Abundant Extracellular Mucin Research Articles

Case series of pure mucinous breast carcinoma: A rare histopathological subtype

Pure mucinous breast carcinoma (PMBC) is even rarer and accounts for about 2% of all primary breast carcinoma. It is composed entirely of tumour cells with abundant extracellular mucin and without admixing of infiltrating ductal carcinoma. We studied a total of ten cases of Pure Mucinous Breast Carcinoma. Here we describes each case of demographic features and histopathological features of PMBC. The results of immunohistochemistry of Estrogen receptor (ER), Progesterone receptor (PR), Human epidermal growth factor receptor 2(HER-2neu) were also noted in this case series. All the cases were female and above 50 years of age. Out of 10 cases, 6 cases have the tumour’s location on the left side of the breast and 4 cases have the tumour’s location on the right side of the breast. All the cases belong to the lower grading and staging of the tumour. Only one case had positive lymph node status.Hormone receptor status of all the cases has ER & PR positive expression, HER-2neu negative expression and low Ki 67 labelling index. To conclude, PMBC was associated with lower-grade tumours, lower-stage, infrequent lymph node metastasis and luminal type A hormonal receptor status. These favourable findings suggest that PMBC has a better prognosis and may give a better response to hormonal therapy.

Metastatic Mullerian adenocarcinoma involving the pancreas initially misdiagnosed as an intraductal papillary mucinous neoplasm (IPMN): A case report, and lessons learned

Abstract Introduction/Objective Metastases to the pancreas from Mullerian primaries are rare and can be confused with primary pancreatic malignancies. Methods/Case Report A 49-year-old woman presented with right lower abdominal pain. She denied any prior history of malignancy but had undergone hysterectomy and bilateral salpingo-oophorectomy for unknown reasons. CT scan revealed an 8.9 cm predominantly cystic mass in the pancreas, highly suspicious of an invasive mucinous neoplasm. EUS-guided FNA of the pancreas showed large, complex papillary fronds of mucinous epithelial cells in a background of abundant extracellular mucin, findings that were interpreted as an intraductal papillary mucinous neoplasm (IPMN) with foci of high-grade dysplasia and possible adenocarcinoma. A subsequent PET/CT scan demonstrated a 3.9 cm hepatic mass and a 3.8 cm perihepatic lesion. FNA of the liver was interpreted as metastatic pancreatic adenocarcinoma. Despite aggressive treatment, her disease progressed. Molecular profiling of her liver tumor demonstrated a pathogenic KRAS G12D mutation and a PDGFRA variant of uncertain significance. Genomic (DNA) and transcriptomic (RNA) analysis indicated a 96% probability that the patient had ovarian or fallopian tube adenocarcinoma and a 4% probability of uterine endometrial adenocarcinoma rather than metastatic pancreatic adenocarcinoma. A panel of immunocytochemical stains was performed on the pancreas and liver FNAs. The tumor cells were strongly positive for CK7, CK19, ER, and WT1, focally positive for PAX8 (nuclear) and P53 (wild-type), and negative for CK20, CDX2, and SATB2. Results (if a Case Study enter NA) NA Conclusion These findings corroborated the molecular analysis suggesting that the patient had metastatic Mullerian adenocarcinoma rather than metastatic pancreatic adenocarcinoma. Her oncologic treatment was adjusted accordingly.

