Gastric and small bowel metastases from lung adenocarcinoma: A case report.

RATIONALE: Metastatic tumors in the stomach and small bowel are rare. This article reports a case of lung adenocarcinoma metastasizing to the stomach and small bowel. PATIENT CONCERNS: This case study presents the medical history of a 41-year-old male construction worker with a 1-month-long cough and slight chest discomfort. Imaging revealed a tumor in the right middle lobe of the lung, with metastasis to lymph nodes in the mediastinum and right hilar region, as well as a mass in the stomach's greater curvature and multiple lymph node metastases in the abdomen. Thirty-five days after the initial consultation, the patient exhibited worsening symptoms of vomiting and melena. A follow-up computed tomography scan revealed small bowel metastasis, leading to secondary intestinal obstruction and intussusception. DIAGNOSES: Biopsies confirmed poorly differentiated adenocarcinoma in the lung and stomach, with immunohistochemistry supporting a diagnosis of lung adenocarcinoma. Genetic testing showed no mutations or amplification in various genes. INTERVENTIONS: The patient received interventional hemostatic treatment; however, the efficacy of the intervention was poor. OUTCOMES: The patient experienced worsening gastrointestinal symptoms. Despite attempted intervention, the patient ultimately died 78 days after seeking medical attention. LESSONS: The case of lung cancer metastasizing to the stomach and small bowel presented in this article demonstrates high invasiveness and rapid progression. Combined with literature reports, this type of metastasis often indicates a poor prognosis for patients. The long-term benefits of surgical resection remain unclear, and further analysis will be needed with more cases and data in the future.

A case of completely resected cecum cancer with synchronous metastases to the small intestine found in acute appendicitis.

PURPOSE: Risk of malignant tumors increase with age;hence, careful examination of older patients should be consdiered when identifying the causes of acute appendicitis. Here, we report a case of a patient with cecum cancer with synchronous metastases to the small intestine that was found during acute appendicitis. CASE REPORT: A 74-year-old man presented with right lower abdominal pain. Physical examination revealed deep tenderness at McBurney's point. Enhanced computed tomography scan showed an abscess around the enlarged appendix and a thickened cecum wall. Colonoscopy revealed a type 2 tumor in the ileocecal region, and pathological examination of the biopsied specimen revealed adenocarcinoma. Microscopic findings revealed two type 2 tumors in the small intestine, pathologically diagnosed as cecum cancer metastases. The final diagnosis was acute appendicitis caused by cecum cancer with synchronous metastases to the small intestine, pStage ⅣB pT4bN1aM1b. The patient received adjuvant chemotherapy and has currently been disease-free for 24 months. CONCLUSIONS: In prolonged appendicitis among older adults, the possibility of malignancy should be considered during preoperative examination and prior to selecting a treatment plan. Delays in the diagnosis of colorectal cancer and metastases may lead to missed opportunities for complete resection and poor prognosis. J. Med. Invest. 71 : 293-297, August, 2024.

Metastatic Intestinal Adenocarcinoma: A Rare Case Involving the Mandible.

BACKGROUND: Metastatic intestinal adenocarcinoma involving the mandible is rare, posing diagnostic challenges because of its unusual presentation. CASE PRESENTATION: A 55-year-old male presented with a rapidly growing mass in the right mandible, accompanied by facial asymmetry and vestibular obliteration. Histopathological examinations revealed features consistent with adenocarcinoma. Immunohistochemical analysis supported the diagnosis of intestinal adenocarcinoma, with subsequent metastasis confirmed by PET scan findings. DIAGNOSIS: The lesion was conclusively diagnosed as intestinal adenocarcinoma metastasizing to the mandible. MANAGEMENT: The patient pursued treatment at a government facility, leading to a loss of follow-up.

Metastatic lung adenocarcinoma presenting with small bowel obstruction.

