Primary retroperitoneal tumor: mucinous cystoadenocarcinoma.

Primary retroperitoneal mucinous cystadenocarcinomas (PRMCs) are extremely rare tumors with limited understanding of their pathogenesis and biological behavior. We describe a case of a 50-year-old female patient who underwent surgical treatment. The patient had a history of previous surgeries for mesenteric mucinous cystadenoma, without evidence of recurrence. During routine abdominal ultrasound a new tumor was found. An abdomen magnetic resonance imaging was done and confirmed the presence of a cystic lesion in the right iliac fossa. After discussion in multidisciplinary committee, surgical complete resection of the tumor, along with bilateral adnexectomy, was performed successfully. Histopathological examination revealed a mucinous adenocarcinoma adjacent to a mucinous cystadenoma. Immunohistochemical analysis supported the diagnosis of a primary retroperitoneal lesion. The patient had an uneventful recovery and has remained disease-free during the two-year postoperative follow-up. PRMCs are challenging to diagnose preoperatively due to nonspecific symptoms. Surgical excision is the mainstay of treatment. The long-term prognosis and optimal therapeutic strategies require further investigation.

Los cistoadenocarcinomas mucinosos primarios retroperitoneales (CMPR) son tumores extremadamente raros con una comprensión limitada de su patogénesis y comportamiento biológico. Describimos el caso de una mujer de 50 años sometida a tratamiento quirúrgico. La paciente tenía antecedentes de cirugías previas por cistodenoma mucinoso mesentérico, sin evidencia de recurrencia. Durante una ecografía abdominal de rutina se encontró un nuevo tumor. Se realizó una resonancia magnética abdomen que confirmó la presencia de una lesión quística en la fosa ilíaca derecha. Luego de discutir el caso en el comité multidisciplinario, se realizó con éxito la resección quirúrgica completa del tumor, junto con la anexectomía bilateral. El examen histopatológico reveló un adenocarcinoma mucinoso adyacente a un cistodenoma mucinoso. El análisis inmunohistoquímico apoyó el diagnóstico de lesión primaria retroperitoneal. La paciente tuvo una buena recuperación y permaneció libre de enfermedad durante dos años de seguimiento postoperatorio. Los CMPR son difíciles de diagnosticar debido a que presentan síntomas inespecíficos. La escisión quirúrgica es la base del tratamiento. El pronóstico a largo plazo y las estrategias terapéuticas óptimas requieren más investigación.

Mucinous cystadenoma and carcinoid tumor arising from an ovarian mature cystic teratoma in a 60 year-old patient: a case report.

BACKGROUND: Mature cystic teratomas (MCT) of the ovary are benign ovarian germ cell neoplasms. Malignant transformation is possible but rare and ovarian carcinoid tumors in MCT are among the most extremely rare subtypes. CASE PRESENTATION: We report a case of a 60-year-old Iranian woman suffering from postmenopausal bleeding and hypogastric pain for the last 40 days. An adnexal mass was detected during the physical examination. Ultrasound imaging showed a (55 × 58) mm mass in the left ovary. Total abdominal hysterectomy, bilateral salpingooophorectomy and comprehensive staging surgery were performed for the patient. Intraoperative frozen section of the left ovarian mass was indicative of a malignant tumor. She was diagnosed with a carcinoid tumor with benign mucinous cystadenoma arising on MCT of the ovary, confirmed in the histopathology and immunohistochemistry examination. The tumor was classified as low grade and no chemotherapy cycles were considered. The patient was followed up long-term and no recurrence was observed during 14 months of examinations. CONCLUSION: Ovarian carcinoids arising from MCT are rare neuroendocrine neoplasms, and proper diagnosis of these tumors requires careful histopathology evaluation and appropriate examination. Therefore, it is necessary to consider these tumors as a possible differential diagnosis and evaluate them in individuals (especially postmenopausal women) who have abdominal pain or abnormal bleeding and a palpable mass.

The frequency and prognostic role of P53 and P16 immunoexpression in primary ovarian mucinous tumors.