A Case of Primary Mucinous Adenocarcinoma of the Renal Pelvis: A Rare Occurrence

Adenocarcinoma represents only 1% of renal pelvis malignancies and can have three subtypes: tubulovillous, mucinous, and papillary non intestinal. Primary mucinous adenocarcinomas are very rare in the renal pelvis. We report a case of a 62-year-old male patient who presented with bilateral dull aching flank pain for 15 years. No flank tenderness was observed on clinical examination. Magnetic Resonance Imaging of the Kidney, Ureters, and Bladder (MRI KUB) showed marked dilation of the left kidney's pelvicalyceal system with irregular thinning of renal parenchyma, as well as a large filling defect. Percutaneous Nephrolithotomy (PCNL) obtained gelatinous material, and the Carcinoembryonic Antigen (CEA) level was found to be high. The patient underwent left radical nephrectomy, and gross examination of the kidney revealed staghorn calculi and multiple cavities filled with pus and gelatinous material. Microscopic examination showed atypical glands infiltrating the parenchyma with abundant extracellular mucin. Immunohistochemical (IHC) examination showed cytoplasmic positivity for CK7, CK20, and CEA, while PAX8 and GATA3 were negative. The Ki67 labeling index was more than 20%. The case was diagnosed as mucinous adenocarcinoma of the renal pelvis.

S2219 A Rare Subtype of Colorectal Cancer Presenting as a Contained Perforation

Introduction: Colonic perforation comprises 3-10% of the initial presentation of Colorectal Cancer (CRC). Signet Ring Cell Carcinoma and Mucinous Adenocarcinoma are 2 distinct subtypes which occur with a very low incidence of 10-20% and 0.9-4%, respectively. Both are usually diagnosed at an advanced stage and have an overall worse prognosis than other types of CRC. Here we present a rare case of colonic mucinous adenocarcinoma with signet ring cell features manifesting as a contained perforated intra-abdominal mass necessitating surgery. Case Description/Methods: A 60-year-old male presented with fatigue, shortness of breath and anemia with hemoglobin of 4.8 g/dL. A computed tomography (CT) scan of the abdomen and pelvis was obtained which showed an intraperitoneal mass with a central necrotic component and air, suggesting communication to the small bowel. Due to the initial concern of a possible contained perforation, colonoscopy was deferred despite the patient never having one previously. Ultimately, the patient underwent a diagnostic laparoscopy which showed a large intra-abdominal mass with a mucinous surface involving multiple parts of the small bowel and sigmoid colon. This mass was removed along with a small bowel and sigmoid colon resection. Pathology was notable for moderately differentiated mucinous adenocarcinoma of the sigmoid colon with focal signet ring features with negative margins and no evidence of lymphovascular invasion. He was eventually discharged with instructions to follow up with Oncology for further treatment. (Figure) Discussion: Mucinous adenocarcinoma is characterized by the presence of abundant extracellular mucin which accounts for at least 50% of the tumor volume. Signet ring cells have copious amounts of mucin in the cytoplasm and nuclei located at the cell periphery. These lesions are usually located in the right colon and share similar characteristics on CT imaging including segments of concentric bowel wall thickening and ulcerations. Studies have shown that even a minor signet-ring cell component in CRC was associated with higher patient mortality. This becomes evident as these tumors diffusely infiltrate the submucosa with full thickness involvement of the bowel wall and have a high propensity for pelvic, peritoneal and ovarian metastasis. Treatment centers on surgical resection with adjuvant chemotherapy showing some benefit. Our case highlights an atypical presentation of a rare subtype of CRC for which gastroenterologists should maintain a high index of suspicion.Figure 1.: (Top) Signet Ring Cells in background of mucus (from sigmoid colon) (Bottom) Computed Tomography (CT) scan showing an intra-abdominal mass with a contained perforation.

Mucinous adenocarcinoma of the prostatic urethra after brachytherapy for prostatic adenocarcinoma: a case series