Lung cancer is one of the most lethal solid organ malignancies. Metastasis commonly spreads to the liver, adrenal glands and bone. We report a case of a male patient who presented with an 8 week history of cramping abdominal pain and vomiting. Subsequent investigation revealed evidence of an obstructing small bowel lesion. He underwent a small bowel resection. Histopathology revealed evidence of lung adenocarcinoma as the likely primary disease. Although metastasis of lung adenocarcinoma to the small bowel is rare, early recognition may prevent potentially life-threatening sequelae including bowel perforation and peritonitis.

Primary Lung Squamous Cell Carcinoma With Intestinal Metastasis: A Case Report and Literature Review.

Lung squamous cell carcinoma (LUSC) is characterized by a high rate of metastasis and recurrence, leading to a poor prognosis for affected patients. Intestinal metastasis of LUSC is a rare clinical occurrence. Treatment options for LUSC patients with intestinal metastasis are limited, and no standard therapy guidelines exist for managing these cases. In this review, we discuss the clinical features, diagnosis, and treatment of LUSC patients with intestinal metastasis and present a rare case of LUSC with intestinal metastasis. We describe a patient who presented with a severe cough and chest pain and diagnosed with LUSC and bone tumor. Initially, the primary LUSC and bone tumor were controlled with standard treatments. However, the primary LUSC reoccurred shortly after treatment, this time with intestinal metastasis, for which effective treatments are lacking. Our observation from the case suggests that LUSC metastasizing to intestinal tract is associated with a poorer prognosis.

A case of malignant melanoma of the small intestine with cardiac metastasis.

Malignant melanoma (MM) is notorious for its high metastatic potential, with cardiac metastasis being particularly severe as it involves cardiac structures and can lead to significant cardiac functional issues. While there is no standardized treatment approach, early detection and intervention can improve prognosis.

[A Case of Five Years Recurrence-Free Survival after Successful Multidisciplinary Treatment for Simultaneous Brain Metastasis and Heterochronic Small Intestinal Metastasis from Lung Cancer].

The patient was a 54-year-old male at the time of initial examination. He was aware of numbness and weakness in the left hemisphere of his body and came to see the hospital. He was diagnosed with brain metastasis of lung cancer and started treatment(cT2N0M1[Brain]). He underwent gamma knife for the head lesion and nivolumab for the lung lesion. The patient's lesions shrank with the success of the medical treatment, but recurred with small intestinal metastasis. He underwent a partial resection of the small intestine and was treated again with nivolumab, which resulted in a complete response. He is currently alive without recurrence. We have experienced a very rare case of recurrence-free survival after treatment for brain metastasis and small intestinal metastasis of lung cancer.

Value of Surgical Cytoreduction in Patients with Small Intestinal Neuroendocrine Tumors Metastatic to the Liver and Peritoneum.

BACKGROUND: Cytoreductive hepatectomy can improve survival and symptoms of hormonal excess in patients with small intestinal neuroendocrine tumor (siNET) liver metastases, but whether to proceed when peritoneal metastases are encountered at the time of planned cytoreductive hepatectomy is controversial. METHODS: This was a retrospective review of patients who underwent surgical management of metastatic siNETs at Mayo Clinic between 2000 and 2020. Patients who underwent cytoreductive operation for isolated liver metastases or both liver and peritoneal metastases were compared. RESULTS: Of 261 patients who underwent cytoreductive operation for siNETs, 211 had isolated liver metastases and 50 had liver and peritoneal metastases. Complete cytoreduction was achieved in 78% of patients with isolated liver metastases and 56% of those with liver and peritoneal metastases (p = 0.002). After complete cytoreduction, median overall survival (OS) was 11.5 years for isolated liver metastases and 11.2 years for liver and peritoneal metastases (p = 0.10), and relief of carcinoid syndrome was ≥ 97% in both groups. After incomplete cytoreduction with debulking of > 90% of hepatic disease and/or closing Lyon score of 1-2, median OS was 6.4 years for isolated liver metastases and 7.1 years for liver and peritoneal metastases (p = 0.12). CONCLUSIONS: Patients with siNETs metastatic to both the liver and peritoneum have favorable outcomes after aggressive surgical cytoreduction, with the best outcomes observed after complete cytoreduction. Therefore, the presence of peritoneal metastases should not by itself preclude surgical cytoreduction in this population.