BACKGROUND: Primary ovarian mucinous tumors are uncommon. Factors leading to invasive progression and metastatic disease have not been fully delineated yet. The aim of this study is to determine the rates of p53 and p16 immunoexpressions in primary ovarian mucinous tumors, to investigate their relationship with clinicopathologic factors and their impact on prognosis and survival. METHODS: Seventy-eight primary ovarian mucinous tumors (30 mucinous cystadenomas, 30 mucinous borderline tumors (MBOT), 18 mucinous carcinomas (MOC)) were evaluated immunohistochemically with p53 and p16 staining. The demographic, clinicopathological data, and postoperative follow-up findings of the patients were analyzed. RESULTS: Mutation-type p53 staining was present in 1/30 (3.3 %) cystadenoma, 10/30 (33.3 %) MBOT and 9/18 (50 %) MOC (p = 0.001). p16 overexpression was detected in 3/30 (10.0 %) MBOT and 5/18 (27.8 %) MOC, but not in any cystadenoma (p = 0.04). The frequency of mutation-type p53 staining in MBOTs with microinvasion was higher (71.4 %) than in those without (28.6 %, p = 0.026). The frequencies of p16 or p53 mutations were similar in MBOTs with and without intraepithelial carcinoma, or mural nodule (p > 0.05). In MOCs with ovarian surface involvement, mutation-type p53 staining was detected in 66.7 % (6/9) and p16 overexpression in 55.6 % (5/9) of the cases. A significant difference was found between MOCs with or without ovarian surface involvement regarding the frequency of p16 overexpression (p = 0.029). Any relationship was not detected between survival and p53 and p16 expression in MOCs (p > 0.05). CONCLUSION: p53 and p16 mutation rates were higher in MOCs compared to mucinous cystadenomas and MBOTs and suggest a relevant role in the development of primary ovarian mucinous carcinoma, however further studies are needed in this regard.

Primary mucinous tumors of the renal pelvis: Clinical, histopathological, and molecular analysis of three cases.

Primary mucinous tumors of the renal pelvis are extremely rare and pose challenges in terms of diagnosis and treatment. This study reviewed the clinical and pathological characteristics of mucinous tumors of the renal pelvis, including mucinous cystadenocarcinomas and mucinous cystadenomas. Immunohistochemical analysis was conducted in three cases, along with KRAS gene detection using the Amplification Refractory Mutation System (ARMS) method. The results revealed mucinous epithelium with acellular mucinous pools in all cases, and acellular mucinous pools were observed in the renal parenchyma and perirenal fat capsules. All tumors expressed CK20 and CDX2, and one case showed KRAS gene mutation. The study suggests that mucinous cystadenomas of the renal pelvis may exhibit borderline biological behaviors. This study is the first to report a KRAS gene mutation in a mucinous cystadenoma of the renal pelvis, offering valuable insights into the diagnosis and treatment of this rare condition.

Mucinous cystadenoma and benign mesonephric-like proliferation in the ovary - Further evidence for clonal relationship.

Mesonephric-like adenocarcinomas rarely occur in the uterus and the ovary. Benign mesonephric-like (ML) proliferations and hyperplasia have been described solely within the ovary. Pathogenetic data are very limited. We report a case with microscopic focus of benign ML-proliferation in association with mucinous cystadenoma in the ovary. The immunophenotype was distinct (mucinous tumor: focal weak nuclear positivity for PAX-8, CK 7, patchy cytoplasmic positivity for p16 and negativity for estrogen receptor, CD 10, TTF-1, p53 wildtype; mesonephric component: diffusely positive for PAX-8, CK 7, luminal CD 10, TTF-1, focal staining for estrogen receptor, patchy cytoplasmic for p16, p53 wildtype). On NGS-analysis there was clonal mutation of KRAS p.G12C. The data provide additional evidence for the concept of transdifferentiation (Müllerian tissue representing Wolffian/mesonephric features on histology and immunostaining) within the pathogenesis of mesonephric proliferation of the female genital tract and demonstrate the clonal relationship between these distinct morphologic components.

Full-term pregnancy with retroperitoneal giant mucinous cyst: A case report and literature review.