Mucinous adenocarcinoma of the urethra is extremely rare, even more so in a setting of postradiation therapy, with only 3 cases reported up to date including the first case published by our group in 2011. In the present study, we included the long-term follow-up on our previously reported case and report 3 additional cases. This is the first case series to date of this rare disease entity. The aim of this study is to review the clinicopathologic features of mucinous adenocarcinoma of the prostatic urethra in patients after receiving brachytherapy for prostatic adenocarcinoma. We identified 4 patients with a mean age of 72 years, and a mean interval of 14.8 years from brachytherapy for prostate carcinoma (grade group 1). Patients presented with hematuria or urinary retention. A colonoscopy was performed in three-fourth of patients and was within normal limits. Three patients underwent cystoprostatectomy and 1 had a transurethral resection of the prostate. On gross examination, only tumor formed a 3.5cm tan-gray, ulcerated, friable, and necrotic mass and 2 displayed either irregular red granular or thickened areas within the prostatic urethra. Abundant extracellular mucin pools dissecting the prostatic stroma were present in all tumors, with clusters of tumor cells floating in the mucin. The mucin pools were lined by pleomorphic pseudostratified columnar mucinous epithelium. Tumors were diffusely positive for CK20, CDX2 (4/4), and AMACR (2/2); they focally expressed CK7 (2/4), and lacked nuclear β-catenin expression (3/3). PSA, PSAP, NKX3.1, p63, and GATA3 were negative in the tumors tested. Among the 3 patients who underwent radical surgery, 2 had stage 2 tumors (confined to the prostatic urethra and prostate), and 1 had a stage 3 tumor, with seminal vesicle involvement. All 4 patients were alive without disease with a mean follow-up of 4.9 years. In conclusion, brachytherapy-associated mucinous adenocarcinoma of the prostatic urethra displays intestinal-type features as its non-radiation-related counterpart. It appears to lack a villous adenoma component, displays a different immunohistochemical profile with diffuse CK20 and CDX2 positivity, and is associated with lower stage and less aggressive behavior.

Abstract 6035: Genetically-engineered mouse model for colonic neoplasia presenting mucinous and microsatellite unstable phenotype

Abstract Background and Aim: Mucinous colorectal adenocarcinoma (CRC) is characterized by abundant extracellular mucin which occupies more than 50% of the tumor volume. Mucinous CRCs account for 10% of all CRCs and are likely to be microsatellite unstable including Lynch syndrome. Mucinous CRCs metastasize less frequently. However, once they metastasize, they exhibit resistance to cytotoxic chemotherapeutics, and are associated with poorer prognosis. Although there are some issues to be addressed in mucinous CRCs, mouse models are lacking for mucinous CRCs. Here, we report genetically-engineered mouse models (GEMMs) for mucin-producing colonic tumors with microsatellite instability (MSI), resembling human mucinous CRCs. Method: To induce genetic alterations specifically in colonic epithelial cells, we used CDX2P-G19Cre transgenic mice. In this mouse model, a 9.5-kb fragment in the CDX2 promoter lesion (CDX2P9.5) regulates Cre expression specifically in colonic epithelium (Hinoi et al. Cancer Research 2007). In addition, 19 guanine nucleotides are inserted just after the first ATG, and Cre only expresses in the epithelial cells in which the number of the guanine tract stochastically turns a multiple of three. This mechanism helps our GEMMs to avoid embryonic death due to the genetic events we introduce. We have also reported that tumors in CDX2P9.5-G19Cre;Apcflox/flox mice have an abnormality in two of four MSI markers, suggesting that the tumors are driven by MSI (Sasada et al. PLoS One 2015). TGFBR2 mutation is frequently seen in human MSI CRCs, and inactivation of both Tgfrbr2 and Apc by Villin-Cre results in small intestinal neoplasm producing mucin. Therefore, to test if Tgfbr2 conditional knockout affects the mucin-producing phenotype in the context of MSI-high in this mouse model, we generated CDX2P-G19Cre;Apcflox/+;Tgfbr2flox/flox. Results: In CDX2P-G19Cre; Apcflox/+; Tgfbr2 flox/flox mice, colonic neoplasia developed in 27 out of 40 mice. Approximately 60% of the tumors are well-differentiated adenocarcinoma producing mucin, while the remaining 40% are regular colonic adenomas. In these mucinous adenocarcinomas, tumor cells invade into the muscular layer. We also confirmed the immunoreactivity of β-catenin in cytoplasm and nuclei at the invasive front of the tumors in IHC analysis, indicating that these tumors are driven by abnormal Wnt activity. Nearby to the invasive front, there were mucin that were positive for a PAS reaction. Conclusion: Mucin-producing adenocarcinomas develop in CDX2P9.5-G19Cre;Apcflox/+; Tgfbr2flox/flox mice. This GEMM is a potential mouse model recapitulating human mucinous and microsatellite unstable colorectal adenocarcinoma. The precise mechanism in which mucinous adenocarcinoma develops needs to be elucidated by genomic and transcriptomic analyses. Citation Format: Haruki Sada, Takao Hinoi, Hiroaki Niitsu, Masashi Miguchi, Naoya Sakamoto, Naohide Oue, Hirotaka Tashiro, Hideki Ohdan. Genetically-engineered mouse model for colonic neoplasia presenting mucinous and microsatellite unstable phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6035.

