Signet-ring Adenocarcinoma Research Articles

A case of Russell body gastritis associated with psychiatric disorder

Abstract Introduction/Objective Russell body gastritis is a benign and rare entity characterized by infiltration of lamina propria with plasma cells stuffed with spherical eosinophilic cytoplasmic inclusions known as Russell bodies which represent immunoglobulins. Russell bodies accumulate due to dysfunction in secretion pathway of plasma cells. Plasma cells with Russell bodies are also termed Mott cells. Although exact etiology is unknown, but it can be seen in association with other conditions like mucosa associated lymphoid tissue (MALT) lymphoma, multiple myeloma and plasmacytoma. This condition most commonly affects the antrum and may present as erythema or sometimes nodular lesion. Definitive diagnosis is based on histology. Methods/Case Report A middle-aged male with past medical history significant for polysubstance use disorder, bipolar disorder, and osteoarthritis was evaluated for bleeding per rectum and dyspepsia in the setting of chronic nonsteroidal anti-inflammatory drugs (NSAID) and ethanol use. Physical examination was remarkable for an external hemorrhoid and complete blood count showed anemia. Upper GI endoscopy and colonoscopy was performed. Patchy erythema was seen in antrum and duodenal bulb, and colonoscopy was unremarkable. Microscopic examination showed numerous plasma cells with Russell bodies (Mott cells) in the lamina propria and mild chronic inflammation in gastric mucosa. H. Pylori was negative by immunohistochemistry (IHC). Plasma cells were polyclonal and positive for CD138, and negative for cytokeratin which excluded plasmacytoma and signet-ring adenocarcinoma, respectively. Patient was placed on proton pump inhibitor therapy and discharged. Results (if a Case Study enter NA) Russell body gastritis can be seen in patients with and without H. Pylori infection. Cytokeratin, kappa and lambda immunohistochemistry stains, and gene rearrangement studies may be needed to exclude frequent lesions that may enter in the differential diagnosis. Long term effects and clinical significance of russell bodies accumulation is yet to be determined. Conclusion Russell body gastritis is a rare morphologic variant of chronic gastritis that may enter in the differential diagnosis with other more serious lesions. A careful morphologic examination and occasionally IHC stains / molecular studies are needed to make the correct diagnosis.

S3970 Crohn’s Disease Mimic: A Case Report of Signet Ring Adenocarcinoma of the Appendix

S3970 Crohn’s Disease Mimic: A Case Report of Signet Ring Adenocarcinoma of the Appendix

Ileal Signet Ring Adenocarcinoma in Crohn's Disease: Unanticipated Diagnosis After Surgical Resection of a Symptomatic Stricture.

Ileal Signet Ring Adenocarcinoma in Crohn's Disease: Unanticipated Diagnosis After Surgical Resection of a Symptomatic Stricture.

A review of Radiological Imaging Features to ameliorate radiologists’ knowledge of Krukenberg Tumor (KT)

Object: Aim is to delineate the major radiological findings with US, CT and MR of the Krukenberg tumor. Method: Revision of the literature. Introduction: A Krukenberg tumor refers tipically to a gastrointestinal cancer that metastasizes to the ovaries; this tumor was named after Krukenberg, who originally described this pathologic condition of the ovaries in 1896. The prognosis of this tumor is uniformly poor.[1] Discussion: Krukenburg tumor (KT)is a metastatic malignancy of the ovary characterized by mucin-rich signet-ring adenocarcinoma that primarily arises from a gastrointestinal site in most cases and less commonly from other sites. Often these tumors are bilateral (over 80%), given their metastatic nature. The images of a Krukenberg tumor highlight that the masses are mostly: bilateral, lobulated, solid/mixed solid and cystic. Conclusion: On imaging, Krukenberg tumor should be suspected when bilateral solid, mixed solid and cystic, or predominantly cystic ovarian masses are seen in the presence of a known or suspected gastrointestinal primary malignancy. Krukenberg tumors should also be considered when a ovarian mass shows the so-called “lead vessel sign”[1-12-15].