RATIONALE: Retroperitoneal benign cysts during pregnancy are extremely rare and often remain asymptomatic until they attain a very large size. Diagnosis typically relies on a pathological tissue biopsy. The decision to pursue 1-step or 2-step surgical treatment should be tailored to each individual case rather than generalized. PATIENT CONCERNS: This case report presents the unique scenario of a pregnant woman with a confirmed pregnancy complicated by a large retroperitoneal cyst. The patient had a retroperitoneal cyst during her initial pregnancy, which went undetected during the first cesarean section. However, it was identified during her second pregnancy by which time it had grown to 13.0 cm × 15.0 cm × 25.0 cm, and extended from the liver margin to right ovarian pelvic infundibulopelvic ligament. Consequently, it was removed smoothly during her second cesarean section. DIAGNOSES: Postoperative pathology results indicated a massive retroperitoneal mucinous cystadenoma. INTERVENTIONS: The giant retroperitoneal cyst was smoothly excised during the second cesarean delivery for 1-step surgical treatment. OUTCOMES: Under the combined spinal and epidural anesthesia, a live female infant was delivered at 38 3/7 gestational weeks and the neonatal weight was 3200g. Under general anesthesia with endotracheal intubation, the giant retroperitoneal cyst was excised smoothly without complications. LESSONS: The findings of this case report contribute to the understanding of the diagnostic modalities, surgical approaches and postoperative considerations of giant retroperitoneal cysts associated with pregnancy.

Genomic analysis of primary epithelial neoplasms of the seminal vesicle identifies a subset of mucinous cystic tumours driven by KRAS mutations.

BACKGROUND: Carcinomas of the seminal vesicle are exceedingly rare, with a limited number of cases described in the literature. Reported cases span a relatively wide morphological spectrum, and their genomic features remain unexplored. DESIGN: In this study, we interrogated five primary epithelial neoplasms of the seminal vesicle using a targeted DNA sequencing platform (OncoPanel, 447 genes). RESULTS: The tumours included one adenocarcinoma with intestinal phenotype presenting after external beam radiation (for prostatic adenocarcinoma), one carcinoma with Müllerian-type clear cell phenotype, two mucinous tumours resembling low-grade mucinous neoplasms of the appendix (LAMN) and one mucinous cystadenoma. The post-radiation mucinous adenocarcinoma had genomic findings consistent with bi-allelic inactivation of TP53, as well as multiple copy-number changes with regional and chromosomal arm-level copy-number losses. The Müllerian-type clear cell carcinoma exhibited a complex copy-number profile with numerous regional and arm-level copy-number changes, as well as focal amplification events, including copy-number gain of 8q and amplification of a region within 20q13. Both low-grade mucinous tumours resembling LAMN harboured hot-spot gain-of-function KRAS variants (p.G12V and p.G13D) as the only genomic alteration. No genomic alterations were detected inthe lesion diagnosed as mucinous cystadenoma. CONCLUSION: Our results suggest that primary low-grade mucinous neoplasms of the seminal vesicle may represent a distinct entity equivalent to appendiceal counterparts, driven by gain-of-function variants of RAS GTPases. The remaining tumours showed genomic features that closely resembled those of neoplasms with comparable phenotypes and/or biological characteristics arising in other sites, suggesting that they could be managed similarly, with special considerations related to their anatomical location.

Neoplasia quística mucinosa hepática, reporte de un caso y análisis de la patología / Hepatic mucinous cystic neoplasm, case report and pathology analysis / Neoplasia cística mucinosa hepática, relatório de um caso e análise da patologia

Desde los primeros reportes en la bibliografía, la nomenclatura de las lesiones quísticas hepatobiliares se ha ido modificando, habiéndose descripto dos tipos de lesiones: las serosas y las mucinosas. En 2010 la Organización Mundial de la Salud estableció una nueva clasificación donde los términos cistoadenomas y cistoadenocarcinomas hepatobiliares son reemplazados por entidades más específicas como la neoplasia mucinosa quística y los tumores quísticos intraductales (neoplasia papilar intraductal, neoplasma tubulopapilar intraductal y neoplasma oncocitico papilar). En cuanto a la neoplasia mucinosa quística, la presencia de estroma ovárico le confiere características distintivas en lo patológico y biológico, siendo esto un requisito en la clasificación de la OMS. Esta característica lo diferencia de los hamartomas biliares, los quistes congénitos y la enfermedad de Caroli. Dichas neoplasias son infrecuentes, con una incidencia menor al 5% de las lesiones quísticas hepáticas y ocurren casi exclusivamente en mujeres, frecuentemente perimenopáusicas. Su potencial de malignización ha sido descrito, siendo éste la indicación de tratamiento quirúrgico resectivo. Presentamos el caso clínico de una paciente portadora de una neoplasia quística mucinosa hepática, catalogada como cistoadenoma hepático según la antigua clasificación.

