Pancreatic, hepatic, splenic, and mesenteric mucinous cystic neoplasms (MCN) are lumped together as extra ovarian MCN

Mucinous Cystic Neoplasm of the Liver in a Teenager: A Case Report

Mucinous cystic neoplasms of the liver (MCN-Ls) are rare cystic liver tumors. Herein, we report a case of MCN-L wherein complete surgical resection was successful. A 17-year-old girl initially presented to the referring hospital with a chief complaint of upper abdominal pain. Abdominal computed tomography (CT) revealed a cystic lesion in the medial segment of the liver. After eight months, the cystic lesion showed a tendency to increase in size, and the patient was referred to our hospital. CT showed a cystic lesion with dilation of the left hepatic duct and duct of the right anterior segment. Magnetic resonance imaging and abdominal ultrasonography revealed a multilocular cyst. Endoscopic retrograde cholangiopancreatography revealed sclerotic changes, dilatation, and irregular wall features in the left hepatic duct. No communication between the cystic lesion and the biliary system was observed; there was no evidence of biliary prolapse. A left hepatectomy and cholecystectomy were performed. Histological examination revealed an ovarian-like stroma (OLS); the lesion was diagnosed as MCN-L. The patient was recurrence-free six months postoperatively.To our best knowledge, this is the second reported case of teenage-onset MCN-L. We report the development of MCN-L in a teenager, highlighting the potential of this rare tumor for manifesting even at a young age. Our case demonstrated that MCN-L, despite its typically benign nature, should be carefully monitored. Although most cases of MCN-L do not require immediate surgery, timely surgical intervention may be necessary in cases of rapid growth or persistent symptoms.

Primary Serous Cystadenocarcinoma of the Spleen

Tumours of the spleen are uncommon, and most are metastases from primaries in other organs. Primary splenic malignancies are subdivided into two main groups: lymphoid and non-lymphoid. Primary splenic cystadenocarcinomas are extremely rare, and only reports of the mucinous variant exist. We present the case of a female in her eighth decade of life who was found to have an incidental complex splenic mass with a cystic component, which showed an interval increase in size on serial imaging. After further investigation, including positron emission tomography (PET), endoscopic ultrasound (EUS), and laparoscopy, she successfully underwent distal pancreatectomy, splenectomy, and partial gastrectomy for a suspected locally invasive pancreatic malignancy. Histology and immunohistochemical analyses were consistent with the first recorded case of primary serous cystadenocarcinoma of the spleen in the literature.

Recurrent mucinous cystic neoplasm of the mesentery in a young nullipara mimicking as ovarian carcinoma

INRODUCTION

Mucinous cystic neoplasms are rare tumors. They may originate from either ovaries, pancreas, or other intra-abdominal sites, but rarely from the mesentery.

CASE HISTORY

A 22-year-old nulliparaous woman, who had undergone laparascopic bilateral cystectomy for recurrent ovarian mass, presented with pain in abdomen, backache, and menstrual irregularities. Provisionally diagnosed as ovarian carcinoma, she underwent bilateral salpingo-oophorectomy and sigmoid colectomy. However, the histopathological examination revealed mucinous cystic neoplasm of the mesentery.

DISCUSSION

Thus, complete resection of the cysts with meticulous gross and histopathological examination remains the gold standard to differentiate mucinous cystic neoplasm (MCN) of the mesentery from its mimics, especially malignant counterparts, enabling clinicians to adequately manage such patients. Here, we present a case of recurrent MCN of mesentery (mesocolon), mimicking as ovarian carcinoma confirmed on histopathological examination, in a young adult.