A review of Radiological Imaging Features to ameliorate radiologists’ knowledge of Krukenberg Tumor (KT)

Object: Aim is to delineate the major radiological findings with US, CT and MR of the Krukenberg Tumor. Method: Revision of the literature. Introduction: A Krukenberg Tumor refers tipically to a gastrointestinal cancer that metastasizes to the ovaries; this tumor was named after Krukenberg, who originally described this pathologic condition of the ovaries in 1896. The prognosis of this tumor is uniformly poor.[1] Discussion: Krukenburg tumor (KT)is a metastatic malignancy of the ovary characterized by mucin-rich signet-ring adenocarcinoma that primarily arises from a gastrointestinal site in most cases and less commonly from other sites. Often these tumors are bilateral (over 80%), given their metastatic nature. The images of a Krukenberg Tumor highlight that the masses are mostly: bilateral, lobulated, solid/mixed solid and cystic. Conclusion: On imaging, Krukenberg Tumor should be suspected when bilateral solid, mixed solid and cystic, or predominantly cystic ovarian masses are seen in the presence of a known or suspected gastrointestinal primary malignancy. Krukenberg Tumors should also be considered when a ovarian mass shows the so-called “lead vessel sign”[1-12-15].

Krukenberg Tumour with Skin Metastasis: A Rare Calamitous Disease

Krukenberg tumour with cutaneous metastasis is a rare entity signifying a disseminated disease with poor prognosis. The prevalence of Krukenberg tumour differs among populations. In regions with a high prevalence of gastric carcinoma, such as Japan, these tumours comprise up to 17.8% of all ovarian carcinomas. We report a case of 42-year-old female patient who presented with lower abdomen pain and nodular lesions over the skin after undergoing total gastrectomy for gastric carcinoma eighteen months back. Through a review of relevant literature and case studies, this paper elucidates the clinical significance of cutaneous metastasis in Krukenberg tumors and highlights the importance of multidisciplinary approaches in managing this condition effectively. Keywords: poor prognosis, signet ring adenocarcinoma, gastric adenocarcinoma, skin metastasis, krukenberg tumour

IMMUNOHISTOCHEMICAL EXPRESSION OF THYMIDYLATE SYNTHASE IN DIFFERENT GRADES OF COLORECTAL CARCINOMA

Objective: To Evaluate the Immunohistochemical Expression of Thymidylate Synthase in different grades and histological types of Colorectal Carcinoma.
 Study Design: Cross sectional, Descriptive study
 Place and duration of study: This study was conducted from June 2019 to November 2020 in the Department of Pathology at Postgraduate Medical Institute Lahore / Lahore General Hospital. 
 Methodology: Forty resected gut specimens diagnosed on light microscopy as Colorectal adenocarcinoma were included on the basis of non-probability, consecutive sampling technique. Cases were reviewed and histological typing and grading was done separately by two competent Histopathologists. Immunohistochemical staining for Thymidylate Synthase was performed. Results of Thymidylate Synthase immunostaining were interpreted by the two observers based on the cytoplasmic staining of tumor cells. Thymidylate Synthase expression was quantified through a visual grading system depending upon the staining intensity and percentage of stained cells. 
 Results: Out of 40 cases of adenocarcinoma, majority of the patients (45%) belong to the age range of 51-60 years. There were 31(77.5%) male patients while 9(22.5%) were females. 28 (22%) cases were classified as low grade while 12 (11%) cases were reported as high-grade carcinomas. Amongst these Thymidylate Synthase expression was seen in 78.6% of low-grade carcinoma and 91.6% of high-grade carcinomas. Regarding histological subtyping, 23(57.5 %) cases were identified as non-mucinous adenocarcinomas, (9)22.5% as mucinous adenocarcinoma and (8) 20% as signet ring adenocarcinoma. Thymidylate Synthase expression was found to be similar i.e., 78% in non- mucinous as well as mucinous carcinomas however, 100% positivity was noticed in signet ring carcinomas. The overall positivity for Thymidylate Synthase was found to be 82.5%. 
 Conclusion: Colorectal carcinoma was prevalent among males of 51-60 years of age. 82.5% cases of colorectal carcinoma expressed Thymidylate synthase receptors and its expression was found to be higher in high grade tumors.