Pulmonary Glandular Papilloma with Abundant Extracellular Mucin and BRAF V600E, AKT1 E17K Mutations: A Case Report

Pulmonary Glandular Papilloma with Abundant Extracellular Mucin and BRAF V600E, AKT1 E17K Mutations: A Case Report

Intraductal papillary mucinous neoplasm of the pancreas: Cytomorphology, imaging, molecular profile, and prognosis.

Intraductal papillary mucinous neoplasm (IPMN) constitutes up to 20% of all pancreatic resections, and has been increasing in recent years. Histomorphological findings of IPMN are well established; however, there are not many published papers regarding the cytological findings of IPMN on fine needle aspiration (FNA) specimens. We review the cytomorphological features, molecular profile, imaging findings, and prognosis of IPMN. The English literature was thoroughly searched with key phrases containing IPMN. IPMN is a rare entity, affecting men and women equally and is usually diagnosed at the age of 60-70years. The characteristic imaging features include a cystic lesion with associated dilatation of the main or branch pancreatic duct, and atrophy of surrounding pancreatic parenchyma. Cytomorphological features of IPMN include papillary fragments of mucinous epithelium in a background of abundant thick extracellular mucin, a hallmark feature. IPMNs should be evaluated for high-grade dysplasia, which manifests with nuclear atypia, nuclear moulding, prominent nucleoli, nuclear irregularity, and cellular crowding. Molecular profiling of IPMN along with carcinoembryonic antigen and amylase levels is useful in predicting malignancy or high-grade dysplasia arising in IPMN. Overall, the prognosis of IPMN is excellent except in those cases with high-grade dysplasia and malignant transformation. Postoperative surveillance is required for resected IPMNs. IPMN requires a multidisciplinary approach for management. Cytomorphological findings of IPMN on FNA, in conjunction with tumour markers in pancreatic fluid cytology and imaging findings, are of paramount importance in clinical decision-making for IPMN.

Resistance to Cell Death in Mucinous Colorectal Cancer-A Review.

Simple SummaryMucinous colorectal cancer is characterised by abundant mucin glycoprotein production and is associated with resistance to chemotherapy-based treatments. This review outlines mechanisms for cell death resistance present in mucinous colorectal cancer including glycoprotein interactions with cell survival and cell apoptotic pathways. Further mechanisms are explored, including alterations in the expression of chemotherapy metabolism and resistance genes. This review identifies directions for future investigation of mucinous colorectal cancer and novel treatment strategies.Mucinous colorectal cancer (CRC) is estimated to occur in approximately 10–15% of CRC cases and is characterized by abundant extracellular mucin. Mucinous CRC is frequently associated with resistance to apoptosis. Inferior prognosis is observed in mucinous CRC, particularly in rectal cancer and metastatic cases. Mucins are heavily glycosylated secretory or transmembrane proteins that participate in protection of the colonic epithelium. MUC2 overexpression is a hallmark of mucinous CRCs. Mucinous CRC is associated with KRAS and BRAF mutation, microsatellite instability and the CpG island methylator phenotype. Mutations of the APC gene and p53 mutations which are characteristic non-mucinous colorectal adenocarcinoma are less common in mucinous CRC. Both physical and anti-apoptotic properties of mucin provide mechanisms for resistance to cell death. Mucin glycoproteins are associated with decreased expression of pro-apoptotic proteins, increased expression of anti-apoptotic proteins and increased cell survival signaling. The role for BCL-2 proteins, including BCL-XL, in preventing apoptosis in mucinous CRC has been explored to a limited extent. Additional mechanisms opposing cell death include altered death receptor expression and altered mutation rates in genes responsible for chemotherapy resistance. The roles of alternate cell death programs including necroptosis and pyroptosis are not well understood in mucinous CRC. While the presence of MUC2 is associated with an immunosuppressive environment, the tumor immune environment of mucinous CRC and the role of immune-mediated tumor cell death likewise require further investigation. Improved understanding of cell death mechanisms in mucinous CRC may allow modification of currently used regimens and facilitate targeted treatment.