Since the early reports in the literature, the nomenclature of hepatobiliary cystic lesions has been modified, with two types of lesions being described: serous and mucinous. In 2010, the World Health Organization established a new classification in which the terms hepatobiliary cystadenomas and cystadenocarcinomas were replaced by more specific entities such as mucinous cystic neoplasms and intraductal cystic tumors (intraductal papillary neoplasm, intraductal tubulopapillary neoplasm, and intraductal oncocytic papillary neoplasm). Regarding mucinous cystic neoplasms, the presence of ovarian stroma confers distinctive pathological and biological characteristics, which is a requirement in the WHO classification. This characteristic differentiates it from biliary hamartomas, congenital cysts, and Caroli's disease. Such neoplasms are rare, with an incidence of less than 5% of hepatic cystic lesions, and occur almost exclusively in women, often perimenopausal. Their potential for malignancy has been described, and this is the indication for surgical resection treatment. We present a clinical case of a patient with a mucinous cystic hepatic neoplasm, classified as a hepatic cystadenoma according to the old classification.

Desde os primeiros relatos na literatura, a nomenclatura das lesões císticas hepatobiliares tem sido modificada, sendo descritos dois tipos de lesões,asserosas e as mucinosas. Em 2010, a Organização Mundial da Saúdeestabeleceuuma nova classificação, naqual os termos cistoadenomas e cistoadenocarcinomas hepatobiliares foramsubstituídos por entidades mais específicas, como a neoplasia mucinosa cística e os tumores císticos intraductais (neoplasia papilar intraductal, neoplasma tubulopapilar intraductal e neoplasma oncocítico papilar). Em relação à neoplasia mucinosa cística, a presença de estroma ovarianoconfere características distintas do ponto de vista patológico e biológico, sendoesseum requisito naclassificação da OMS. Essa característica a diferencia dos hamartomas biliares, cistoscongênitos e doença de Caroli. Essas neoplasias são raras, comumaincidência menor que 5% das lesões císticas hepáticas, e ocorremquase exclusivamente em mulheres, frequentementeperimenopáusicas. Seu potencial de malignizaçãotem sido descrito, sendoesta a indicação para tratamentocirúrgicoressectivo. Apresentamos o caso clínico de uma paciente portadora de uma neoplasia cística mucinosa hepática, classificada como cistoadenoma hepático de acordocom a antigaclassificação.

[Pseudoascitis by giant ovaric cyst] / Pseudoascitis por quiste ovárico gigante.

The term pseudoascitis is used in patients who give the false impression of ascites, with abdominal distension but without peritoneal free fluid. The case of a 66-year-old woman, hypertensive and hypothyroid with occasional alcohol consumption, who consults due to progressive abdominal distension of 6 months of evolution and diffuse percussion dullness is presented, in whom a paracentesis is performed with the wrong endorsement of examination ultrasound that reports abundant intrabdominal free fluid (Fig. 1), later finding in the CT scan of the abdomen and pelvis an expansive process of cystic appearance of 295mm x 208mm x 250mm. Left anexectomy is programmed (Fig. 2) with pathological report of mucinous ovarian cystadenoma. The case report refers to the availability of the giant ovarian cyst within the differential diagnosis of ascites. If no symptoms or obvious signs of liver, kidney, heart or malignant disease are found and / or ultrasound does not reveal typical signs of intra-abdominal free fluid (fluid in the bottom of the Morrison or Douglas sac, presence of floating free intestinal handles), a CT scan and / or an RMI should be requested before performing paracentesis, which could have potentially serious consequences.

