The Cancer Diaspora: A Rare Case of Pseudomyxoma Peritonei of Appendiceal Origin.

Pseudomyxoma peritonei (PMP) is a rare clinical entity characterized by widespread mucinous implants in the peritoneal cavity. Commonly seen in females in their 50s, PMP typically originates from ruptured appendiceal mucoceles that find refuge in the peritoneal space. Rarely, PMP may originate from the ovary, stomach, colon, or pancreas. Pseudomyxoma peritonei of colorectal origin is more malignant and has a lower survival rate. We report a case of a 59-year-old Hispanic woman with PMP who presented to the emergency room with a 3-month history of progressive abdominal distention. Pseudomyxoma peritonei was confirmed by computed tomography (CT) scan of the abdomen and pelvis and histopathology, and the patient underwent partial cytoreductive surgery. Given her Eastern Cooperative Oncology Group (ECOG) performance status of 1 despite extensive carcinomatosis, our patient may benefit from hyperthermic intraperitoneal chemotherapy (HIPEC) in the future.

Low-Grade Pseudomyxoma Peritonei Behaving as a High-Grade Disease: A Case Series and Literature Review.

Patients with low-grade appendiceal mucinous carcinomas (LAMNs) treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have a favorable prognosis. However, a subgroup of patients presents a clinically aggressive course with disease progression despite receiving treatment. The purpose of this study is to report the experience of clinically aggressive LAMN patients treated by the same team, and to present a review of the literature. The cases of four patients with clinically aggressive LAMNs were reviewed. Clinical and histopathological characteristics were re-examined. Recurrences and the time of recurrence, as well as the survival time, were recorded. These patients were four men with clinically aggressive LAMNs treated with CRS plus HIPEC. One of them underwent CC-0 surgery, two underwent CC-1 surgery, and one underwent CC-3 surgery. All patients received systemic chemotherapy after surgery. Recurrence was recorded in three of the patients within 4-23 months after the initial treatment. Two of the patients underwent secondary CRS. Three patients died of disease recurrence within 13-23 months, and one is alive with a disease relapse at 49 months after his initial surgery. LAMNs were identified in both the initial specimens and the specimens obtained during reoperation. The prognosis of LAMN patients treated with CRS plus HIPEC is favorable. A small number of patients present a clinically aggressive course that is unresponsive to any treatment. Molecular and genetic studies are required to identify this group of LAMN patients who have an unfavorable prognosis.

Rare occurrence of pseudomyxoma peritonei (PMP) syndrome arising from a malignant transformed ovarian primary mature cystic teratoma treated by cytoreductive surgery and HIPEC: a case report.

BACKGROUND: Pseudomyxoma peritonei (PMP) syndrome is a disease process that typically occurs from ruptured appendiceal mucocele neoplasms. PMP syndrome arising from malignant transformation of an ovarian primary mature cystic teratoma (MCT) is a pathogenesis rarely encountered. CASE PRESENTATION: Herein, we report a 28-year-old patient evaluated and treated for a right ovarian mass and large volume symptomatic abdominopelvic mucinous ascites. Molecular profiling and genetic analysis revealed mutations in ATM, GNAS, and KRAS proteins while IHC demonstrated gastrointestinal-specific staining for CK20, CDX2, CK7, and SATB2. Peritoneal cytology showed paucicellular mucin. Diffuse peritoneal adenomucinosis (DPAM) variant of PMP arising from a ruptured ovarian primary MCT after malignant transformation to a low-grade appendiceal-like mucinous neoplasm was ultimately confirmed. Treatment included staged therapeutic tumor debulking and right salpingo-oophorectomy followed by cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC). CONCLUSIONS: Our report builds upon the existing literature supporting this aggressive treatment option reserved for advanced abdominal malignancies utilized in this patient with a rare clinical entity.

Role of Epithelial-Mesenchymal Plasticity in Pseudomyxoma Peritonei: Implications for Locoregional Treatments.