Intralobular distribution of ovarian-like stroma in pancreatic mucinous cystic neoplasms: a discussion on its tumorigenesis

Pancreatic mucinous cystic neoplasm (MCN) has two histological components: tumor epithelia and ovarian-like stroma (OLS). To examine the progression and changes in pancreatic MCNs, we analyzed the distribution, amount, immunohistochemical phenotype, presence of theca cells of OLS, and tumor epithelium in 45 surgically resected MCN cases, comparing them with tumor sizes. The OLS data of female MCN cases were also compared between those who were ≤ 51 years old and those > 51 years old to see the effect of menopause on MCN histology. Non-mucinous type epithelium was present in all low-grade MCNs, but its ratio decreased with tumor size (p < 0.001), suggesting that epithelial mucinous changes are a progression phenomenon. The intralobular distribution of OLS was observed in 28.8% of MCN cases and was related to smaller tumor size (p < 0.0001), suggesting intralobular involvement of early MCNs. The nuclear expression of β-catenin and the cytoplasmic expression of α-smooth muscle actin (SMA) was observed in almost all OLS. OLS tended to be lesser among female cases aged > 51 years than those ≤ 51 years old, however it did not reach statistical significance. This is the first study to show the intralobular distribution of OLS.

Mucinous cystic neoplasm of the liver: A case report

BACKGROUND

Mucinous cystic neoplasm of the liver (MCN-L) is a cyst-forming epithelial neoplasm. The most distinguishing feature is the ovarian-type subepithelial stroma on pathological examination.

CASE SUMMARY

An abdominal ultrasound incidentally revealed a liver tumor in a 32-year-old woman. Physical and laboratory examination results did not reveal any abnormalities. Enhanced abdominal computed tomography (CT) revealed a cystic space measuring 7.2 cm × 5.4 cm in the liver. Subsequent CT showed an increase in tumor size. Thus, we performed surgical resection of the tumor and gallbladder. Postoperative histopathological examination confirmed the diagnosis of MCN-L. At the 6-mo of follow-up, no recurrence was observed on ultrasound or CT.

CONCLUSION

Since preoperative diagnosis of MCN-L is difficult, active surgery is recommended and helpful for the diagnosis and treatment of MCN-L.

Mucinous cystic neoplasm of the liver (MCN-L): a rare presentation and review of the literature

Mucinous cystic neoplasms of the liver (MCN-L, (previously referred to as cystadenomas or cystadenocarcinoma) are rare cystic tumors that occur within the liver parenchyma, or less frequently, in the extrahepatic bile ducts. They are reported to account for <5% of all liver cysts. The differential diagnosis of MCN-L includes intraductal papillary neoplasm of the bile duct (IPNB), intrahepatic cholangiocarcinoma with cystic change, echinococcal cyst, and a simple cyst. Invasive MCNs can only be differentiated from non-invasive MCNs by microscopic evaluation for the presence of ovarian-type stroma. Intraoperative biopsy and frozen section(s) are essential to differentiate MCNs from other cystic liver lesions. The treatment of choice is complete excision and can result in excellent survival with initial correct diagnosis. But its rare presentation and insufficient recognition frequently lead to an incorrect initial or delayed diagnosis or misdiagnosis.

Mesenteric and Retroperitoneal Mucinous Cystic Neoplasms: A Case Series

Aims. Mucinous cystic neoplasms (MCNs) are cystic neoplasms with mucinous epithelium surrounded by ovarian-like stroma. Extraovarian MCN occurring in the liver and pancreas have been well characterized. However, only rare case reports of MCN arising outside of these locations have been reported. MCNs arising in unusual locations should enter the differential diagnosis of mucinous intra-abdominal tumors and must be distinguished from more common mimics. Therefore, we aimed to examine a series of MCNs of the retroperitoneum and mesentery to characterize the clinicopathologic features of this entity. Methods and results. Seven MCNs arising in the abdominal mesentery or retroperitoneum were retrospectively identified. A clinicopathologic, histologic, and immunohistochemical (keratin 7, keratin 19, keratin 20, calretinin, inhibin-α, steroidogenic factor-1 (SF-1), estrogen receptor (ER), progesterone receptor (PR), PAX8, CDX2, and CD10) analysis was performed. All 7 MCNs were from females with a median age of 41 years old and a median size of 8 cm. All cases demonstrated mucinous with or without concomitant non-mucinous epithelium overlying spindle cell ovarian-like stroma. Luteinized cells were noted. The epithelium was positive for keratin 7 and keratin 19 in all 7 cases, while the stroma expressed ER, PR, and SF-1 in all cases stained. Calretinin was focally positive in the stroma of 3 of 7 cases, while inhibin-α was focally expressed in 5 of 6 cases. Conclusions. These results highlight the clinicopathologic, histologic, and immunophenotypic similarities between MCNs of the mesentery, retroperitoneum, pancreas, and liver. Overlapping features suggest a common histogenesis for all MCNs, which could include periductal fetal mesenchyme, aberrant migration of primordial germ cells, or abnormal differentiation or metaplasia of the embryonic coelomic epithelium.