El término pseudoascitis, se utiliza en los pacientes que dan la falsa impresión de ascitis, con distensión abdominal pero sin líquido libre peritoneal. Se presenta el caso de una mujer de 66 años, hipertensa e hipotiroidea con consumo ocasional de alcohol, que consulta por distensión abdominal progresiva de 6 meses de evolución y matidez difusa a la percusión, en quien se realiza una paracentesis con el aval equivoco de examen ecográfico que informa abundante líquido libre  intrabdominal (Fig. 1), hallando posteriormente en TAC de abdomen y pelvis un proceso expansivo de aspecto quístico de 295mm x 208mm x 250mm. Se programa anexectomia izquierda (Fig. 2) con informe anatomopatológico de cistoadenoma mucinoso de ovario. La comunicación del caso remite a tener disponible el quiste ovárico gigante dentro de los diagnósticos diferenciales de ascitis. Si no se hallan síntomas o signos evidentes de insuficiencia hepática, renal, cardiaca o enfermedad maligna y/o la ecografía no revela signos típicos de líquido libre intrabdominal  (líquido en el fondo de saco de Morrison o de Douglas, presencia de asas intestinales libres flotantes), se debería solicitar una TAC y/o una RMI antes de realizar una paracentesis, la cual podría tener consecuencias potencialmente graves.

Rare association of epidermoid cyst of ovary with mucinous cystadenoma- A Case Report.

Epidermoid cyst is a rare benign neoplasm of the ovary, lined by stratified squamous epithelium, lacking skin, adnexal structures, and other teratomatous elements. On the other hand, mucinous cystadenoma is one of the most common benign ovarian neoplasm that microscopically shows cystic areas lined by tall columnar mucinous epithelium. Although its coexistence with other tumours, such as mature cystic teratoma, squamous cell carcinoma, clear cell adenocarcinoma, Brenner's tumour, serous cystadenoma, etc., have been reported, a combination of benign epidermoid cyst and mucinous cystadenoma has rarely been documented in literature. We report a case of coexistence of epidermoid cyst and mucinous cystadenoma in an ovarian cyst.

Primary retroperitoneal mucinous cystic neoplasm of borderline malignancy with KRAS and GNAS co-mutation: a case report.

Primary retroperitoneal mucinous cystic neoplasms are rare retroperitoneal tumors, which are histologically similar to mucinous cystic neoplasms of the ovaries. Only 31 cases of primary retroperitoneal mucinous cystic neoplasm with borderline malignancy (PRMCN-BM) have been reported (26 in women and five in men). We describe an additional male patient with PRMCN-BM. A 39-year-old man presented to our hospital with back pain. Twelve years earlier, he had undergone an orchiectomy for a germ cell tumor. Computed tomography showed a 6.9- × 4.4-cm cystic mass in the left pararenal space. Laparoscopic mass excision was performed, and a unilocular cystic mass was found in the pararenal space near the lower pole of the left kidney. A histopathological examination showed a cyst lined by atypical mucinous intestinal epithelium without stromal invasion. Targeted next-generation sequencing identified two hotspot mutations, with one each in the KRAS and GNAS genes. Outpatient follow-up 10 months after surgery showed no evidence of tumor recurrence. PRMCNs are extremely rare retroperitoneal neoplasms, especially in men. These neoplasms are rarely considered in the differential diagnosis of retroperitoneal masses, and their preoperative diagnosis is difficult. Evaluation of additional patients is required to better determine the prognosis of PRMCNs and the optimal postoperative follow-up.

Postmenopausal woman with 24 kilograms ovarian mucinous cystadenoma: a rare case report.

A case of a 53-year-old postmenopausal woman presenting a giant ovarian cystic mucinous tumor weighing 24 kg is reported here. When she was seen first at our outpatient clinic, she had gross abdominal distension since 2 years, and she complained of unbearable aggressive pain. Her computed tomography (CT) scan was done which came suggestive of ovarian serous cystadenoma of large massive size 35 x 40 x 32 cm with moderate ascites. On exploratory laparotomy, a giant, totally cystic, vascularized and smooth mass attached to the right ovary was encountered. On the postoperative tenth day, she was discharged without any problem. Histopathology report of the right ovarian cystic mass came suggestive of multiloculated cyst with capsule intact with Borderline Mucinous tumor of right ovary weighing 24 kg. This is both one of the largest known examples in the literature and the largest ovarian cyst ever seen at our institution.

Brenner Tumor of the Ovary: A 10-Year Single Institution Experience and Comprehensive Review of the Literature.