Incidental precancerous and cancerous neoplasms in routine cholecystectomy specimens – A fascinating series of cases in a tertiary care center

Laparoscopic cholecystectomy is one of the most commonly performed surgeries for benign gall bladder pathologies. Pre-cancerous and malignant gall bladder neoplasms often have overlapping non-specific clinical manifestation in their early stages. Radiological findings are also non-specific in the early stages with the presence of cholelithiasis in a significant proportion of cases. Cholelithiasis is said to be one of the important comorbid risk factors for gall bladder carcinoma (GBC) as a source of constant irritation to biliary mucosa. In such cases, cholecystectomy done for benign indications may lead to a histopathological diagnosis of incidental gall bladder carcinomas. Pancreaticobiliary type of adenocarcinoma is the most common subtype of GBC with two described cases in this series. Invasive foci need to be ruled out in. All cases of high-grade biliary intraepithelial neoplasia as were seen in the third case. Intracholecystic papillary neoplasm is a recently described entity with one reported case in this series that was associated with invasive adenocarcinoma. Signet ring adenocarcinoma is a rarely encountered adenocarcinoma in gall bladder with worse outcome. One such case has been described here where the patient has succumbed to death within 3 months of surgery and during the course of adjuvant therapy.

Mammary analogue secretory carcinoma (MASC) of parotid gland- A case report

Mammary analogue secretory carcinoma is a rare salivary gland carcinoma which shares morphologic and immunohistochemical features with the secretory carcinoma of breast and was first proposed by Skalova in 2010 with translocation of (q13; q25), t (12; 15), subsequently giving ETV6-NTRK3 gene rearrangement. Usually, it is a benign tumor that affects the parotid gland, with slight predilection for males. The present article report a case of secretory carcinoma of right parotid gland with special emphasis on histological feature and immunohistochemistry for diagnostic purpose and its management. Differential diagnosis includes AciCC, ADC-NOS and MEC. In a review by Chiosa et al (2012) in 337 cases of salivary gland malignancy included AciCC, ADC-NOS, MEC, LGCC, non-ITAC, signet ring adenocarcinoma, PLGA and most common malignancy reclassified as MASC were AciCC (11/89), ADC-NOS (14/37), MEC (1/165). Management for MASC includes surgical excision of the lesion (either superficial or total parotidectomy) for local, less aggressive disease like for low-grade malignant salivary gland neoplasms. For more invasive, metastatic disease and positive margins- neck dissection, radiotherapy and chemotherapy are reserved. There is no standard multidisciplinary treatment protocol established due to scarcity of this disease.

Primary Signet Ring Cell Mucinous Adenocarcinoma of the Urinary Bladder: A Rare Case Report

Primary ‘signet ring mucinous adenocarcinoma’ is most commonly located in the stomach. The bladder is an uncommon presentation site for the primary location of this tumor. Mucinous signet-ring adenocarcinoma with urinary bladder as the primary origin is uncommon, accounting for fewer than two percent of all upper urinary tract carcinomas. The presence of signet ring cells, which is caused by compression and displaced nucleus of the cell into a crescent placed in the periphery along the cell wall, is a distinguishing feature of signet ring cell carcinoma. These cells are loaded with cytoplasmic mucus-containing vacuoles. Lower than one-third of primary bladder signet ring cell carcinoma cases show this gross morphology showing linitis plastica pattern with subepithelial infiltration without producing an exophytic mass in a pure signet ring cell carcinoma. Because this tumor shares histological features with the adenocarcinomas originating in several other sites, such as the prostate, digestive tract, and reproductive system, immunohistochemistry tests are required to confirm the bladder as the primary origin. Owing to the paucity of the neoplasm and the difficulty in locating the underlying tumor, site identification is frequently prolonged, leaving palliative care as the only choice for roughly half of the patients. This study depicts a rare case report of primary vesicular signet ring cell mucinous adenocarcinoma that considerably invades the pelvis and retroperitoneum's prostate and lymph nodes. This case emphasizes the significant characteristics of bladder mucinous adenocarcinoma, such as the sequence of tumor spread, the propensity for preliminary diagnostic errors, the microscopic pattern, and the significance of immunohistochemistry for defining its primary root from the bladder and selecting the most suitable intervention from the start.

Goblet cell tumors of the appendix: Clinical and molecular features.