Mucinous Rectal Adenocarcinoma in a Urutu Snake (Bothrops alternatus)

A 15-year-old captive female Urutu snake (Bothrops alternatus) was presented with anorexia, apathy, dehydration, pale mucous membranes and marked enlargement of the caudal third of the coelomic cavity. Radiographs and ultrasonography were suggestive of faecal impaction or neoplasia. Post-mortem findings consisted of solid faecal impaction of the intestines, secondary to obstruction caused by a rectal tumour. Cytological examination of impression smears of the tumour revealed polygonal to round neoplastic cells arranged in clusters in an abundant extracellular mucinous matrix. Histologically, there was transmural growth of neoplastic epithelial cells arranged in small nests or individually and immersed in abundant extracellular mucin lakes. The neoplastic cells were immunopositive for cytokeratin. Clinical and pathological aspects indicated a diagnosis of mucinous rectal adenocarcinoma.

Clinicopathological and Molecular Analysis of 45 Cases of Pure Mucinous Breast Cancer.

Pure mucinous breast carcinoma (PMBC) is characterized by clusters of tumor cells floating in abundant extracellular mucin and can be classified into paucicellular (Type A) and hypercellular (Type B) subtypes. However, the clinicopathological and genomic differences between these two subtypes have not been well characterized. We retrospectively investigated the clinicopathologic features of 45 cases of surgically removed PMBC (31 Type A and 14 Type B). We also performed whole-exome sequencing (WES) in eight cases of PMBC. We found that Type B PMBC occurs at an older age and shows more aggressive clinical behavior than Type A. WES analysis revealed that HYDIN was the most frequently mutated gene in both types of PMBC. Although Type B PMBC showed a tendency toward more frequent genetic alterations, there were no statistically significant differences between the two subtypes in single nucleotide variants or insertions or deletions of bases associated with moderate or high effects. Our results provide additional evidence that PMBCs are clinicopathologically and genetically heterogeneous and lack pathognomonic genetic alterations. Further, Type B PMBC is more frequently associated with lymph node metastasis than Type A.

Pathological aspects of mucinous cholangiocarcinoma: A single-center experience and systematic review.

Cholangiocarcinoma is a malignant neoplasm originating from the biliary epithelium. Its incidence is highest in Southeast Asia, especially in Thailand. Mucinous intrahepatic cholangiocarcinoma (mucinous iCCA), characterized by an abundant extracellular mucin pool accounting for at least 50% of total tumor volume, is an extremely rare variant of such malignancy and is notorious for rapid progression and dismal prognosis. We conducted an 11-year retrospective analysis of resected mucinous iCCAs from our institution with a systematic review on mucinous iCCAs and combined hepatocellular-mucinous cholangiocarcinoma (cHCC-mCCA). There were four resected mucinous iCCA specimens at our institution (prevalence = 0.5%). Most of the patients were male. The clinicopathological characteristics were variable. The diagnosis of mucinous iCCAs could not be rendered without pathological evaluation. Either intraductal papillary neoplasm or biliary intraepithelial neoplasia was present in three out of four cases. One patient passed away at 11 months following liver resection. A total of 19 mucinous iCCAs and four cHCC-mCCAs from previously published literature were analyzed. The 1-year mortality rate of mucinous iCCAs from our series and published literature is 35%. The present study confirmed that mucinous iCCA is an exceedingly uncommon variant of iCCA. The differential diagnoses include metastatic carcinoma with mucinous component and cHCC-mCCA.