Mucinous cystadenocarcinoma of the spleen - a very rare case of a primary splenic MCN

INTRODUCTION

We present the case of a primary spleen mucinous cystadenocarcinoma. Several cases of this primary tumor of the spleen have been described worldwide so far. These tumors are classified as mucinous cystic neoplasms (MCN) and occur mainly in the ovaries and pancreas. &lt;br/&gt;&lt;br/&gt;Case report: The case concerns a 45-year-old female patient with an accidentally diagnosed splenic tumor with approximately 20 cm in size. Histopathological examinations, following a splenectomy, confirmed the presence of mucinous cystadenocarcinoma.

Usefulness of 18F-fluorodeoxyglucose-positron emission tomography/computed tomography in primary cystadenocarcinoma of the mesentery: a case report

BACKGROUND

Mesenteric cysts have various histological forms, including mesenteric cystadenomas and borderline cystic neoplasms. Primary cystadenocarcinoma of the mesentery is extremely rare; therefore, the clinical and radiological features of this tumor have not been fully elucidated.

CASE PRESENTATION

A 50-year-old Japanese woman had a complaint of a left-sided abdominal distention. Enhanced computed tomography and magnetic resonance imaging revealed a unilocular cystic lesion measuring approximately 10 cm located in the left side of the abdomen. ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography/computed tomography (PET/CT) revealed mottled mild FDG uptake in the cyst wall and intense FDG uptake in several mural nodules. The cystic mass with the descending colon was completely removed. Pathological examination of the specimens revealed various histologic patterns of adenocarcinoma, including mucin production in the mural nodules. We eventually diagnosed a primary cystadenocarcinoma arising from the mesentery of the descending colon.

CONCLUSIONS

Malignancy should be suspected in mesenteric or retroperitoneal cystic tumors with high FDG uptake, and complete resection should be performed with adequate margins.

Large intra-abdominal mucinous cystic adenoma: is it of ovarian or mesenteric origin

A 54-year-old female presented with a six year history of increasing abdominal swelling and discomfort and two months of intermittent constipation and difficulty with micturition. She was referred from the gynecological service having been investigated for a pelvic pathology without any positive findings. Her medical history was otherwise unremarkable. Physical examination revealed a non-tender intra-abdominal mass extending from epigastrium to the pelvis with a smooth surface. A large intra-abdominal multi-loculated cyst, separate from the ovaries, was seen on imaging. At laparotomy, the cystic tumour was discovered to arise from the mesentery of the terminal ileum and was resected en bloc. Histopathology revealed the tumour to be a benign mucinous cystadenoma, possibly of ovarian origin. This report aims to raise awareness of the difficulty of distinguishing ovarian from extra-ovarian mucinous cystadenomas on histopathological examination alone.

Mucinous cystic neoplasms of the liver: presence of biliary communication

A 35-year-old woman was referred for a symptomatic liver mass. Diagnostic workup detected a septated cyst located centrally in the liver measuring 10 × 7 cm. The cyst had gradually increased in size from previous studies with new intrahepatic biliary dilation. Due to concern for malignancy and symptomatic presentation of the patient, a partial central hepatectomy was performed. Pathology revealed a smooth-walled, multiloculated cyst lined with mucinous epithelium and ovarian-type stroma. The diagnosis of low-grade mucinous cystic neoplasm of the liver (MCN-L) was made. Characteristics of MCN-L have not been elucidated due to its rarity.