Melanoma metastásico en intestino delgado: causa infrecuente de perforación: reporte de caso / Metastatic melanoma in the small intestine: infrequent cause of perforation: case report / Melanoma metastático em intestino delgado: causa rara de perfuração: relato de caso

El intestino delgado es el sitio de asiento más frecuente del melanoma metastásico. Su diagnóstico es un desafío por cursar asintomático o con síntomas inespecíficos. Son pocos los casos que presentan complicaciones, siendo infrecuente la peritonitis por perforación. El objetivo del trabajo es comunicar el caso clínico de una peritonitis por perforación de una metástasis de melanoma en intestino delgado. Caso clínico: Paciente de sexo masculino de 66 años con diagnóstico de melanoma de cuello y secundario óseo, encefálico y pulmonar, fue intervenido de urgencia por peritonitis aguda por perforación de metástasis en intestino delgado. El estudio histológico confirmó secundarismo de melanoma cutáneo. Conclusión: Sabiendo que el yeyuno íleon es el sitio de asiento más frecuente de las metástasis de melanoma, ante la presencia de síntomas digestivos inespecíficos o anemia se debe sospechar su compromiso y evaluar posibles alternativas terapéuticas.

The small intestine is the most frequent site of metastatic melanoma. However, its diagnosis continues to be a challenge since it is usually asymptomatic or with non-specific symptoms. Few cases result in complications, peritonitis due to perforation being infrequent. The objective of the work is to report a clinical case of peritonitis due to perforation of a melanoma metastasis in the small intestine. Clinical case: A 66-year-old male patient diagnosed with melanoma of the neck and secondary bone, brain and lung melanoma, underwent emergency surgery for acute peritonitis due to perforation of metastasis in the small intestine, which was resected and anastomosed. The histology confirmed the secondary nature of the cutaneous melanoma. Conclusion: Knowing that the jejunum-ileum is the most frequent site of melanoma metastases, in the presence of non-specific digestive symptoms or anemia, its involvement should be suspected and possible therapeutic alternatives should be evaluated.

O intestino delgado é o local mais frequente de melanoma metastático. O diagnóstico é um desafio por ser assintomático ou apresentar sintomas inespecíficos. Há poucos casos que apresentam complicações, sendo pouco frequente a peritonite por perfuração. O objetivo deste trabalho é relatar um caso clínico de peritonite por perfuração de metástase de melanoma no intestino delgado. Caso clínico: Paciente do sexo masculino, 66 anos, diagnosticado com melanoma no pescoço com metástase óssea, cefálica e pulmonar. Foi submetido a cirurgia de emergência por peritonite aguda por perfuração de metástases do intestino delgado. O estudo histológico confirmou melanoma cutâneo. Conclusão: Sabendo que o jejuno e o íleo é o local mais frequente de metástase de melanoma, na presença de sintomas digestivos inespecíficos ou anemia deve-se suspeitar de seu acometimento e avaliar possíveis alternativas terapêuticas.

Small bowel metastases from a testicular choriocarcinoma revealed by gastrointestinal bleeding: a case report.

Testicular germ cell tumors are the most common cancers in young men. In most cases, patients may present a painless testicular swelling. However, in 10% the presentation is variable and related to site of metastasis and complications. Clinically apparent gastrointestinal involvement was seen in 5% of cases and dominates by gastrointestinal bleeding. We report a case of testicular choriocarcinoma involving the small intestine revealed by melena and complicated by acute intussusception.

A rare case report of malignant peripheral nerve sheath tumor involving both the small bowel and large bowel.

Malignant peripheral nerve sheath tumor (MPNST) contains properties and histologic markers of both neural crest cells and mesenchymal cells. It is a rare diagnosis, with an incidence of 1:100,000/year or 4%-10% of soft-tissue sarcomas. There are very few cases reported and studied. Therefore, establishing a proper diagnosis and treatment of MPNST provides a challenge. We present this unique and rare case of metastatic MPNST of the small and large bowel with bone, pulmonary, liver, and splenic metastases. The patient subsequently developed hemorrhagic brain metastases and died 6 months after THE initial diagnosis.