223 Background: Goblet Cell tumors (GCTs) of the appendix are a rare, distinct, and under studied malignancy. Since 2019 the preferred World Health Organization (WHO) terminology is Goblet Cell Adenocarcinoma (GCA), but previously many terms have been used to describe these tumors including Goblet Cell Carcinoid and Adenocarcinoma ex goblet cell carcinoid as these tumors have a histological appearance that blends neuroendocrine and adenocarcinoma features. Historically goblet cell tumors have been considered one of the more aggressive subtypes of appendiceal cancer, but limited data exists and is mostly in the form of case reports. Here we present the retrospective analysis of a large single institution cohort. Methods: The internal database of the University of Texas MD Anderson Cancer Center (MDACC) was queried to identify all patients diagnosed with goblet cell appendiceal tumor. Patients were classified to two different histopathological groups, GCA (n=220) and GCA with signet ring adenocarcinoma (SRA) (n=146). Clinical, histopathological, and molecular data were extracted from the database in semi-automated fashion. Survival analysis were performed using Kaplan Meier methodology. Results: 366 patients with GCTs were identified from 1986 to 2022. 132 (36%) patients were seen during the last five years, with an average of 26 patients per year. Median follow up time was 54 months, while median age at diagnosis was 57 years. Tumor grade data was available for 294 patients. 95% of the patients had high grade tumors (moderately, moderately to poorly and poorly-differentiated) (n= 278), and 5% had low grade tumors (well and well to moderately-differentiated (n=16). The median overall survival was 85 months, and significantly different between the two groups, 118 months for the GCA group and 57 months for the GCA with SRA (p= 0.003). Lymph node (LN) status was known for 168 patients, rate of LN involvement was 53% (n=89) and significantly different between the two groups with 41% (n=39) for GCA and 68% (n=50) for GCA with SRA (p= <0.0006). The internal database of MDACC was queried for LN status of Mucinous adenocarcinoma (MA) (n=242) and SRA (n=104) for comparison purposes, rate of LN positivity was 13% in MA and 76% in SRA. Node positive patients had significantly worse overall survival with median overall survival of 51 months vs 85 months for node negative patients (p<0.004). By multivariate analysis, both LN status and SRA component were independent predictors of overall survival. 107 patients had gene mutation analysis tested, TP53, SMAD4, GNAS and KRAS were the most commonly mutated with 13%, 9%, 4%, and 3% respectively. Conclusions: This study highlights the heterogenicity of GCTs of the appendix and the importance of the histopathological classification in this distinct entity. GCT are much more likely to spread to LN and have a distinct somatic mutation profile relative to MA.

Early Onset Colorectal Cancer in Arabs, Are We Dealing with a Distinct Disease?

Early-onset colorectal cancer (EOCRC) incidence is increasing worldwide. Efforts are directed to understand the biological and clinical signatures of EOCRC compared to late-onset colorectal cancer (LOCRC). EOCRC is thought to present differently across different ethnic groups and geographical regions. This study was an attempt to contribute with data from the Arab world toward the understanding of the clinicopathological parameters of EOCRC compared to LOCRC. Data from 254 CRC patients diagnosed at Sultan Qaboos University Hospital from the period 2015-2020 were studied. About 32.6% of all diagnosed CRC patients are below 50 years old, with no differences in gender distribution between EOCRC and LOCRC (p-value 0.417). Rectal involvement and tumor laterality were comparable among the two groups. Adenocarcinoma accounts for 83.3% and 94.2% of EOCRC and LOCRC, respectively. More mucinous and signet ring adenocarcinoma (8.3% each) were reported in EOCRC than LOCRC (2.9% and 2.2%, respectively). MLH1 and PMS2 loss are more common among LOCRC, but MSH6 loss is more frequent in EOCRC. The overall survival of EOCRC and LOCRC was comparable (median survival 64.88 and 67.24 months, respectively). This study showed comparable clinicopathological parameters between EOCRC and LOCRC from Arabs, which adds to the bigger picture of understand the disease.

