), MIB-1, and cleaved caspase-3) in an attempt to distinguish any differences in this tumor arising in these two distinct locations. The results indicate that the only marker to show a significant difference in its staining pattern between these two sites was EGFR (P=0.0004). In all, 92% (22/24) of peritoneal tumors demonstrated 3+ or 4+ immunoreactivity with EGFR, opposed to only 33% (3/9) pleural tumors. There was no significant difference in immunoreactivity between the pleural and peritoneal tumors with c-kit, ER, PR, cleaved caspase 3, calretinin, and desmin. There was a trend toward increased cytokeratin (P=0.07) and MIB-1 (P=0.08) expression in the peritoneal group. There was no significant difference in age, sex, or histologic subtype between the two locations. In conclusion, despite similarities between peritoneal and pleural mesothelioma, there are differences between this neoplasm arising in these two sites. The EGFR expression is more pronounced in peritoneal tumors compared to pleural tumors. The increased expression of EGFR in the peritoneal lesions may be of clinical significance with the recent emergence of epidermal growth factor receptor-targeted therapies.

CDX-2 expression in pseudomyxoma peritonei: a clinicopathological study of 42 cases

AIMS

CDX-2 is a highly sensitive and specific marker of intestinal epithelial cells and their neoplastic counterparts. CDX-2 status in pseudomyxoma peritonei (PMP) has been barely reported. The aim of this study was to investigate the clinicopathological features of 42 cases of PMP with a special emphasis on CDX-2.

METHODS AND RESULTS

All patients were treated by cytoreduction. Immunohistochemistry was performed for CDX-2, MUC-2, MUC-5AC, cytokeratin (CK) 7 and CK20. Statistical correlation was evaluated for age, sex, completeness of cytoreduction and histological subtype with overall and progression-free survival (OS and PFS). PMP consisted of 32 cases of disseminated peritoneal adenomucinosis and 10 cases of peritoneal mucinous carcinomatosis. The appendix evaluated in 25 cases showed two mucinous adenocarcinomas and 21 low-grade appendiceal mucinous neoplasms. CDX-2 was diffusely positive in 40 cases, with the remaining two cases being focally positive. All cases demonstrated diffuse reactions to CK20 and MUC-2, and variable reactions to MUC-5AC, while CK7 was variably positive in 38 cases. Five-year OS was 97%. Histological type was significantly correlated with PFS (P=0.02).

CONCLUSIONS

CDX-2 is diffusely and strongly positive in PMP. This is a useful marker to confirm an appendiceal origin of PMP, particularly when used in conjunction with CK7, CK20, MUC-2 and MUC-5AC.

Mesodermomas: a new embryological approach to primary tumours of coelomic surfaces

It appears that the so-called mesothelium lining the serous cavities is in fact mesoderm, with an epithelial-like arrangement which persists in the post-embryological stage. Cellular variability of primary tumours of serous surfaces can be explained on this developmental evidence. The term mesodermoma seems to be justified to define neoplasms arising from undifferentiated and multipotential mesoderm which, in neoplastic disease, exhibits a wide range of differential activity and gives rise to tumours with prevailing myoblastic, angioblastic, lymphoblastic, chondroblastic, osteoblastic, fibroblastic or epithelial-like features.

Gastrointestinal autonomic nerve tumours: a report of nine cases

We describe the clinicopathological features of gastrointestinal autonomic nerve tumours in nine patients where the diagnosis was confirmed by electronmicroscopy. Most patients presented with abdominal pain. At laparotomy, large intra-abdominal tumour masses were found which tended to be cystic and haemorrhagic. The predominant histological patterns were nests, sheets and fascicles of spindle and epithelioid cells. Immunohistochemistry showed positive staining for neuron specific enolase (9/9), PGP 9.5 (9/9), NKI/C3 (7/9), vimentin (7/9), alpha-smooth muscle actin (5/9), vasoactive intestinal peptide (3/9) and CD34/QBend10 (2/9). Grimelius staining was positive in two of nine cases. All tumours were negative for CAM 5.2, chromogranin, synaptophysin, Leu 7, neurofilament protein, muscle-specific actin (HHF-35) and desmin (D33). Ultrastructural examination showed cellular processes and dense-core granules in all cases. Three tumours had microtubules and/or intermediate filaments, particularly in cell processes. Skeinoid fibres were seen in three cases. No convincing synapses or small (synaptic-type) vesicles were identified. There was no evidence of epithelial, smooth muscle or nerve sheath differentiation. Two patients died due to tumour, two died of unknown causes and the remainder are alive 2-44 months after presentation. Four of the five survivors have recurrent/residual intra-abdominal tumour. So-called gastrointestinal autonomic nerve tumours are apparently slow-growing malignant tumours showing neuronal differentiation. Four cases arose in the mesentery/retroperitoneum or omentum rather than bowel wall and therefore a more appropriate nomenclature might be intra-abdominal stromal tumour with neuronal differentiation.