Résumé La tumeur maligne de la gaine nerveuse périphérique (MPNST) contient des propriétés et des marqueurs histologiques des cellules de la crête neurale et du mésenchyme cellules. Il s'agit d'un diagnostic rare, avec une incidence de 1: 100 000 / an ou 4 à 10% des sarcomes des tissus mous. Il y a très peu de cas signalés et étudié. Par conséquent, l'établissement d'un diagnostic et d'un traitement appropriés de la MPNST constitue un défi. Nous présentons ce cas unique et rare de MPNST métastatique du petit et du gros intestin avec métastases osseuses, pulmonaires, hépatiques et spléniques. Le patient a ensuite développé métastases cérébrales hémorragiques et est décédé 6 mois après LE diagnostic initial.

Recurrent and metastatic female adnexal tumor of probable Wolffian origin: A case report and review of the literature.

RATIONALE: Female adnexal tumors of probable Wolffian origin (FATWOs) are rare gynecologic neoplasms arising from the mesonephric duct remnants. Less than 90 cases have been reported in the English literature. Although most cases of FATWO are considered benign, recurrence and metastasis may occur in very few cases during the course of the disease. Due to the small number of recurrent and metastatic FATWO cases, there are no clear recommendations regarding optimal treatment. PATIENT CONCERNS: A 75-year-old postmenopausal woman, who underwent a mass excision of the right broad ligament three years ago, was found to have a right adnexal mass during a regular postoperative physical examination. DIAGNOSES: Vaginal ultrasound examination revealed a cystic and solid mass approximately 3.6 × 4.4 × 3.8 cm on the right side of the uterus. Three years ago, the mass of the right broad ligament was diagnosed with FATWO in the local hospital. Following extensive immunohistochemistry analysis and after reviewing the histology slides from the primary tumor, the final diagnosis of the mass on the right side of the uterus was recurrent and metastatic FATWO. INTERVENTIONS: The patient underwent laparoscopic mass excision, hysterectomy and resection of the metastatic lesion in the small intestine, and then she received 6 cycles of docetaxel and carboplatin-based chemotherapy. OUTCOMES: The disease has recurred three years after the first surgery in the local hospital. After the second surgery followed by systemic chemotherapy, there is no evidence of recurrence with 24 months of follow-up till now. LESSONS: FATWO is considered a benign entity. However, a few FATWOs have been shown to behave aggressively. Due to only a few reported cases, there are no comprehensive recommendations regarding the optimal clinical management of recurrent and metastatic FATWOs. Complete surgical resection followed by combination chemotherapy is considered to be the most effective therapy for recurrent and metastatic FATWOs. Chemotherapy with docetaxel plus carboplatin, which is most commonly used in malignant cases, may be effective in the treatment of recurrent and metastatic FATWOs.

Coping with social consequences of disease-related symptoms in patients with a metastatic small intestinal neuroendocrine tumour: A qualitative study.

Patients with small intestine neuroendocrine tumours (SINETs) face various disease-related symptoms that can affect their social functioning and quality of life. The present study aimed to explore the social consequences of disease-related symptoms in patients with a metastatic SINET and to develop a theory on how these patients experience their disease. Patients were eligible when they were diagnosed with a metastatic SINET between 2009 and 2016 and were younger than 60 years of age during diagnosis, and had a good functional performance status. Semi-structured interviews were conducted between January and June 2018. Data were transcribed and analysed independently by two researchers using grounded theory. Data saturation was reached at 10 interviews and, in total, 12 patients participated. A core component that arose from the interviews was resilience in the face of social consequences of having a metastatic SINET. Prominent physical symptoms were fatigue, diarrhoea and flushes. All of these symptoms were associated with limitations to function in work-related and social activities, as well as feelings of embarrassment and shame. Adaptive strategies, such as careful planning, or focusing on the perspective to live well with a neuroendocrine tumour, helped patients to experience the consequences as less burdensome. Other helpful factors that were identified constituted social support, engaging in meaningful activities and financial stability. Patients with a metastatic SINET experienced social consequences of disease-related symptoms in daily life, although they were able to attenuate the burden of these consequences by using adaptive problem-based, emotion-based and meaning-based coping strategies. Clinicians could explore the perceived consequences and educate patients about adaptive strategies.