P843 Mucinous and signet-ring colonic adenocarcinoma in Inflammatory Bowel Disease

Abstract Background Colorectal cancer (CRC) risk is increased in patients (pts) with long-standing colitis related to Inflammatory Bowel Disease (IBD). A higher frequency mucinous and signet-ring colonic adenocarcinoma has been suggested in IBD, but data regarding risk factors for these aggressive CRC are currently lacking. Primary aim was to assess the frequency of mucinous and signet-ring adenocarcinoma in IBD pts with CRC. Secondary aim was to assess risk factors for these histotypes of CRC. Methods From January 2002 to July 2022, all IBD pts with concomitant CRC were retrospectively enrolled. Inclusion criteria: 1) age ≥18; 2) well-defined diagnosis of IBD and CRC; 3) available histological and surgical report. Exclusion criteria: Missing data. Characteristics of IBD were reported according to standard criteria. Data were expressed as median [range]. Student-t Test and χ2 test were used for comparisons. Univariate logistic regression model was applied for assessing risk factors for mucinous and signet-ring adenocarcinoma (OR [95%CI]). Results The study population included 40 IBD pts with concomitant CRC: 24 (60%) with Ulcerative Colitis (UC) and 16 (40%) with Crohn’s Disease (CD). CRC included standard adenocarcinoma in 23 (57.5%) and mucinous or signet-ring in 17 (42.5%) pts. CD was more frequently stricturing in pts with standard adenocarcinoma (7 [77.8%] vs 1 [14.4%], p=0.04). CRC most frequently involved the rectum in pts with mucinous or signet-ring adenocarcinoma vs standard adenocarcinoma (4 [17.4%] vs 8 [47.1%]; p=0.04). Other IBD characteristics did not differ between standard and mucinous or signet-ring adenocarcinoma, including: age at CRC diagnosis (61 [30-80] vs 53 [29.80]; p=0.61), gender (F): 8 [34.8%] vs 5 [29.4%]; p=0.98), IBD duration at CRC diagnosis (14 [1-45] vs 17 [1-36]; p=0.74), smoking status (p=0.78), IBD type (UC: 14 [60.9%] vs 9 [56.3%]; p=0.84), UC extent and CD localization, frequency of perianal disease (p=0.37), thiopurine (p=0.55) or biologic (p=0.55) use. The proportion of pts surgically treated for CRC (20 [86.9%] vs 17 [100%], p=0.34) and the frequency of CRC-related death (3 [13.1%] vs 5 [29.4%]; p=0.37) were also comparable between groups. At diagnosis, CRC stage was comparable between pts with standard vs mucinous or signet-ring adenocarcinoma (stage I: 6 [26.1%] vs 1 [5.9%]; p=0.21; II: 9 [39.1%] vs 4 [23.5%]; p=0.48; III: 5 [21.7%] vs 7 [41.2%]; p=0.34); IV: 3 [13.1%] vs 2 [11.8%]; p=0.71). At univariate analysis, no specific risk factors for mucinous and signet-ring colonic adenocarcinoma were detected. Conclusion In the tested cohort of IBD patients with CRC, mucinous and signet-ring adenocarcinomas were observed in almost half of cases, although no specific risk factors were identified.

S3710 A Case Series of Gastric Adenocarcinoma Presenting as Cardiac Tamponade

Introduction: Gastric cancer is the fourth most common type of cancer worldwide and frequently presents at an advanced stage. As such, the presenting symptoms of gastric cancer may be related to sites of metastasis rather than the primary tumor. We describe two cases that presented to the same hospital within a six-month period who were found to have pericardial tamponade secondary to gastric adenocarcinoma metastasis. Case Description/Methods: Case 1 describes a case of a 91-year-old male who presented with progressively worsening dyspnea. A bedside echocardiogram revealed large pericardial effusion with evidence of cardiac tamponade. Pericardiocentesis and formation of a pericardial window was emergently performed. Cytology revealed metastatic signet ring adenocarcinoma with gastric as the most likely origin. Case 2 describes a case of a 68-year-old female with a history of breast cancer who presented to the hospital with epigastric pain, nausea and dyspnea on exertion accompanied by chest pain upon presentation to the ED. An echocardiogram revealed a large pericardial effusion with evidence of tamponade and a pericardiocentesis was urgently performed. A CT scan noted multiple hepatic lesions that were highly suspicious for metastatic disease. She underwent interventional radiology (IR) guided biopsy of a liver lesion and the pathology was consistent with adenocarcinoma. A follow-up esophagogastroduodenoscopy (EGD) with biopsies revealed moderately to poorly differentiated gastric adenocarcinoma as the primary tumor. Discussion: The pericardium is a rare site of metastasis for gastric adenocarcinoma and may present atypically. Subacute presentation of tamponade may mimic heart failure; thus physicians should have a lower threshold for ordering echocardiography.