The mechanisms by which neoplastic cells disseminate from the primary tumor to metastatic sites, so-called metastatic organotropism, remain poorly understood. Epithelial-mesenchymal transition (EMT) plays a role in cancer development and progression by converting static epithelial cells into the migratory and microenvironment-interacting mesenchymal cells, and by the modulation of chemoresistance and stemness of tumor cells. Several findings highlight that pathways involved in EMT and its reverse process (mesenchymal-epithelial transition, MET), now collectively called epithelial-mesenchymal plasticity (EMP), play a role in peritoneal metastases. So far, the relevance of factors linked to EMP in a unique peritoneal malignancy such as pseudomyxoma peritonei (PMP) has not been fully elucidated. In this review, we focus on the role of epithelial-mesenchymal dynamics in the metastatic process involving mucinous neoplastic dissemination in the peritoneum. In particular, we discuss the role of expression profiles and phenotypic transitions found in PMP in light of the recent concept of EMP. A better understanding of EMP-associated mechanisms driving peritoneal metastasis will help to provide a more targeted approach for PMP patients selected for locoregional interventions involving cytoreductive surgery and hyperthermic intraperitoneal chemotherapy.

Macroscopic and microscopic characteristics of low grade appendiceal mucinous neoplasms (LAMN) on appendectomy specimens and correlations with pseudomyxoma peritonei development risk.

Low grade appendiceal mucinous neoplasm (LAMN) is the primary source of pseudomyxoma peritonei (PMP). PMP may develop after seemingly complete resection of primary tumor by appendectomy, which is unpredictable due to lack of reliable prognostic indicators. We retrospectively reviewed 154 surgically resected LAMNs to explore if any of the macroscopic and microscopic characteristics may be associated with increasing risk of PMP development. Our major findings include: (1) As compared to those without PMP, the cases that developed PMP were more frequent to have (a) smaller luminal diameter (<1 cm) and thicker wall, separate mucin aggregations, and microscopic perforation/rupture, all suggestive of luminal mucin leakage; (b) microscopic acellular mucin presenting on serosal surface and not being confined to mucosa; and (c) neoplastic epithelium dissecting outward beyond mucosa, however, with similar frequency of neoplastic cells being present in muscularis propria. (2) Involvement of neoplastic cells or/and acellular mucin at surgical margin did not necessarily lead to tumor recurrence or subsequent PMP, and clear margin did not absolutely prevent PMP development. (3) Coexisting diverticulum, resulted from neoplastic or non-neoplastic mucosa being herniated through muscle-lacking vascular hiatus of appendiceal wall, was seen in a quarter of LAMN cases, regardless of PMP. The diverticular portion of tumor involvement was often the weakest point where rupture occurred. In conclusion, proper evaluation of surgical specimens with search for mucin and neoplastic cells on serosa and for microscopic perforation, which are of prognostic significance, should be emphasized.

Clinicopathologic Features of Low-grade Appendiceal Mucinous Neoplasm: A Single-institution Experience of 117 Cases.

Low-grade appendiceal mucinous neoplasm (LAMN) is an enigmatic tumor that lacks the capacity for classic invasion but can dissect through the appendiceal wall, causing pseudomyxoma peritonei (PMP). Most large studies of the histologic spectrum of LAMN and its rate of associated PMP include cases submitted from outside institutions, potentially skewing their findings. We identified 117 cases of LAMN at our institution. Hematoxylin and eosin-stained slides from each were reviewed, and clinical and pathologic parameters were noted. The patients were 76 females and 41 males, with a mean age of 60 years. Presenting symptoms were available for 113 patients; the majority (56%) were symptomatic, typically with abdominal pain. Ninety-one tumors (78%) were grossly dilated, and the entire appendix was submitted in 88 (75%) cases. Median lesion size was 5.5 cm. Ninety-two cases (79%) demonstrated epithelial denudation; these were often markedly dilated and contained intraluminal or mural microcalcifications. Thirty-two (27%) had a mucosal Schwann cell proliferation. On the basis of the American Joint Committee on Staging eighth edition cancer staging manual, of 117 cases, 66% were staged as pTis, 9% as pT3, 24% as pT4a, and 2% as pT4b. Ten cases (9%) were associated with histopathologic evidence of disseminated PMP. Only 1 patient died of disease, while 3 were alive with disease at last follow-up. Previous LAMN studies have utilized both departmental and extradepartmental material; our single-institution review demonstrated lower rates of PMP than some prior studies. Some LAMNs may be markedly dilated with extensive denudation, making the diagnosis difficult to confirm microscopically and ultimately requiring submission of the entire appendix for histologic evaluation.

Primary low-grade mucinous adenocarcinoma spleen resulting in Pseudomyxoma peritonei: A case report.

A 61-year-old man presented with complaints of abdominal pain, loss of weight, and splenomegaly since past 6 months. On computed tomography, the spleen was totally replaced by multiloculated cysts and splenectomy was performed. Pathological examination revealed a low-grade mucinous adenocarcinoma. Postoperative PET scan was negative, and in the absence of a primary tumor elsewhere, we considered this tumor to be primary in the spleen, and it was presumed that the tumor arose from invaginated capsular mesothelium of the spleen.