Ki-67 Labeling Index Variability Between Surgically Resected Primary and Metastatic Hepatic Lesions of Gastroenteropancreatic Neuroendocrine Neoplasms.

Background. A higher Ki-67 labeling index is associated with a poorer prognosis in gastroenteropancreatic neuroendocrine neoplasms. It has also been proposed that the Ki-67 labeling index may increase during disease progression from the primary site to metastatic sites. Although biopsy specimens are used to measure the Ki-67 labeling index, heterogeneity in lesions is thought to affect the assessment of the Ki-67 labeling index. To overcome tumor heterogeneity, we evaluated the variability in the Ki-67 labeling index between primary lesions and hepatic metastases by analyzing only surgically resected specimens. Methods. We conducted a single-center retrospective study to analyze the variability in the Ki-67 labeling index and the change in tumor grade between the primary site and metastatic hepatic sites in 19 patients diagnosed with gastroenteropancreatic neuroendocrine neoplasms at the Cancer Institute Hospital of the Japanese Foundation for Cancer Research from 1998 to 2018. Both the primary site and metastatic hepatic sites were surgically resected. Results. Among the 19 patients with gastroenteropancreatic neuroendocrine neoplasms, 12 patients (63%) showed higher levels of the Ki-67 labeling index at metastatic hepatic sites than at the primary site. The median Ki-67 labeling index levels for the primary lesion and metastatic hepatic lesions were 5% and 10%, respectively. The Ki-67 labeling index levels were significantly elevated in the metastatic hepatic lesions compared to the primary lesion (P = .002). Conclusions. This study addressed the heterogeneity of the Ki-67 labeling index by analyzing only surgically resected specimens. We observed a statistically significant increase in the Ki-67 labeling index in hepatic metastases compared to the primary lesion.

Undifferentiated large cell/rhabdoid carcinoma presenting in the intestines of patients with concurrent or recent non-small cell lung cancer (NSCLC): clinicopathologic and molecular analysis of 14 cases indicates an unusual pattern of dedifferentiated metastases.

Undifferentiated carcinoma metastatic to the bowel is uncommon in surgical pathology practice and might be confused with primary gastrointestinal carcinoma, melanoma, lymphoma, and others. We present 14 cases of uni- (n = 9) or multifocal (n = 5) undifferentiated large cell/rhabdoid carcinoma presenting in the bowel of patients with concurrent (n = 9) or recent (diagnosed 1 to 25 months earlier; median, 4) non-small cell lung cancer (NSCLC). Patients were 6 females and 8 males, aged 52 to 85 years. Primary NSCLC was verified histologically in 10 cases and by imaging in 4. The undifferentiated histology was present in the lung biopsy in 4/10 patients (as sole pattern in 3 and combined with adenocarcinoma in 1) and was limited to the intestinal metastases in the remainder. PDL1 was strongly expressed in 7/9 cases (CPS: 41 to 100). Loss of at least one SWI/SNF subunit was detected in 7/13 cases (54%). SMARCA2 loss (n = 6) was most frequent and was combined with SMARCA4 loss in one case. PBRM1 loss was observed in one tumor. Successful molecular testing of 11 cases revealed BRAF mutations in 4 (3 were non-V600E variants), KRAS mutations in 3, and wildtype in 4. None had EGFR mutations. Analysis of 4 paired samples revealed concordant KRAS (2) and BRAF (1) mutations or wildtype (1). Our study indicates that undifferentiated carcinoma within the intestines of patients with concurrent/recent NSCLC represents dedifferentiated metastasis from the NSCLC. Recognition of this unusual presentation is cardinal to avoid misdiagnosis with inappropriate therapeutic and prognostic implications.

Response rates in metastatic neuroendocrine tumors receiving peptide receptor radionuclide therapy and implications for future treatment strategies.