S2046 High-Grade Mucinous Adenocarcinoma of the Appendix With Signet Features and Omental Metastasis

Introduction: Primary adenocarcinoma of the appendix is an uncommon malignancy of the gastrointestinal tract. It was first described in 1882 and constitutes around 0.12 to 2.6 cases per one million people per year. In addition, signet-ring cell carcinoma of the appendix is extremely rare, it constitutes approximately 4% of all primary appendiceal neoplasms. There are few reported cases of primary signet cell appendiceal carcinoma. In this present report, we describe a rare case of primary signet ring cell carcinoma of the appendix with omental metastases in an 81-year-old male who underwent laparoscopic appendectomy. Case Description/Methods: We present a case of an 81-year-old male who had prior negative esophagogastroduodenoscopy (EGD) and colonoscopy in 2017 who presented to an urgent care in January 2021 with abdominal pain. Lab work was unremarkable, and the patient was sent home with instructions to visit the emergency department (ED) if he experienced fever, increased abdominal pain, or blood in the stool. Patient presented to the emergency department with increased abdominal pain in April 2021, and Computed Tomography (CT) scan of abdomen and pelvis with intravenous contrast showed a cystic appendiceal lesion with right peritoneal nodularity suspicious for peritoneal carcinomatosis. Therefore, the patient underwent appendectomy the following day revealing poorly differentiated, high-grade appendiceal adenocarcinoma with signet ring features, pT4a disease. Patient had a diagnostic laparoscopy in June 2021 and was found to have diffuse peritoneal carcinomatosis. Multiple biopsies were obtained and came back positive with high-grade mucinous adenocarcinoma with signet ring features. Patient agreed to pursue systemic chemotherapy. He was initiated on Capecitabine (Xeloda) 2000 mg tab PO, twice daily for 14 days and off for 7 days. Bevacizumab (Avastin) 7.5 mg IV infusion every 3 weeks (Figure). Discussion: Patients with appendiceal neoplasms may have vague lower abdominal pain but are usually asymptomatic with incidental diagnosis on imaging or appendectomy. Signet ring adenocarcinoma of the appendix typically secretes mucin leading to metastasis throughout the peritoneum and eventual obstruction. Treatment is based on stage and histology. Surgical resection and peritoneal debulking is possible. High-grade tumors require further prospective trials to evaluate treatment, but treatment options include surgical management, HIPEC, and systemic chemotherapy.Figure 1.: Histologic examination showing a signet cell carcinoma of the appendix infiltrating the peritoneum and diaphragm. (A) right lower quadrant peritoneum biopsy, (H&E stain 100x): High grade mucinous carcinoma peritonei with signet ring cells. Pool of mucin with a cluster of epithelium that shows signs of metastatic carcinoma (enlarged nuclei, atypia, pleomorphic changes). (B, C, and D) Right diaphragm peritoneum biopsy. High grade mucinous carcinoma peritonei with signet ring cells. Image B at 100x, C at 200x, and D at 400x. (E & F) immunohistochemical cytokeratin stain (AE1/AE3) shows strong positivity of high grade carcinoma. E at 100x, and F at 400x.

S3566 Birthing a Baby or Surfacing a Hidden Tumor?