[Pseudomyxoma peritonei (PMP) secondary to mucinous carcinoma of the ovary: a case study]. / Pseudomyxome péritonéal secondaire à une tumeur mucineuse de l'ovaire: à propos d'un cas.

Pseudomyxoma peritonei (PMP), also referred to as gelatinous ascites, is a rare disorder, described for the first time by R. Wyerth in 1884. It is characterized by diffuse peritoneal involvement, composed of mucinous ascites and multifocal mucinous epithelial implants. This disease mainly affects women. Its incidence is estimated at 2 cases per one million inhabitants. Pseudomyxoma peritonei can be asymptomatic, discovered during a laparotomy. The most common symptom is abdominal distension associated with diffuse abdominal pain. Abdominal CT scan is the most specific diagnostic tool. It shows pathognomonic signs of gelatinous ascites. Mucinous neoplasms of the appendix are the most frequent cause of pseudomyxoma peritonei accounting for 90% of cases. Pseudomyxoma peritonei of ovarian origin is very rare. There are essentially two types of treatment: multiple debulking surgery and cytoreductive surgery with perioperative intraperitoneal chemotherapy consisting of hyperthermic intraperitoneal chemotherapy with or without immediate postoperative intraperitoneal chemotherapy. We report a case of pseudomyxoma peritonei secondary to mucinous carcinoma of the left ovary.

Ruptured primary mucinous cystadenoma of spleen leading to mucinous ascites.

Mucinous cystadenoma are rare benign mucin-producing tumours. Primary mucinous neoplasms most commonly involve ovary, pancreas or appendix. They may rupture to produce mucous ascites/pseudomyxoma peritonei. We are describing a 51-year-old man who presented to us with symptomatic gallstone disease but during preoperative ultrasound was found to have cystic lesions in spleen with free fluid in the abdomen. Splenectomy and drainage of mucin were done. Histopathology was done and a final diagnosis of primary mucinous cystadenoma of spleen with mucinous ascites was made.

Pseudomixoma peritonei associated with appendiceal cistoadenoma rupture: case report.

Appendiceal mucocele represents specimen finding in 0.2-0.3% out of appendectomies. The rupture or perforation in peritoneal cavity might cause pseudomixoma peritonei (PMP), with multiple mucinous deposits in the abdominal cavity. We report a case of PMP caused by a perforated appendiceal cistoadeonoma.

Factors influencing long-term survival after cytoreductive surgery and hyperthermic intraperitoneal chemotherapy for pseudomyxoma peritonei originating from appendiceal neoplasms.

Background: Pseudomyxoma peritonei (PMP) is a rare disease, most commonly of appendiceal origin. Treatment consists of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC). The aim of this study was to identify prognostic factors for recurrence and survival. Methods: This was an observational study using a prospectively designed database containing consecutive patients with PMP originating from the appendix, undergoing CRS-HIPEC at a tertiary referral centre between 1996 and 2015. Histopathological slides were reassessed. Cox regression was used for multivariable analyses. Results: Of 225 patients identified, 36 (16·0 per cent) were diagnosed with acellular mucin, 149 (66·2 per cent) had disseminated peritoneal adenomucinosis (DPAM) and 40 (17·8 per cent) had peritoneal mucinous carcinomatosis (PMCA). The 5-year overall survival (OS) rates were 93, 69·8 and 55 per cent respectively. Recurrence was observed in 120 patients (53·3 per cent), 39 of whom (17·3 per cent) were treated with a second CRS-HIPEC procedure. Factors independently associated with poor disease-free survival were six or seven affected regions (hazard ratio (HR) 6·01, 95 per cent c.i. 2·04 to 17·73), incomplete cytoreduction (R2a resection: HR 1·67, 1·05 to 2·65; R2b resection: HR 2·00, 1·07 to 3·73), and more than threefold raised carcinoembryonic antigen (CEA) and/or carbohydrate antigen (CA) 19-9 level (HR 2·31, 1·30 to 4·11). Factors independently associated with poorer OS were male sex (HR 1·74, 1·09 to 2·77), incomplete cytoreduction (R2a resection: HR 1·87, 1·14 to 3·08; R2b resection: HR 2·28, 1·19 to 4·34), and more than threefold raised CEA and/or CA19-9 level (HR 2·89, 1·36 to 6·16). Conclusion: CEA and CA19-9 levels raised more than threefold above the upper limit identify patients with PMP of appendiceal origin and poorer survival.