Primary Gallbladder Signet-ring Cell Carcinoma with Abundant Extracellular Mucin

Primary Gallbladder Signet-ring Cell Carcinoma with Abundant Extracellular Mucin

Undifferentiated (Anaplastic) Carcinoma of The Thyroid with Abundant Mucin Production

Most pathologists are unaware that thyroid gland also produces mucin; often associated with typical thyroid carcinoma rather than primary mucinous neoplasm. We report an unusual case of anaplastic carcinoma of thyroid presenting with abundant extracellular mucin. A 65 year old lady presented with painless, neck swelling since 7-8 months. Thyroid function tests were within normal limits. Imaging suggested neoplastic aetiology of thyroid. Cytology revealed abundant extracellular mucin with occasional large atypical cells. Hence, metastasis followed by primary mucinous thyroid carcinoma was considered. After excluding secondary neoplasms, total thyroidectomy with lymphadenectomy was performed. Histopathology revealed an infiltrative tumour with abundant mucin & necrosis amidst fibrotic bands. Tumour cells were arranged in sheets, with features of anaplasia. Focus of papillary thyroid carcinoma also identified. Mucicarmine and Alcian blue special stains were positive. Immunohistochemistry results of positive cytokeratin and negative TTF1, thyroglobulin and calcitonin confirmed our results.

642P - Frequent BRAF, GNAS and SMAD4 mutations identified in colorectal mucinous carcinomas

BackgroundColorectal mucinous carcinoma (MAC) is a distinct subtype of colorectal carcinoma (CRC) accounting for approximately 10-20% of all CRCs. Mucinous carcinomas characterized by the presence of abundant extracellular mucin which occupies at least 50% of the tumour volume. Patients are often diagnosed at an advanced stage in young patients showing a poor prognosis with the 3-year overall survival rate of 57%. Although clinicopathologic findings of colorectal MACs are relatively well known, their molecular alterations have not elucidated. We investigate molecular alterations of colorectal MACs revealed by next-generation sequencing (NGS). MethodsWe retrospectively reviewed cases of CRCs with mucinous component and 111 MACs subject to molecular profiling using NGS on the Ion Proton (Thermo Fisher Scientific). We examined substitutions and small indels in 409 cancer-related genes using Ion ampliseq Cancer Hotspot and Ion ampliseq Comprehensive Cancer panels. ResultsOf the 111 patients included in the analysis, 60 (54.1%) were male: the median age was 58 years. BRAF was mutated in 17% of colorectal MACs (19 of 111) and 9.0% of CRCs (18 of 200), V600E mutations were predominantly identified in MACs, representing 95% (18 of 19) of BRAF mutated cases (p=0.0438). GNAS mutations were frequently detected in 14.4% of colorectal MACs (19 of 111) and 1.5% of CRC (3 of 200), R201C and R201H were more commonly mutated, representing 95% (18 of 19) of GNAS mutated cases (p<0.001). SMAD4 mutations were frequently noted in colorectal MACs compared with those of CRCs (24 of 111 vs. 22 of 200, p=0.0187). ConclusionsThis study demonstrates distinct genomic differences in colorectal MACs compare with CRCs. The genomic profiling of colorectal MACs revealed by NGS can identify potentially targetable molecular alterations in the majority of colorectal MACs (95.5%). Overall, colorectal MACs harbor relatively high frequencies of BRAF, GNAS, and SMAD4 mutations compared with those of CRCs. This distinct activating or inactivating mutations of these genes suggest promising consideration of targeted therapy by inhibiting related pathways in patients with advanced colorectal MACs. Legal entity responsible for the studySun Mi Lee. FundingJeju National University Hospital. DisclosureThe author has declared no conflicts of interest.