Brenner tumors (BTs) are surface-epithelial stromal cell tumors that are categorized by the World Health Organization as benign, borderline, and malignant. Due to the rarity of BTs, the published literature on these tumors is comprised primarily of case reports and small retrospective studies. We performed a pathology database review spanning the last ten years at our institution revealing nine reported benign BTs. We collected the clinical and pathological data of patients associated with those BTs, describing the clinical presentation and imaging results, and assessing the possible risk factors associated with them. The average age at diagnosis was 58 years. BTs were discovered incidentally in 7/9 cases. The tumor was multifocal and bilateral in 1/9 cases and ranged in size from 0.2 cm to 7.5 cm. Associated Walthard rests were found in 6/9 cases and transitional metaplasia of surface ovarian and/or tubal epithelium was found in 4/9 cases. One patient had an associated mucinous cystadenoma in the ipsilateral ovary. Another patient had an associated mucinous cystadenoma in the contralateral ovary. In conclusion, we found that Walthard rests and transitional metaplasia are common findings in association with BTs. Additionally, pathologists and surgeons need to be aware of the association between mucinous cystadenomas and BTs.

Primary Mucinous Tumors of the Ovary: An Interobserver Reproducibility and Detailed Molecular Study Reveals Significant Overlap Between Diagnostic Categories.

Primary ovarian mucinous tumors represent a heterogeneous group of neoplasms, and their diagnosis may be challenging. We analyzed 124 primary ovarian mucinous tumors originally diagnosed as mucinous borderline tumors (MBTs) or mucinous carcinomas (MCs), with an emphasis on interobserver diagnostic agreement and the potential for diagnostic support by molecular profiling using a next-generation sequencing targeted panel of 727 DNA and 147 RNA genes. Fourteen experienced pathologists independently assigned a diagnosis from preset options, based on a review of a single digitized slide from each tumor. After excluding 1 outlier participant, there was a moderate agreement in diagnosing the 124 cases when divided into 3 categories (κ = 0.524, for mucinous cystadenoma vs MBT vs MC). A perfect agreement for the distinction between mucinous cystadenoma/MBT as a combined category and MC was found in only 36.3% of the cases. Differentiating between MBTs and MCs with expansile invasion was particularly problematic. After a reclassification of the tumors into near-consensus diagnostic categories on the basis of the initial participant results, a comparison of molecular findings between the MBT and MC groups did not show major and unequivocal differences between MBTs and MCs or between MCs with expansile vs infiltrative pattern of invasion. In contrast, HER2 overexpression or amplification was found only in 5.3% of MBTs and in 35.3% of all MCs and in 45% of MCs with expansile invasion. Overall, HER2 alterations, including mutations, were found in 42.2% of MCs. KRAS mutations were found in 65.5% and PIK3CA mutations in 6% of MCs. In summary, although the diagnostic criteria are well-described, diagnostic agreement among our large group of experienced gynecologic pathologists was only moderate. Diagnostic categories showed a molecular overlap. Nonetheless, molecular profiling may prove to be therapeutically beneficial in advanced-stage, recurrent, or metastatic MCs.

Neuroendocrine Tumor Arising within Mature Cystic Teratoma of the Pancreas: Literature Review and Case Report.

Cystic teratomas are germ cell tumors most commonly found in the ovaries and testes. The pancreas, however, is very rare as a site of occurrence. Moreover, only two cases of cystic teratoma with concomitant neuroendocrine tumor have been reported to date. We report the case of a 33-year-old female who presented with abdominal pain. Computed tomography and magnetic resonance imaging of the upper abdomen revealed an 85 mm cystic tumor in the head of the pancreas. Cystic teratoma and mucinous cystadenoma were suggested as differential diagnoses. Cytopathologic analysis of endoscopic ultrasound-guided fine needle aspiration was consistent with mucinous cystadenoma. Therefore, the patient underwent surgical resection. Histologic analysis revealed a mature cystic teratoma of the pancreas with a concomitant neuroendocrine tumor. The patient is in great condition at 8 months follow-up. Cystic teratoma of the pancreas with a concomitant neuroendocrine tumor is an extremely rare condition. Surgical resection remains the mainstay of treatment as it provides a definitive diagnosis and no recurrences have been reported to date.

Endocrine cell micronests in an ovarian mucinous borderline tumor: a potential diagnostic pitfall for microinvasion.