Pseudomyxoma peritonei induced by low-grade appendiceal mucinous neoplasm accompanied by rectal cancer: a case report and literature review.

BACKGROUND: Pseudomyxoma peritonei (PMP) is a disease involving the peritoneum characterized by the production of large quantities of mucinous ascites. PMP has a low incidence, is difficult to diagnose, and has a guarded prognosis. PMP induced by low-grade appendiceal mucinous neoplasm is extremely rare, and PMP accompanied by rectal cancer is even rarer. CASE PRESENTATION: We present a unique case of a 70-year-old male with PMP induced by low-grade appendiceal mucinous neoplasm accompanied by rectal cancer. The patient's clinical, surgical, and histologic data were reviewed. The patient had persistent distended abdominal pain without radiating lower back pain, abdominal distension for 1 month, and no exhaustion or defecation for 4 days. A transabdominal ultrasound-guided biopsy was performed on the first day. The patient received an emergency exploratory laparotomy because of increased abdominal pressure. We performed cytoreductive surgery, enterolysis, intestinal decompression, special tumour treatment and radical resection of rectal carcinoma. The postoperative course was uneventful. The postoperative histological diagnoses were PMP, low-grade appendiceal mucinous neoplasm and rectal medium differentiated adenocarcinoma. At the 1-year follow-up visit, no tumour recurrence was observed by computed tomography (CT). We also performed a literature review. CONCLUSIONS: We should be aware that PMP can rarely be accompanied by rectal cancer, which represents an easily missed diagnosis and increases the difficulty of diagnosis and treatment. Additionally, there are some typical characteristics of PMP with respect to diagnosis and treatment.

Pseudomyxoma Peritonei After a Total Pancreatectomy for Intraductal Papillary Mucinous Neoplasm With Colloid Carcinoma in Lynch Syndrome.

We report a case of pseudomyxoma peritonei (PMP) arising in a 62-year-old male patient with Lynch syndrome (LS). The patient's medical history included an adenocarcinoma of the colon for which a right hemicolectomy was performed and a pancreatectomy due to an intraductal papillary mucinous neoplasm (IPMN) with invasive colloid carcinoma. It was considered that the PMP could be a metastasis of the earlier colonic or pancreatic carcinoma. The pancreatic carcinoma, colon carcinoma, and PMP tissues were examined, and immunohistochemical and molecular analyses were performed to determine the PMP origin. Histopathologic examination revealed morphological similarities with the pancreatic colloid carcinoma, and further immunohistochemical and molecular analyses, including a shared GNAS mutation, confirmed the pancreatic origin of the PMP. In conclusion, this is a unique case of a patient with LS presenting with PMP originating from an IPMN with invasive colloid carcinoma, several years after pancreatectomy. The present case has important diagnostic implications. The IPMN should be considered as a rare extracolonic manifestation of LS, and pancreatic carcinoma origin should be considered in patients presenting with PMP. This case report highlights the added value of molecular diagnostics in daily pathology practice.

Pseudomyxoma peritonei: A case report and review of the literature / Pseudomixoma peritoneal. A propósito de un caso. Revisión bibliográfica

Objective: We present the case of a patient incidentally diagnosed with a pelvic mass next to the bladder. After surgical excision, definitive diagnosis was pseudomyxoma peritonei. We provide a concise review of the literature of this pathology. Methods: A 55 year-old male patient, was found to have, in annual routine ultrasound, a pelvic retrovesical mass. CT guided needle aspirate showed a tumor with myxoid changes and low aggressive cytology. Surgical excision was performed. Results: The excised mass contained the cecal appendix and ileal serosa. Pathology report was: mucinous cystadenoma of the appendix and pseudomyxoma peritonei. Conclusions: PMP is a local-regional disease within the abdomen, characterized by a mucinous tumor (mucocele) that produces a progressive amount of mucinous ascites, which eventually blows-out, and tumor cells are spread through the peritoneal cavity. Treatment options differ significantly, depending the stage of the disease (AU)