Early detection of intrahepatic cholangiocarcinoma

Cholangiocarcinoma (CC) is a malignant tumor which arises from the biliary epithelium and most cases represent adenocarcinoma. CC can be classified into intrahepatic CC (ICC), perihilar CC, and distal CC, based on the site of anatomic origin. The incidence of ICC is increasing in both Western and Eastern countries, while that of extrahepatic cholangiocarcinoma remains fairly stable. ICC infiltrates into adjacent nerves and lymphatic vessels, resulting in progressive disease with a poor prognosis; thus, early detection of ICC is critical for achieving better outcomes and providing better patient care. However, it is difficult for clinicians to detect an ICC, especially in its early stage. Different from hepatocellular carcinoma, the lack of surveillance system for the high-risk group of CC does not allow for a reliable screening examination. In this context, for early detection and diagnosis of ICC, radiologists need to know predisposing conditions that can lead to the development of ICC, such as chronic biliary or hepatic inflammation, primary sclerosing cholangitis, congenital biliary diseases, and other conditions. In this article, we discuss and illustrate the radiologic features of ICC with special attention to early disease stages and of predisposing conditions of ICC.

Histo-molecular oncogenesis of pancreatic cancer: From precancerous lesions to invasive ductal adenocarcinoma

Pancreatic cancer is a lethal malignancy, whose precursor lesions are pancreatic intraepithelial neoplasm, intraductal papillary mucinous neoplasm, intraductal tubulopapillary neoplasm, and mucinous cystic neoplasm. To better understand the biology of pancreatic cancer, it is fundamental to know its precursors and to study the mechanisms of carcinogenesis. Each of these precursors displays peculiar histological features, as well as specific molecular alterations. Starting from such pre-invasive lesions, this review aims at summarizing the most important aspects of carcinogenesis of pancreatic cancer, with a specific focus on the recent advances and the future perspectives of the research on this lethal tumor type.

A rare case of giant extra-ovarian mucinous cystadenoma arising from sigmoid mesocolon

An 80-year-old female presented with one month history of acutely worsening abdominal distention and pain, without features of bowel obstruction. A giant intra-abdominal simple cyst, separate from the ovaries, was seen on imaging. Initial haematological and biochemical investigations, including tumour markers, were normal. At laparotomy, the cystic tumour was discovered to arise from the sigmoid mesocolon and was resected en bloc. Histopathology revealed the tumour to be a benign extra-ovarian mucinous cystadenoma, which is a neoplasm of ovarian origin that can arise from extra-ovarian sites, including the mesentery. Extra-ovarian mucinous cystadenoma arising specifically from the mesentery are very rare intra-abdominal neoplasms with malignant potential despite its benign appearance on investigations. This case aims to raise awareness of this condition and to highlight its diagnostic approach and surgical management.

Pathology of Pancreatic Cancer Precursor Lesions

To better understand pancreatic ductal adenocarcinoma (PDAC) and improve its prognosis, it is essential to understand its origins. This article describes the pathology of the 3 well-established pancreatic cancer precursor lesions: pancreatic intraepithelial neoplasia, intraductal papillary mucinous neoplasm, and mucinous cystic neoplasm. Each of these precursor lesions has unique clinical findings, gross and microscopic features, and molecular aberrations. This article focuses on histopathologic diagnostic criteria and reporting guidelines. The genetics of these lesions are briefly discussed. Early detection and adequate treatment of pancreatic cancer precursor lesions has the potential to prevent pancreatic cancer and improve the prognosis of PDAC.