The occurrence of endocrine cell micronests in ovarian tumors is rarely reported. To our knowledge, there are only three prior cases reported to date: one occurring in an ovarian mucinous cystadenoma, one in an ovarian mucinous cystadenofibroma, and another in an ovarian mucinous carcinoma with a predominant borderline component. This is a 27-year-old woman that presented with a one-month history of abdominal pain and fullness. Imaging studies revealed a large multiloculated cystic and solid mass measuring 23 cm occupying the majority of the pelvis and abdomen concerning for a primary ovarian malignancy. The patient underwent a right salpingo-oophorectomy with appendectomy. Histologic sections from the ovary showed a multiloculated, cystic and focally solid mass lined by gastrointestinal-type mucinous epithelium with variable degrees of proliferation accounting for greater than 10% of the tumor. In addition to the mucinous epithelial component, there were several foci of bland, monotonous epithelioid cells arranged in solid nests with focal tubular/acinar formation within the fibrous septa and mucinous epithelium. Immunohistochemical studies showed that these cells were positive for cytokeratin, EMA, and synaptophysin, while negative for inhibin. The Ki-67 proliferation index was low (<1%). The presence of endocrine cell nests associated with an ovarian mucinous neoplasm is a rare phenomenon. Whether this represents preservation of endocrine cells in the context of epithelial degeneration or an independent neoplastic component is unclear. Progression related to this endocrine cell proliferation is unlikely and the recognition of this phenomenon holds more diagnostic value than prognostic significance, as it could be confused with microinvasion or sex cord stromal elements.

Müllerian Mucinous Cystadenomas of the Ovary: A Report of 25 Cases of an Unheralded Benign Ovarian Neoplasm Often Associated With Endometriosis and a Brief Consideration of Neoplasms Arising From the Latter.

A subset of ovarian mucinous tumors demonstrates müllerian-type epithelium, with such lesions variably designated "endocervical-like" and seromucinous since their popularization based on a report of borderline examples in 1989. While müllerian mucinous borderline tumors and carcinomas have been highlighted in the literature, there has been minimal attention given to benign müllerian mucinous tumors, particularly müllerian mucinous cystadenomas. Given the paucity of literature describing the features of müllerian mucinous cystadenomas/cystadenofibromas, diagnostic difficulties may arise when papillary features are present and in cases that show a subtle transition from endometriosis. We thus reviewed 25 cases of müllerian mucinous cystadenoma/cystadenofibroma to highlight the notable characteristics of this entity, including gross, cytologic, and architectural features that aid in the distinction from müllerian mucinous borderline tumors as well as, rarely, metastatic tumors. The patients ranged in age from 26 to 85 yr old. Bilateral ovarian involvement was frequent (40%). The ovaries ranged from 2.3 to 26 cm in greatest dimension. Most were multicystic (18 cases) and contained tenacious mucoid material (14 cases). All cases demonstrated predominantly columnar mucinous epithelium with abundant pale-pink cytoplasm. A minor component of ciliated and endometrioid epithelium was seen in 15 and 2 cases, respectively. Broad papillary formations were frequently encountered (9 cases) as was epithelial papillary tufting comprising <10% of the tumor (6 cases). Endometriosis was present in 9 cases, with a transition from endometriosis to mucinous epithelium noted in 8 cases. This series highlights the morphologic features of a relatively uncommon, benign, endometriosis-associated ovarian tumor that may be confused with a müllerian mucinous borderline tumor or bland metastatic mucinous tumors. It also provides an argument for the terminology "müllerian mucinous cystadenoma" or "cystadenofibroma" rather than "seromucinous cystadenoma" due to the frequent association with endometriosis as well as the dominant mucinous epithelium.

Recurrent mucinous neoplasm arising in cesarean scar: A case report and review of literature.

Ovarian mucinous tumors are one of the common epithelial tumors in the ovary, but their recurrence is extremely rare. In a 37-year-old female patient who had had five operations in 7 years due to recurrent mucinous neoplasms, a mass extending to the umbilicus was recently detected during a routine examination. With this finding the patient underwent cystectomy, total abdominal hysterectomy, and left salpingo-oophorectomy. Two of the five operations were performed during cesarean delivery. In the recent surgical procedure, two cysts were removed. A 20 cm cyst in the pelvic region was diagnosed as a mucinous cystadenoma. The other cyst located in the myometrium was a mucinous cystadenoma with focal borderline change and arose in the previous cesarean scar. The authors present what is believed to be the first case of recurrent mucinous neoplasm arising within a cesarean scar. A review of the literature concerning the topic is also presented.