Calcified mucinous adenocarcinoma of the stomach metastatic to the iris: a case report

BackgroundGastric cancer has a wide spectrum of clinical features, imaging manifestations, and pathology. Punctate calcifications in gastric cancer are infrequent but are usually found in mucinous adenocarcinoma. However, there have only been a few autopsy case reports describing the correlation between the radiology and pathology findings of calcified mucinous adenocarcinoma of the stomach. We present an autopsy case of mucinous gastric adenocarcinoma with iris metastases as the initial symptom.Case presentationA 74-year-old Japanese woman presented with blurred vision. Her treating ophthalmologist diagnosed acute iritis with secondary glaucoma. The histopathological and immunohistochemical features of a trabeculectomy specimen favored metastatic carcinoma, most likely of gastrointestinal tract origin. Esophagogastroduodenoscopy revealed multiple irregularly shaped ulcerative lesions, multiple erosions, and thickened folds in the corpus of her stomach. Histologic examination of a gastric tissue specimen obtained by endoscopic biopsy revealed poorly differentiated carcinoma with signet ring cell features. Computed tomography revealed a tumor with multiple punctate calcifications in the thickened gastric wall with diffuse low attenuation and multiple lymph node metastases, including the para-aortic lymph nodes, and peritoneal dissemination. She was diagnosed with stage IV gastric cancer (T4N3M1) and underwent seven cycles of 5-weekly TS-1, a novel oral fluoropyrimidine derivative, plus cisplatin therapy. Serial follow-up computed tomography revealed successive increases in the gastric wall calcifications. Her disease stabilized, but she died of aspiration pneumonia 8 months after the first visit. Autopsy tissue specimens had miliary, punctate calcifications present in abundant extracellular mucin pools in the submucosa, corresponding to the thickened low-attenuating middle layer on computed tomography. The final diagnosis was mucinous gastric adenocarcinoma because mucinous adenocarcinoma is diagnosed when more than half of the tumor area contains extracellular mucin pools.ConclusionsWe report the pathology and computed tomography imaging characteristics of a case of calcified mucinous adenocarcinoma of the stomach metastatic to the iris, including findings at autopsy. Metastatic carcinomas in the iris originating in the stomach are exceedingly rare. Multiple punctate calcifications were present in pools of extracellular mucin, a diagnostic clue for mucinous adenocarcinoma. Possible mechanisms underlying scattered punctuate calcifications in gastric mucinous adenocarcinoma warrant further investigation.

Myometrial myxoidosis: A rare case seen in a patient of primary subfertility

Myxoid mesenchymal lesions of the uterus are generally restricted to tumors. Myometrial myxoidosis is a rare benign tumor of the uterus. We report a case of myometrial myxoidosis diagnosed postoperatively with histopathological report in a 27-year-old female with primary subfertility who had undergone myomectomy and adenomyomectomy. On gross examination the tumor was 13.5x8x2.5 cm in size. Microscopically, it showed interlacing bundles of smooth muscles intersecting each other. Sections from separate tissue showed muscle fascicles which were separated by abundant extracellular mucin producing a striking myxoid appearance (myxoidosis).&#x0D; Only few cases of myometrial myxoidosis have been reported in literature. Of them, some were associated with lupus erythematosus and some with neurofibromatosis.

Abstract P1-07-29: Clinicopathologic characteristics and prognostic factors of pure mucinous breast cancer