Objetivo: Presentamos el caso de un paciente diagnosticado incidentalmente de una masa pélvica lateral a la vejiga. Después de realizarse cirugía de extracción de la masa, el diagnóstico fue de pseudomixoma peritoneal (PMP). Métodos: Un paciente varón de 55 años de edad, en ecografía rutinaria presenta una masa pélvica retrovesical. Punción y aspiración guiada por TAC mostró un tumor con cambios mixoides y citología de baja agresividad. Se realzó cirugía y extracción de la masa. Resultados: La pieza quirúrgica contenía además el apéndice cecal y serosa ileal. El reporte de patología fue: cistoadenoma mucinoso del apéndice y PMP. Conclusiones: PMP es una enfermedad loco-regional del abdomen, caracterizada por un tumor mucinoso (mucocele) que produce una cantidad progresiva de ascitis mucinosa, que eventualmente revienta, y las células malignas son esparcidas en la cavidad peritoneal. Las opciones de tratamiento difieren significativamente según el estado de la enfermedad (AU)

Pseudomyxoma Peritonei as a First Manifestation of KRAS-Mutated Urachal Mucinous Cystadenocarcinoma of the Bladder: A Case Report.

Only 28 cases of pseudomyxoma peritonei (PMP) arising from urachal neoplasms have been reported. We report one example of this extremely rare disease with KRAS mutational status in its spectrum of pathology. A 45-year-old woman presented with urachal frankly invasive mucinous cystadenocarcinoma confined to the dome of the bladder, which clinically manifested as PMP and was not detected at the first surgery. The primary tumour was revealed 6 months later because of its recurrence as PMP. Microscopic investigation revealed tubular adenoma and cystadenocarcinoma communicating with the bladder lumen and transitioning from the urachal urothelium to the mucinous epithelium. A urachal remnant was identified near the neoplasm. On immunohistochemistry, the tumour proved positive for CK7, CK20, CEA, and CDX2. Staining for ß-catenin revealed expression in both the cytoplasm and cell membrane. Mismatch repair protein expression was normal. Somatic KRAS-mutation (G12V) was revealed in tubular adenoma, cystadenocarcinoma, and mucinous carcinoma peritonei and may play an oncogenic role in the malignant transformation of urachal mucosa and the development of PMP.

Pseudomyxoma peritonei diagnosed 19 years after appendicectomy.

Pseudomyxoma peritonei (PMP) is an uncommon clinical finding describing the intraperitoneal accumulation of abundant mucinous, jelly-like material. This entity may represent a spectrum of diseases ranging from mucinous ascites, commonly associated with ruptured epithelial tumours of the appendix, to frank mucinous carcinomatosis. In cases of appendiceal origin, the patient may present with signs and symptoms of acute appendicitis, and thus careful diagnosis must be made in order to correctly and appropriately guide management. This may include a combination of surgical debulking with or without intraperitoneal or systemic chemotherapy. We present a 52-year-old woman with a 4-month history of abdominal pain and distension with a previous appendicectomy 19 years earlier. Radiological and pathological investigations diagnosed a probable PMP secondary to ruptured appendicitis many years ago. We describe her unique case, with emphasis on length of time to diagnosis and clinical management by surgical cytoreduction alone.

Mucocoele and mucinous tumours of the appendix: A review of the literature.

INTRODUCTION: Mucocoele of the appendix is rarely encountered but consultant general surgical and trainees must be aware of it as a differential diagnosis, due to the nuances associated with its management. We aimed to provide a comprehensive review of the current literature concerning this rare surgical pathology. METHODS: Search terms "appendi*", "tumour", "malignancy", "mucino*" and "cystadenoma" were used in combination to identify papers from PubMed. Abstracts and full text were manually reviewed to identify suitable papers. RESULTS: Full search results included 311 articles. Review of titles and abstracts led to further full text review of 46 articles. Of these 30 were selected for inclusion based on relevance, adequate sample size and recent publication date. DISCUSSION: Mucocoele of the appendix describes dilatation with associated luminal mucin and can result from benign and malignant processes. It contributes 0.2-0.7% of all appendiceal pathologies. The most common presenting symptoms are abdominal pain and a palpable mass in the right iliac fossa. Computed tomography of the abdomen and pelvis is key in facilitating diagnosis, although CEA and CA19-9 also have a role. The major complication of malignant causes of mucocoele is progression to pseudomyxoma peritonei. Treatment is surgical with or without chemotherapy depending on the underlying cause. Prognosis depends on aetiology. CONCLUSION: Mucocoele of the appendix is a rare diagnosis. However, given the possibility of neoplastic peritoneal dissemination, it should be considered as a diagnosis, especially in older females with non-specific symptoms similar to appendicitis.