Introduction: Malignancy is a rare finding during pregnancy and if present, often carries poor prognosis. We present to you a case of Krukenberg tumor- a metastatic malignancy of the ovary- in a 29 year old female. Case Description/Methods: A 29-year-old female with no past medical history, presented to the hospital with preterm labor at 30 weeks gestation which lead to low transverse caesarian delivery secondary to recurrent prolonged decelerations and preterm contractions. Patient had an uneventful pregnancy course until this hospitalization. Intraoperatively, a large right sided ovarian mass was discovered. Tissue pathology revealed metastatic poorly differentiated adenocarcinoma. CT scan of the abdomen pelvis was suggestive of right adnexal mass measuring 10 × 14 × 13 cm with increased vascularity, large degree of abdominal pelvic ascites, with few lymph nodes in the upper mesenteric arcade, along with moderate thickening of the gastric wall. Esophagogastroduodenoscopy (EGD) revealed a gastric mass at cardia (Figure a), and tissue pathology was consistent with adenocarcinoma with presence of signet ring cells (Figure b). Additional work up was positive for elevated CA 125 and AFP tumor marker measuring 355 U/ml and 10.8 U/ml, respectively. Subsequent follow up with CT abdomen revealed bilateral ovarian metastasis with large volume ascites. Diagnostic paracentesis was negative for malignant ascites. Clinical course was complicated by recurrent ascites and progressive clinical deterioration. Due to poor performance status, the patient did not undergo any surgical intervention. Patient is currently being managed with palliative chemotherapy and paracentesis for symptomatic relief. Discussion: Krukenberg tumor is a metastatic malignancy of the ovary which is characterized by mucin-rich signet-ring adenocarcinoma that arises primarily from a gastrointestinal site. It accounts for almost 1%–2% of all ovarian tumors. The incidence of gastric cancer in the women of reproductive age group is 0.4%–0.5%, making these tumors extremely rare during pregnancy. Pregnancy symptoms masks the presence of the disease leading to diagnosis at a later stage. Unfortunately, no optimal treatment strategy for these tumors have been identified so far. Chemotherapy as well as radiation therapy does not seem to have any significant role in the prognosis of these patients. Due to metastatic nature and lower rate of resectability, surgery is deferred as it does not offer any increased survival time. The overall prognosis remains poor.Figure 1.: (a) EGD revealing gastric mass at cardia (b) Tissue pathology showing adenocarcinoma with presence of signet ring cells.

222. ARE GASTRIC MAPPING BIOPSIES NECESSARY TO DETERMINE THE DISTAL RESECTION MARGIN FOR SIGNET RING ADENOCARCINOMAS OF THE OESOPHAGO-GASTRIC JUNCTION?

Abstract In our department patients with oesophago-gastric junctional adenocarcinomas with signet ring differentiation undergo a second endoscopy for gastric mapping biopsies to investigate the extent of tumour extension into the proximal stomach. This is due to the perceived aggressive morphology and to avoid a R1 (microscopic positive) resection at the distal margin. Our aim was to elucidate whether gastric mapping endoscopic biopsies are necessary prior to resection in signet ring adenocarcinomas of the oesophago-gastric junction (OGJ). Patients with operable OGJ adenocarcinomas with signet ring morphology were retrospectively analysed from 2011–2021 from our databank of completed oesophagectomies at our upper gastrointestinal cancer surgical department. From 2014–2021, OGJ adenocarcinomas identified with signet ring differentiation were subjected to a second invasive endoscopy with gastric mapping biopsies to determine the distal ex-tent of microscopic invasion into the cardia and beyond. These were analysed to determine the histopathological yield from gastric mapping biopsies and the number of cases with a positive (R1) distal resection margin. From 2014, 322 oesophagectomy cases were completed and these were analysed further. Of these, 21.7% (n = 70) were found pre-operatively to have signet ring differentiation and thus underwent a second gastric mapping endoscopy. Within the signet ring morphology cohort, only one patient (1.4%) was found to involve a R1 resection margin which necessitated a second operation involving gastric resection and colonic interposition. Our results suggest that patients with signet ring adenocarcinoma of the OGJ do not need gastric mapping biopsies to determine the distal margin prior to resection. Although considered a more aggressive subtype of adenocarcinoma, radial infiltration from the tumour does not seem to affect conventional surgical oncological margins.

Development and validation of artificial intelligence models for preoperative prediction of inferior mesenteric artery lymph nodes metastasis in left colon and rectal cancer