Pathologic Features of Primary and Metastatic Hepatic Malignancies

In the mammalian liver, 60 % of the cellular components are hepatocytes while the remainder (35 %) includes biliary epithelium, Kupffer cells, endothelial cells, fat storing cells and connective tissue cells. Although neoplasms of hepatocytes are the most common, a significant number of both benign and malignant primary liver neoplasms arising from other cell types can develop, such as tumors of bile duct epithelium (Table 1). In addition, the liver is one of the most susceptible sites for metastatic tumors arising from other organs of the body. Not too long ago, liver tumors were left untreated because the liver was considered a complex and mysterious organ inaccessible to surgery. Advances in imaging procedures and surgical techniques over the past 40 years have revolutionized the approaches to the treatment of benign and malignant liver tumors. Subsegmentectomy, segmentectomy, lobectomy, and transplantation are routinely performed for the treatment of primary and metastatic liver tumors with minimal morbidity and mortality. Since accurate diagnosis remains the key to clinical and surgical management, the emphasis of this chapter is on classification, morphological features and differential diagnosis of malignant neoplasms of the liver.

A case of mucinous cystic neoplasm of the liver: a case report

A 71-year-old woman was referred to our institution for further investigation of epigastric pain. The patient had been detected to have a multilocular cyst in the medial segment of the liver measuring 69 mm in diameter at another hospital 2 years ago, and the diameter of the cyst had increased to 90 mm. Although the cyst had gradually increased in size, there was no evidence of mural nodules. As we were concerned about the malignant potential of the lesion, a left hepatic segmentectomy was performed. Pathologically, the cyst was lined by columnar and cuboidal epithelium with low-grade atypia. The epithelium covered an ovarian-like stroma, and the diagnosis was mucinous cystic neoplasm of the liver (MCN-L) with low-grade intraepithelial neoplasia. MCN-L is a rare disease and its characteristics are still poorly understood. MCN-L occurs at a lower frequency as compared to the counterpart of MCN of the pancreas, further investigations are necessary to clarify the biological malignancy of MCN-L.

Serous cystadenocarcinoma of the mesentery in a man: case report and review of literature

In February 2007, a 41-year-old Japanese male was admitted to our hospital with increasing upper abdominal pain. A contrast-enhanced computed tomography (CT) scan of the abdomen demonstrated a well-demarcated, hypodense cystic mass with a thickened wall in the mesocolon. The laboratory results were within normal limits, except for increased carcinoembryonic antigen, carbohydrate antigen 19-9, DUPAN-2 and SPAN-1. The patient was diagnosed as having a mesenteric malignant cyst, and during a laparotomy, a right hemicolectomy with mesenteric cystectomy was performed without rupture in March 2007. In the microscopic findings, there was a well-differentiated adenocarcinoma in the inner surface of the cyst and in the fibrous connective tissue of the hypertrophic cystic wall. The tumor cells were immunohistochemically reactive to cytokeratin (CK) 7, CK18 and CK20. No remnant of the malignancy was detected in the resected margin of the colon, cyst, liver or peritoneum nor was an uptake detected in an 18[F]-fluorodeoxyglucose positron emission tomography/CT examination of other organs. Finally, the malignancy was concluded to be a serous cystadenocarcinoma of the mesentery. Nineteen months after the operation, the patient died from peritonitis carcinomatosa due to a small intestine rupture. This report suggests mesenteric cystadenocarcinomas originating in the ovary, oviduct and intestinal mucosa, but these were ruled out in our patient. In this report, we discuss a case of the malignant transformation of a cyst into adenocarcinoma, which to our knowledge has never been previously reported in a male patient.

A mucinous cystic neoplasm of the mesocolon showing features of malignancy

Mucinous cystic neoplasms are rare tumours of uncertain histogenesis. They arise from the ovaries, pancreas, and other intra-abdominal sites but more unusually from the mesocolon. They can present with abdominal pain, distension, or a palpable mass but are commonly an incidental finding. We describe the case of a 48-year-old woman who was found to have an incidental left pelvic cyst on computed tomography. Subsequent laparoscopic excision and histological analysis demonstrated the cyst to be a borderline malignant mucinous tumour arising from the mesocolon. Mucinous tumours should be considered in the differential diagnosis of all intra-abdominal cysts and treatment should be by surgical complete excision.