BACKGROUND: Peptide receptor radionuclide therapy is a targeted therapy used to treat unresectable somatostatin receptor-positive neuroendocrine tumors. The objective of this study was to evaluate response rates among neuroendocrine tumors of different primaries and identify factors relevant to future treatment strategies. METHODS: We retrospectively reviewed patients who received peptide receptor radionuclide therapy for neuroendocrine tumors from 2018 to 2019 at our institution. Patients were assessed with computed tomography/magnetic resonance imaging and 68Ga-DOTATATE-positron emission tomography before and after 2 or 4 cycles of peptide receptor radionuclide therapy. Tumor response was evaluated by RECIST 1.1. Statistics included multinomial logistic regression models and Fisher exact test. RESULTS: Twenty-seven patients underwent 92 cycles of peptide receptor radionuclide therapy: pancreas (n = 11), small bowel (n = 7), and other (n = 9) neuroendocrine tumors. Overall, 30% (8 of 27) had partial response, 59% (16 of 27) stable disease, and 11% (3 of 27) progressed. Pancreatic neuroendocrine tumors responded differently from small bowel neuroendocrine tumors regardless of cycle number (P = .01). The majority of pancreatic neuroendocrine tumors (6 of 11) had partial response to peptide receptor radionuclide therapy, while all small bowel neuroendocrine tumors had stable disease. Pancreatic neuroendocrine tumors stable after 2 cycles were more likely to respond to additional cycles versus other neuroendocrine tumors (probability: 60% vs 11%). CONCLUSION: Patients with unresectable advanced or metastatic pancreatic neuroendocrine tumors may benefit from a full course of peptide receptor radionuclide therapy, whereas other neuroendocrine tumors appear less likely to respond. Large prospective studies are needed to confirm these findings.

Surgical treatment of melanoma metastases to the small bowel: A single cancer referral center real-life experience.

INTRODUCTION: Treatment of metastatic melanoma has rapidly changed during the last years, and patients often require a multidisciplinary approach to achieve effective results. We aimed to assess the survival benefit achieved through surgical approach to patients with small bowel (SB) metastases from cutaneous melanoma, to emphasize the potential role of surgery in association with novel therapies. METHODS: Ninety consecutive patients with cutaneous melanoma diagnosed as having resectable SB metastases from 1995 to 2015 were retrospectively investigated. RESULTS: Median age at surgery of melanoma metastases was 53.4 years. Among 30 patients who had a curative-intent resection, the 5- and 10-year survival rates were 61% and 54%, respectively, while among 60 patients treated with a palliative surgery the corresponding rates were both 4%. Among 29 patients, for whom the interval time between the occurrence of SB metastases and the previous surgical event on GI tract was ≥36 months, the 5-year overall survival rate was 42%; for 56 patients who had an interval time <36 months the corresponding survival rate was 14%. Within the whole series, an absence of any residual disease after surgery (R0) was a factor affecting better survival, regardless of the evidence of metastases in other organs. CONCLUSION: Our observational data showed that surgical treatment for patients with SB metastases from melanoma might increase survival, but further studies are needed to confirm this finding. In the age of novel available therapies, the increase in survival time given by surgery may offer important chances for patients to benefit from systemic therapies.

Positivity for SATB2 distinguishes Islet1 positive rectal neuroendocrine tumours from pancreaticoduodenal neuroendocrine tumours.