BackgroundDissection of lymph nodes at the roots of the inferior mesenteric artery (IMAN) should be offered only to selected patients at a major risk of developing IMAN involvement. The aim of this study is to present the first artificial intelligence (AI) models to predict IMAN metastasis risk in the left colon and rectal cancer patients. MethodsA total of 2891 patients with descending colon including splenic flexure, sigmoid colon and rectal cancer undergoing major primary surgery and IMAN dissection were included as a study cohort, which was then split into a training set (67%) and a testing set (33%). Feature selection was conducted using the least absolute shrinkage and selection operator (LASSO) regression model. Seven AI algorithms, namely Support Vector Machine (SVM), Logistic Regression (LR), Extreme Gradient Boosting (XGB), Light Gradient Boosting (LGB), Decision Tree Classifier (DTC), Random Forest (RF) classifier, and Multilayer Perceptron (MLP), as well as traditional multivariate LR model were employed to construct predictive models. The optimal hyperparameters were determined with 5 fold cross-validation. The predictive performance of models and the expert surgeon was assessed and compared in the testing set independently. ResultsThe IMAN involvement incidence was 4.6%. The optimal set of features selected by LASSO included 10 characteristics: neoadjuvant treatment, age, synchronous liver metastasis, synchronous lung metastasis, signet ring adenocarcinoma, neural invasion, lymphovascular invasion, CA199, endoscopic obstruction, T stage evaluated by MRI. The most accurate model derived from MLP showed excellent prediction power with area under the receiver operating characteristic curve (AUROC) of 0.873 and produced 81.0% recognition sensitivity and 82.5% specificity in the testing set independently. In contrast, the judgment of IMAN metastasis by expert surgeon yield rather imprecise and unreliable results with a significantly lower AUROC of 0.509. Additionally, the proposed MLP had the highest net benefits and the largest reduction of unnecessary IMAN dissection without the cost of additional involved IMAN missed. ConclusionMLP model was able to maintain its prediction accuracy in the testing set better than other models and expert surgeons. Our MLP model could be used to help identify IMA nodal metastasis and to select candidates for individual IMAN dissection.

Signet-ring cells in pleural and peritoneal effusions identified on Wright stains – A diagnostic pitfall

Objectives:Signet-ring cells (SRCs) in effusion specimens represent a diagnostic challenge. In this study, a consecutive series of pleural and peritoneal effusions with benign SRCs are examined and compared with malignant SRCs.Material and Methods:We reviewed consecutive Wright-stained serous effusion slides and searched for cases with SRCs. Corresponding ThinPrep slides and clinical histories were reviewed. Cytology cases with known signet-ring adenocarcinoma were retrieved and reviewed.Results:Four hundred Wright-stained serous effusions were reviewed. Eighteen cases were identified with SRC-like cells. Thirteen patients had liver cirrhosis, three patients had end-stage renal disease, one patient had a history of pancreatic adenocarcinoma, and one patient had endometrioid carcinoma. For the latter two patients, the primary tumor showed no histologic findings of signet-ring features. In all cases, no SRCs were found on the corresponding ThinPrep slides. Five cytology cases with malignant SRCs were reviewed. Benign SRCs have a uniformly pale and markedly distended cytoplasm, and the nuclei are thin and curved. The malignant SRCs showed larger non-curved nuclei and bubbly mucin-containing cytoplasm.Conclusion:Mesothelial cells and histiocytes can mimic signet-ring adenocarcinoma cells on Wright-stained slides. Correlation with ThinPrep specimens is necessary before reporting, as the SRCs typically are not present in ThinPrep preparations.

Expression of CD10 and CD15 in colorectal mucinous and signet ring adenocarcinomas and its relation to clinicopathological features and prognosis.

CD10 and CD15 expression has been reported in several tumors. Whether CD10 and CD15 have a role in colorectal mucinous and signet ring adenocarcinoma (MSA) tumorigenesis is not yet known. We aimed to investigate the role of CD10 and CD15 expression in mucinous colorectal adenoma-carcinoma sequence (ACS) and determine if there is any clinical and prognostic significance associated with their expression. Seventy-five cases of colorectal MSA, and 9 cases of adenoma samples were collected. Manual TMA blocks were constructed and immunohistochemistry for CD10 and CD15 was done. Compared to adenomas, CD15 expression was significantly higher in MSA (p= 0.002), in contrast to CD10 expression. CD15 positivity was significantly associated with microsatellite stable (MSS) tumors (p= 0.018). The association between CD10 positivity and fungating tumor growth showed marginal significance. Unlike CD10, CD15 positivity showed significant association with overall survival of colorectal MSA patients. CD15 expression seems to have a role in mucinous colorectal ACS, with significant impact on the survival of MSA patients. Further studies are suggested to identify any genetic alterations that may underlie a potential association with disease progression.