Abstract Background: Mucinous carcinoma of the breast is a uncommon particular type of breast cancer and comprises approximately 4% of all invasive breast cancers. It is charactarized by abundant extracellular mucin production and present a more favorable prognosis than IDC-NOS. Pathologically, mucinous carcinoma is divided into two subtypes : pure and mixed. In this study, we reviewed the clinicopathologic characteristics and prognostic factors of pure mucinous carcinoma. Methods: We reviewed the 23 years cumulative data of pure mucinous breast cancer patients from database of the Breast Cancer Center at ASAN medical center, Korea, between 1989-2011, retrospectively. Total 386 pure mucinous carcinoma cases were reviewed to analyze clinicopathologic characteristics and prognosis. Result: Total of 386 patients with pure mucinous breast cancer were identified. Mean age was 46.7. 149 patients underwent modified radical mastectomy and 236 underwent breast-conserving therapy. The T-stage was T1 in 187 patients, T2 in 178 patients, T3 in 17 patient and T4 in 4 patients. Node negative was 325 and node positive was 61. Estrogen receptor was positive in 342 and negative in 29. Progesterone receptor was positive in 276 and negative in 95. HER-2 was positive in 47 and negative in 273. 152 patients received adjuvant chemotherapy and 240 patients received adjuvant radiotherapy. 351 patients received hormone therapy and among these patients, 231 patients were treated with Tamoxifen alone, 81 were Tamoxifen with ovarian function suppression, 37 were AI only and one patient was ovarian function suppression only. The 5 year disease free survival rate was 93.3%, 5 year cancer specific survival rate was 98.2% and 5 year overall survival rate was 96.6%. Univariate analysis showed that ER status, nodal status and Her2 status were appear to be prognostic factor of Disease free survival rate. Using Cox regression, result of multivariate analysis revealed that only nodal status is the most significant prognostic factor for survival rate. Conclusions: Pure mucinous carcinoma of the breast is a rare subtype with a favorable prognosis. Nodal status rather than ER status, Her2 status are considered to be the most significant prognostic factor of pure mucinos breast cancer. Citation Format: Gwark SC, Lee JW, Lee SB, Sohn G, Kim J, Chung IY, Kim HJ, Ko BS, Son BH, Ahn SH. Clinicopathologic characteristics and prognostic factors of pure mucinous breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-29.

Primary Mucinous Adenocarcinoma Of Urinary

A 60 year old male, chronic smoker and alcoholic since 30 years came with complaints of gross hematuria since 2 days. Clinically he was alright. CT scan showed a bladder mass reaching outside the serosa with no nodal involvement. Wide local excision was done with partial cystectomy. Growth was found on the dome of the bladder and was sent for histopathology. Sections showed tumour cells arranged in papillary pattern and lined by pseudostratified tall columnar epithelium filled with mucin and goblet cells at places. Intervening stroma shows abundant extracellular mucin, areas of necrosis and tumour cells showing malignant features with few areas with signet cells. Mucosal margins were also involved. Case diagnosed as Well differentiated mucinous Adenocarcinoma- Bladder. DOI: 10.21276/APALM.1610

Goblet cell carcinoid of the appendix - An interobserver variability study using two proposed classification systems.

Goblet cell carcinoid (GCC) is an uncommon tumor of the vermiform appendix. Due to a broad spectrum of morphological differentiation, subclassification and grading of GCCs remains an area of controversy. Two separate systems have proposed classifying GCC tumors into three (classical GCC; adenocarcinoma ex-GCC, signet ring cell type; adenocarcinoma ex-GCC, poorly differentiated carcinoma type) OR two subgroups (low and high grade GCC) based on morphological criteria. We independently compared the inter-observer variability associated with each classification system. Overall, both systems had moderate interobserver agreement, with the two-tiered system (κ=0.54) performing slightly better than the three-tiered system (κ=0.42). GI-specialist pathologists had substantial agreement for both two and three-tiered systems (κ=0.65 vs. 0.65). Non-GI trained pathologists had lower overall agreement than GI trained pathologists, but their agreement was better using the two-tiered system (κ=0.44) than the three-tiered system (κ=0.22). A sub-analysis of 6 cases with a high rate of discordant classification revealed several challenges that exist in applying current criteria, including differentiating "goblet" vs. "signet ring" cell morphology, applying a 1 mm2 criteria to multifocal non-contiguous glandular and single infiltrating cell architecture, differentiating fibro-inflammatory stroma from desmoplastic stroma, and solid architecture in cases with abundant extracellular mucin, and distinguishing "reactive" nuclear atypia from true "cytologic atypia". Despite these challenges, the study identified better agreement among GI pathologists than non-GI trained pathologists. While GI pathologist review may be helpful, further research on objective classification criteria remains an area of interest.