AIMS: Determining the site of origin of a metastatic neuroendocrine tumour (NET) can be challenging and has important prognostic and therapeutic implications. An immunohistochemical (IHC) panel consisting of TTF1, CDX2, PAX8/PAX6 and Islet1 is often employed. However, there can be a significant IHC overlap among different primary sites. Herein, we sought to determine the utility of including Special AT-rich sequence binding protein-2 (SATB2) in the IHC panel that is used for determining the site of origin of a metastatic NET. METHODS: Paraffin tissue microarrays consisting of 137 primary NETs (26 lung, 22 jejunoileal, 8 appendix, 5 stomach, 4 duodenum, 17 rectum and 55 pancreas) were stained for SATB2, in addition to the well-described lineage-associated markers, such as TTF1, CDX2, PAX6 and Islet1. Additionally, a tissue microarray consisting of 21 metastatic NETs (1 lung, 1 stomach, 8 jejunoileal and 11 pancreas) was stained for TTF1, CDX2, SATB2 and Islet1. The results were recorded as no staining, weak staining and moderate to strong staining. RESULTS: All appendiceal NETs and majority (88%) of the rectal NETs were positive for SATB2. All primary foregut NETs (stomach, pancreas, duodenum and lung) were negative for SATB2, except for one pulmonary NET with weak staining. However, among the metastatic tumours, 5 of 11 pancreatic NETs, 1 stomach NET, 1 lung NET and 2 of 8 jejunoileal NETs showed weak staining. Receiver operating characteristic analysis incorporating sensitivity and specificity data of IHC panel, considering moderate to strong staining as truly positive cases, showed that inclusion of SATB2 to the previously described NET IHC panel outperformed the panel without SATB2, raising the specificity for pancreaticoduodenal NETs from 81.2% to 100%, with a positive predictive value (PPV) of 100% and negative predictive value (NPV) of 82.22% (p<0.0001); for appendiceal NETs the specificity changed from 99.1% to 98.5% and sensitivity increased from 11.8% to 80%, with a PPV and NPV of 66.67% and 99.26%, respectively (p<0.0001); and for rectal NETs the specificity increased from 97.6% to 99.3% and sensitivity raised from 7.1% to 66.7%, with a PPV and NPV of 80% and 98.53%, respectively (p<0.0001). CONCLUSIONS: SATB2 stain is useful in differentiatingIslet1/PAX6 positive pancreatic and rectal NETs, as rectal NETs are typically moderately to strongly positive for SATB2 and pancreatic NETs are usually negative or weakly positive for SATB2. Moderate to strong staining for SATB2 is suggestive of an appendiceal or a rectal primary. SATB2 may complement the panel of CDX2, TTF1 and Islet1 in determining the site of origin of an NET in a metastatic setting.

Magnetic Resonance Imaging May Be Able to Identify the Origin of Neuroendocrine Tumor Liver Metastases.

OBJECTIVES: The aim of the study was to discriminate hepatic metastases from pancreatic neuroendocrine tumors (pNET) and hepatic metastases from midgut neuroendocrine tumors (mNET) with magnetic resonance imaging (MRI). METHODS: MRI examinations of 24 patients with hepatic metastases from pNET were quantitatively and qualitatively assessed by 2 blinded readers and compared to those obtained in 23 patients with hepatic metastases from mNET. Inter-reader agreement was calculated with kappa and intraclass correlation coefficient (ICC). Sensitivity, specificity, and accuracy of each variable for the diagnosis of hepatic metastasis from pNET were calculated. Associations between variables and primary tumor (i.e., pNET vs. mNET) were assessed by univariate and multivariate analyses. A nomogram was developed and validated using an external cohort of 20 patients with pNET and 20 patients with mNET. RESULTS: Interobserver agreement was strong to perfect (k = 0.893-1) for qualitative criteria and excellent for quantitative variables (ICC: 0.9817-0.9996). At univariate analysis, homogeneity on T1-weighted images was the most discriminating variable for the diagnosis of pNET (OR: 6.417; p = 0.013) with greatest sensitivity (88%; 21/24; 95% CI: 68-97%). At multivariate analysis, tumor homogeneity on T1-weighted images (p = 0.007; OR: 17.607; 95% CI: 2.179-142.295) and target sign on diffusion-weighted images (p = 0.007; OR: 19.869; 95% CI: 2.305-171.276) were independently associated with pNET. Nomogram yielded a corrected AUC of 0.894 (95% CI: 0.796-0.992) for the diagnosis of pNET in the training cohort and 0.805 (95% CI: 0.662-0.948) in the validation cohort. CONCLUSIONS: MRI provides qualitative features that can help discriminate between hepatic metastases from pNET and those from mNET.