Mucinous cystadenoma of the mesocolon, a rare entity frequently presenting with features of malignity: two case reports and review of the literature

PURPOSE

Mucinous cystadenomas are tumors arising mostly from the ovaries and pancreas. They can also arise from the kidneys, lungs, liver and appendix, but are rarely seen in the mesocolon. Recently, they have been included in an updated classification of mesenteric cysts and cystic tumors. The WHO classification (ICD 10) divides them into three subcategories according to their malignant behavior.

METHODS

This report of two cases of mucinous cystadenoma of the mesocolon discusses the diagnostic and therapeutic modalities as well as the pathophysiological pathway(s) of development of these neoplasms.

RESULTS AND CONCLUSION

The diagnosis of mucinous cystadenomas of the mesocolon is challenging due to the absence of specific clinical, biological and radiological features, and is often made during or after laparotomy. Preoperative biopsy is not useful and may even lead to misdiagnosis or peritoneal spillage. Surgery is the only curative treatment, but the modalities of resection are still a subject of debate.

Cystic tumors of the liver: on the problems of diagnostic criteria

We report on three cases of cystic neoplasms of the liver with mucinous epithelium. Case 1 showed a low-grade cystic neoplasm with ovarian-like stroma (OS). Case 2 showed a low-grade cystic neoplasm without OS, and case 3 showed a high-grade cystic neoplasm without OS. In all three cases, bile duct communication (BDC) was absent. Currently, pancreatic mucinous cystic neoplasm (MCN) and intraductal papillary mucinous neoplasm of the pancreas (IPMN) are clearly distinguishable. However, MCN of the liver and intraductal papillary neoplasm of the bile duct (IPN-B) are not as easily distinguished. According to the latest WHO classification (2010), these conditions are classed as typical MCN of the liver, MCNs of the liver without OS, or IPN-Bs without BDC. The clinicopathological differences between MCN without OS and IPN-B without BDC are controversial. We present three cases describing these presentations and discuss the difficulties related to the diagnostic criteria used to distinguish between MCN of the liver and IPN-B.

Management of mucinous cystic neoplasms of the pancreas

The purpose of this study was to investigate the actual management of mucinous cystic neoplasm (MCN) of the pancreas. A systematic review was performed in December 2009 by consulting PubMed MEDLINE for publications and matching the key words “pancreatic mucinous cystic neoplasm”, “pancreatic mucinous cystic tumour”, “pancreatic mucinous cystic mass”, “pancreatic cyst”, and “pancreatic cystic neoplasm” to identify English language articles describing the diagnosis and treatment of the mucinous cystic neoplasm of the pancreas. In total, 16 322 references ranging from January 1969 to December 2009 were analysed and 77 articles were identified. No articles published before 1996 were selected because MCNs were not previously considered to be a completely autonomous disease. Definition, epidemiology, anatomopathological findings, clinical presentation, preoperative evaluation, treatment and prognosis were reviewed. MCNs are pancreatic mucin-producing cysts with a distinctive ovarian-type stroma localized in the body-tail of the gland and occurring in middle-aged females. The majority of MCNs are slow growing and asymptomatic. The prevalence of invasive carcinoma varies between 6% and 55%. Preoperative diagnosis depends on a combination of clinical features, tumor markers, computed tomography (CT), magnetic resonance imaging, endoscopic ultrasound with cyst fluid analysis, and positron emission tomography-CT. Surgery is indicated for all MCNs.

Mucinous cystic neoplasms of the mesentery: a case report and review of the literature

Background

Mucinous cystic neoplasms arise in the ovary and various extra-ovarian sites. While their pathogenesis remains conjectural, their similarities suggest a common pathway of development. There have been rare reports involving the mesentery as a primary tumour site.

Case presentation

A cystic mass of uncertain origin was demonstrated radiologically in a 22 year old female with chronic abdominal pain. At laparotomy, the mass was fixed within the colonic mesentery. Histology demonstrated a benign mucinous cystadenoma.