Computed Tomographic Characterization of Malignant Peritoneal Mesothelioma

Aims and Background

Peritoneal mesothelioma is a rare disease with a universally fatal outcome when managed in a traditional palliative manner. New approaches to treatment using cytoreductive surgery and intraperitoneal chemotherapy suggest that long-term survival is possible in selected patients. Early recognition of this disease process with an orderly surgical approach will begin to optimize treatment.

Methods

Thirty-three patients with malignant peritoneal mesothelioma had CT scans available for review. A Z-score was used to evaluate the incidence of cancer at a particular anatomic site as compared to a general incidence of disease at all sites. CT was analyzed by abdominopelvic anatomic sites (16), abdominopelvic regions (9), and for presence versus absence of disease in the chest. Interpretative CT findings (class 0-III) were determined for these 33 patients.

Results

Eight of 33 patients had pleural abnormalities. In an analysis of 16 abdominopelvic anatomic sites, the vesical or rectal uterine pouch was involved in 97% and the greater omentum in 91%. These anatomic sites were the only ones with a positive Z-score of >1. In the analysis of 9 abdominopelvic regions, the central and pelvic regions had Z-scores >2 for large volume disease >5 cm. For CT interpretative findings class I, class II and class III was determined in approximately one-third in each category. Sixty-six percent of the patients had ascites by CT.

Conclusions

Malignant peritoneal mesothelioma by CT evaluation predominates in tumor mass within the central and pelvic portions of the abdomen. Minimal, moderate, and extensive small bowel enlargements were seen in roughly one-third of the patients. With the use of the Z-score and interpretative small bowel findings a radiologic characterization of this disease for primary radiologic diagnosis is possible.

Metastases-related genes in the classification of liver and peritoneal metastasis in human gastric cancer

INTRODUCTION

With the aim of identifying metastases-related genes in gastric cancer, we performed a broad analysis of differential gene expression between low-metastatic parental cell lines and established highly metastatic sublines.

MATERIALS AND METHODS

We established novel cell lines, AZ-H5c, NUGC-3H5, and TMK-1H7, with a high potential of liver metastasis, and AZ-P7a, NUGC-3P4T, and TMK-1P4a, with a high potential of peritoneal metastasis. These cell lines were derived from low-metastatic parental AZ-521, NUGC-3, and TMK-1 cell lines, respectively. Furthermore, to investigate different levels of gene expression implicated in metastatic potentials in gastric cancer, we investigated approximately 2000 expressed genes in each cell line using a DNA microarray.

RESULTS

Varieties of genes were up-regulated or down-regulated in highly metastatic liver and peritoneal cell lines. Fifty-eight genes, including the transferrin receptor, ras-related rho, and osteopontin, and 22 genes, including apolipoprotein E and inhibin A-submit, were up-regulated and down-regulated in two or three liver metastatic sublines. On the other hand, 19 genes, the transferrin receptor, c-fos, and RANTES, and 26 genes, including MAC25, PISSLRE, and RNA polymerase, were up-regulated and down-regulated in two or three peritoneal metastatic sublines.

CONCLUSION

How gene expression is implicated in gastric cancer metastasis has never been thoroughly explained, and further studies are necessary to understand the involvement of genes in cancer metastasis more thoroughly. We hope that our highly metastatic liver and peritoneal experimental models are helpful for further study and gene therapy of human gastric cancer.

Endometrial stromal sarcoma with focal smooth muscle differentiation: recurrence after 17 years: a follow-up report with discussion of the nomenclature

In 1977, a case report was published describing a 28-year-old women with an endometrial stromal tumor that showed foci of myogenic differentiation. The term "stromomyoma" was introduced to encompass both this type of neoplasm as well as "uterine neoplasms resembling ovarian sex-cord tumors" (UTROSCTs). More than 17 years later, the tumor recurred, involving the right ovary, sigmoid colon, small bowel, abdominal wall and omentum. The histologic and electron microscopic similarities between the recurrent tumor and the primary neoplasm were confirmed. Applying the recent classification and diagnostic criteria of endometrial mesenchymal neoplasms, we have concluded that this tumor was a low-grade endometrial stromal sarcoma (LGSS). The formerly proposed term "stromomyoma" implies a benign tumor, in contrast to the obviously malignant nature of this particular tumor. Focal myogenic differentiation of LGSS is not an uncommon finding and does not warrant a separate diagnostic or prognostic entity. UTROSCTs and endometrial stromal sarcomas are two separate diagnostic entities, and combining them under an inclusive terminology is not appropriate.

Surgical treatment of neuroblastomas in infants under 12 months of age

BACKGROUND

Surgical treatment of neuroblastomas, both those detected by screening and those detected clinically, in infants less than 12 months of age, is controversial, because some tumors in this age group potentially have the ability to regress spontaneously.

METHODS

From January 1985 to March 1997, the authors treated 50 infants (under 1 year of age) with neuroblastoma: 23 boys and 27 girls. Forty-one cases were detected preclinically by screening when the patients were 6 to 11 months of age (median, 7 months), and nine patients were discovered to have clinical manifestations at the age of 1 to 10 months (median, 4 months).

RESULTS

The tumor was INSS stage 3 or 4 in 10 patients (24%) with screening-detected tumor and in five (56%) with clinically detected tumor, although the difference was not statistically significant. Four screening-positive patients had multifocal primary tumors, and three of them were synchronous bilateral adrenal neuroblastomas. There was no statistically significant difference between the screening-detected tumors and the clinically detected tumors in biological characteristics such as Shimada's histology, DNA ploidy, and N-myc amplification. Complete resection of the primary lesion was accomplished by either primary surgery or second look (delayed primary) surgery in 46 patients (92%), and the resection was incomplete in the remaining four. In patients with bilateral adrenal tumors, the larger one was primarily resected, and the smaller contralateral tumor was enucleated or resected by partial adrenalectomy. Surgical complications included postoperative adhesive ileus (n=2), Horner's syndrome (n=2), renal atrophy (n=1), renal failure (n=1), phrenic nerve injury (n=1), chylous ascites (n=1), chylothorax (n=1) and intussusception (n=1). One patient died of respiratory failure caused by a complication, but 49 patients (98%) were alive at the time of evaluation.

CONCLUSION

When considering surgical treatment of infants with biologically favorable neuroblastoma, the risk involved in treatment should be weighed against the risk inherent in a tumor capable of spontaneous regression, and aggressive surgery is unacceptable.

Controversy and consensus on the management of patients with pseudomyxoma peritonei

OPINION STATEMENT

Pseudomyxoma peritonei and peritoneal carcinomatosis derived from appendiceal epithelial tumors are controversial entities from classification to treatment. For the former entity, multiple classification systems have been attempted to distinguish indolent from more aggressive subtypes. The treatment of the low grade variants is managed with serial cytoreduction surgery, with data indicating possible, but unproven, benefit from heated intraperitoneal chemotherapy (HIPEC). There is no consensus on the role of cytoreduction and HIPEC for the management of the more aggressive histologic variants and peritoneal carcinomatosis. Currently, we believe systemic chemotherapy is the standard of care for patients with the high grade variants and peritoneal carcinomatosis.

Can low grade PMP be divided into prognostically distinct subgroups based on histological features? A retrospective study and the importance of using the appropriate classification

INTRODUCTION

The pathological classification of PMP of appendiceal origin has prognostic and treatment implications. Our goals were to • Classify low grade mucinous carcinoma peritonei (LGMCP) into prognostically distinct subgroups based on histological features. • Compare the reproducibility of the WHO and the PSOGI classifications for both PMP and the appendiceal primary tumor.

PATIENTS AND METHODS

A retrospective analysis of patients undergoing CRS and HIPEC or debulking surgery was done. All the tumors were re-classified according to the PSOGI classification. LGMCP was further classified into three histological subgroups and the impact on survival was evaluated.

RESULTS

From Jun 2011 to June 2016, 101 patients underwent CRS with HIPEC (n = 89) or debulking surgery (n=12). The median PCI was 28 (3-39) and 74.1% patients had CC-0/1 resections. Of the 76.2% patients who had LGMCP, 4 patients (5.1%) were classified as group 1, 54 (70.1%) as group 2 and 19 patients (24.6%) as group 3. At a median follow up of 21 months, the disease free survival was not reached, 30 months and 14 months for groups 1, 2 and 3 respectively (p = 0.09). There was no difference in overall survival. Using the WHO classification, there was a discordance in the grade of the primary tumor and the peritoneal lesions in 19.8% and conflicting terminology was used in 62% of patients.