Methods and results

We review the literature on mucinous cystic neoplasms of the mesentery and report on the pathogenesis, biologic behavior, diagnosis and treatment of similar extra-ovarian tumors. We propose an updated classification of mesenteric cysts and cystic tumors.

Conclusion

Mucinous cystic neoplasms of the mesentery present almost exclusively in women and must be considered in the differential diagnosis of mesenteric tumors. Only full histological examination of a mucinous cystic neoplasm can exclude a borderline or malignant component. An updated classification of mesenteric cysts and cystic tumors is proposed.

Mucinous cystic neoplasm of the pancreas is not an aggressive entity: lessons from 163 resected patients

OBJECTIVE

Mucinous cystic neoplasms (MCNs) of the pancreas have often been confused with intraductal papillary mucinous neoplasms. We evaluated the clinicopathologic characteristics, prevalence of cancer, and prognosis of a large series of well-characterized MCNs in 2 tertiary centers.

METHODS

Analysis of 163 patients with resected MCNs, defined by the presence of ovarian stroma and lack of communication with the main pancreatic duct.

RESULTS

MCNs were seen mostly in women (95%) and in the distal pancreas (97%); 25% were incidentally discovered. Symptomatic patients typically had mild abdominal pain, but 9% presented with acute pancreatitis. One hundred eighteen patients (72%) had adenoma, 17 (10.5%) borderline tumors, 9 (5.5%) in situ carcinoma, and 19 (12%) invasive carcinoma. Patients with invasive carcinoma were significantly older than those with noninvasive neoplasms (55 vs. 44 years, P = 0.01). Findings associated with malignancy were presence of nodules (P = 0.0001) and diameter > or =60 mm (P = 0.0001). All neoplasms with cancer were either > or =40 mm in size or had nodules. There was no operative mortality and postoperative morbidity was 49%. Median follow-up was 57 months (range, 4-233); only patients with invasive carcinoma had recurrence. The 5-year disease-specific survival for noninvasive MCNs was 100%, and for those with invasive cancer, 57%.

CONCLUSIONS

This series, the largest with MCNs defined by ovarian stroma, shows a prevalence of cancer of only 17.5%. Patients with invasive carcinoma are older, suggesting progression from adenoma to carcinoma. Although resection should be considered for all cases, in low-risk MCNs (< or =4 cm/no nodules), nonradical resections are appropriate.

Abdominal mucinous cystic neoplasm in a male child

Mucinous cystic neoplasms (MCNs) make up a morphologic family of similar appearing tumors arising in the ovary and various extraovarian sites, including the pancreas, hepatobiliary tract, paratesticular soft tissues, and mesentery. Other than the uncommon mucinous cystadenoma of the ovary presenting in adolescence, MCNs are rarely seen by the pediatric pathologist. The present case is a 5-year-old boy with an abdominal mass appearing to arise in the mesentery of the small intestine. Because of its unresectability, a generous biopsy was performed and disclosed a MCN with focal complex papillary architecture in the absence of appreciable cytologic atypia or invasion into the wall. Like other MCNs, this tumor had an inhibin-positive, ovarian-like stroma that was nonreactive for estrogen and progesterone receptors. Only 1 other case of a mesenteric MCN has been reported to date in a child and none in a male. The MCN of the mesentery joins other, somewhat more common cystic lesions of the omentum and mesentery presenting in childhood.

Cystic neoplasms of the exocrine pancreas

The increasing use of radiological imaging has led to greater detection of small and asymptomatic cystic lesions of the pancreas. Most are resectable, but not all are neoplastic. This review provides an update on the histopathology, immunohistochemistry, molecular biology, pathogenesis and management of cystic neoplasms of the exocrine pancreas. These include the serous, the mucinous cystic, the intraductal papillary mucinous and the solid pseudopapillary neoplasms. Recently reported variants are described and very rare cystic variants of other pancreatic epithelial and mesenchymal neoplasms are briefly mentioned.