CONCLUSIONS

The subgroups of LGMCP described here are prognostically different though this needs further prospective evaluation in larger series. The PSOGI classification is more uniformly reproducible and should be preferred to the WHO classification.

Peritoneal mesotheliomas in Danish women: review of histopathologic slides and history of abdominal surgery

An unexpectedly large number of peritoneal mesotheliomas among women was reported to the Danish Cancer Registry during the years 1960 through 1985. In a case-control study, we tested whether this was due to diagnostic misclassification or to direct exposure of the peritoneal membranes to talc during abdominal surgery. Tissue specimens were available from 96 reported peritoneal mesotheliomas; 35 cases (37%) were regarded as verified mesotheliomas, and 33 (34%) as possible mesotheliomas. Information on any intraabdominal surgery was obtained from the hospital records of these 68 cases and for 206 controls with a cancer of the uterine corpus or pancreas. No association was seen between peritoneal mesotheliomas and abdominal surgery performed more than 25 years prior to cancer diagnosis (odds ratio, 0.83; 95% confidence interval, 0.35-1.94). CONCLUSION. Misclassification of other cancers was the reason for the observed excess of peritoneal mesotheliomas.

[Peritoneal pseudomyxoma: an overview emphasizing pathological assessment and therapeutic strategies]

Pseudomyxoma peritonei is a clinical entity characterized by a gelatinous ascite associated with mucinous tumor deposits spreading on peritoneal surface and potentially invading abdominal organs. It is considered as a tumor process linked, in most of cases, to a mucinous appendiceal neoplasm. Pseudomyxoma peritonei may benefit from a therapeutic strategy combining cytoreductive surgery and intra-peritoneal chemotherapy, which has led to a major prognosis improvement. Different classifications are available and the last one corresponds to the WHO 2010 version, which individualizes pseudomyxoma peritonei in two classes: low grade and high grade mucinous carcinoma. The very low frequency of this entity and its specific therapeutic strategy need specific health care centres, as well as physicians and pathologists collaborating through dedicated networks. The aim of this article is to summarize the pathology, causes, mechanisms and therapeutic approaches of pseudomyxoma peritonei, as well as their interfaces with dedicated networks.

Ascitic fluid analysis: the role of biochemistry and haematology

In specific settings, biochemical and haematological analysis of ascitic fluid may provide answers to important clinical questions. This review seeks to outline the value and limitations of ascitic fluid analysis and the main clinical scenarios in which it may be useful.

Validation of Revised FIGO Staging Classification for Cancer of the Ovary, Fallopian Tube, and Peritoneum Based on a Single Histological Type

OBJECTIVE

This study aimed to evaluate the prognostic significance of revised International Federation of Gynecology and Obstetrics (FIGO2013) staging classification for cancer of the ovary, fallopian tube, and peritoneum in patients exhibiting high-grade serous histology.

METHODS

Clinical records of patients with high-grade serous carcinoma who underwent primary surgery between 2007 and 2012 were reviewed retrospectively. Patients were reclassified according to the FIGO2013 criteria. Progression-free survival (PFS) and overall survival (OS) were calculated for each stage using Kaplan-Meier estimates and compared with the log-rank test.

RESULTS

In total, 125 patients were included in the analysis. The distribution of the study cohort according to the revised classification was as follows; stage I, 6 patients; stage II, 9 patients; stage III, 85 patients; and stage IV, 25 patients. Median follow-up time was 36 months (95% confidence interval [CI], 3-110). The median PFS and OS were 14 months (95% CI, 12.4-15.6) and 60 months (95% CI, 47.0-72.9), respectively. Both PFS and OS were significantly different among stages I, II, III, and IV (P < 0.01). Subgroup analyses for stage III disease also revealed significant differences in survival. The median PFS for stages IIIA1, IIIB, and IIIC was 56, 46, and 16 months, respectively (P < 0.01), and the median OS was 104, 95, and 60 months, respectively (P = 0.03). The outcomes of patients with stage IV disease differed slightly but nonsignificantly according to new substages. The median PFS for stages IVA and IVB was 12 and 6 months, respectively (hazard ratio, 1.16; 95% CI, 0.48-2.79; P = 0.72), and the median OS was 41 and 24 months, respectively (hazard ratio, 1.62; 95% CI, 0.58-4.55; P = 0.35). The study sample was insufficient in size for subgroup analyses in stages I and II.

CONCLUSIONS

The revised FIGO2013 staging system is highly prognostic for discriminating outcomes of patients with high-grade serous carcinoma across stages I to IV, in subgroups of stage III, but not in subgroups of stage IV.