Neuroendocrine Neoplasms in Rare Locations: Clinicopathological Features and Review of the Literature

Prediction of 177Lu-DOTATATE Therapy Outcomes in Neuroendocrine Tumor Patients Using Semi-Automatic Tumor Delineation on 68Ga-DOTATATE PET/CT

BACKGROUND

Treatment of metastatic neuroendocrine tumors (NET) with 177Lu-DOTATATE peptide receptor radionuclide therapy (PRRT) results in favorable response only in a subset of patients. We investigated the prognostic value of quantitative pre-treatment semi-automatic 68Ga-DOTATATE PET/CT analysis in NET patients treated with PRRT.

METHODS

The medical records of 94 NET patients who received at least one cycle of PRRT at a single institution were retrospectively reviewed. On each pre-treatment 68Ga-DOTATATE PET/CT, the total tumor volume (TTV), maximum tumor standardized uptake value for the patient (SUVmax), and average uptake in the lesion with the lowest radiotracer uptake (SUVmin) were determined with a semi-automatic tumor delineation method. Progression-free survival (PFS) and overall survival (OS) among the patients were compared based on optimal cutoff values for the imaging parameters.

RESULTS

On Kaplan-Meier analysis and univariate Cox regression, significantly shorter PFS was observed in patients with lower SUVmax, lower SUVmin, and higher TTV. On multivariate Cox regression, lower SUVmin and higher TTV remained predictive of shorter PFS. Only higher TTV was found to be predictive of shorter OS on Kaplan-Meier and Cox regression analyses. In a post hoc Kaplan-Meier analysis, patients with at least one high-risk feature (low SUVmin or high TTV) showed shorter PFS and OS, which may be the most convenient parameter to measure in clinical practice.

CONCLUSIONS

The tumor volume and lowest lesion uptake on 68Ga-DOTATATE PET/CT can predict disease progression following PRRT in NET patients, with the former also predictive of overall survival. NET patients at risk for poor outcomes following PRRT can be identified with semi-automated quantitative analysis of 68Ga-DOTATATE PET/CT.

Primary renal neuroendocrine neoplasms: A systematic literature review, report of four local cases, and original survival analysis of 63 patients from a national registry 2012-2018

Primary renal neuroendocrine neoplasms (NEN) are rare. We aimed to conduct a systematic review, present local cases, and analyse data from the England's National Cancer Registration and Analysis Service (NCRAS) to provide comprehensive evidence on clinical experience, incidence, and survival to better characterize these tumours. First, a systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) method; second, a synthesis of local cases; and, finally, a retrospective population-based cohort analysis of renal NEN recorded between 2012 and 2018 on NCRAS were performed. Kaplan-Meier estimator was used to calculate overall survival and Cox proportional hazard regression to identify prognostic factors. Systematic review identified 48 articles and the evidence was summarized and presented. We reported data from four local cases presenting with abdominal and back pain but without carcinoid syndrome. In population-based analysis, we identified 63 cases of renal NEN between 2012 and 2018 from the registry. Age-standardized incidence was 0.09-0.32 per million with a median age of 64 years (interquartile range = 48-72 years). Survival was worse in males and those aged 64 years and over. Five-year survival for renal neuroendocrine tumours (NET) was 69.8% (95% confidence interval = 66.6-72.7) and neuroendocrine carcinomas (NEC) was 38.4% (95% confidence interval = 34.6-42.0). No independent predictive factor was identified in the multivariable analyses. We have given a systematic review of evidence, published local experience, and reported incidence and survival of renal NEN in England for the first time. We have provided clinicians with evidence on diagnosis and proposed a treatment algorithm of theses rare tumours. The incidence and median age of presentation in England is similar to other published series. Renal NET has better survival than renal NEC as expected. A uniform classification system would reduce inconsistencies in reporting and standardize treatment decisions for this neoplasia.

Head to head: Do neuroendocrine tumours in the breast truly exist?

Breast cancer (BC) is a heterogeneous disease with a spectrum of morphological features. Concepts of histogenesis and differentiation in BC remain controversial. Recent evidence supports differentiation rather than histogenesis as the underlying mechanism for the myriad morphological appearances of BC. Prognosis and response to therapy are determined by a combination of factors including tumour grade, stage and receptor status whereas tumour histological types play an independent role in only limited examples. Neuroendocrine tumours (NETs) comprise one of the most debated entities in the breast since their first description. Apart from the rare small cell NE carcinoma (NEC) which has well-characterised features similar to their counterparts in other organs, the true existence, diagnostic criteria and clinical significance of NE neoplasms (NENs) in the breast are shrouded in controversy. At the core of this discussion is whether normal NE cells exist in the breast, and if breast NETs have distinct morphology and clinical behaviour. When NETs are encountered in the breast, metastatic origin has to be excluded. The more frequent situation in which NE differentiation is observed in breast cancers is in the context of recognisable, morphologically well described special type neoplasms like the hypercellular mucinous carcinoma and solid papillary carcinoma. In this review, arguments for and against maintaining the category of NENs in the breast are articulated in relation to existing literature on this group of unusual tumours.

Challenges in treatment of a patient suffering from neuroendocrine tumor G1 of the hilar bile duct: a case report

Background

Neuroendocrine tumors (NETs) arise from neuroendocrine cells and are extremely rare in the biliary tract. Currently, there are no guidelines for the diagnosis and treatment of biliary NETs. We presented a case with NETs G1 of the hilar bile duct and the challenges for her treatment.

Case presentation

A 24-year-old woman was presented to our department with painless jaundice and pruritus, and the preoperative diagnosis was Bismuth type II hilar cholangiocarcinoma. She underwent Roux-en-Y hepaticojejunostomy with excision of the extrahepatic biliary tree and radical lymphadenectomy. Unexpectedly, postoperative pathological and immunohistochemical examination indicated a perihilar bile duct NETs G1 with the microscopic invasion of the resected right hepatic duct. Then the patient received 3 cycles of adjuvant chemotherapy (Gemcitabine and tegafur-gimeracil-oteracil potassium capsule). At present, this patient has been following up for 24 months without recurrence or disease progression.

Conclusion

We know little of biliary NETs because of its rarity. There are currently no guidelines for the diagnosis and treatment of biliary NETs. We reported a case of perihilar bile duct NETs G1 with R1 resection, as far as we know this is the first report. More information about biliary NETs should be registered.

Comparison of Serum and Urinary 5-Hydroxyindoleacetic Acid as Biomarker for Neuroendocrine Neoplasms

CONTEXT

Patients with serotonin-secreting neuroendocrine neoplasms (NENs) have increased serum 5-hydroxyindoleacetic acid (5HIAA) concentrations. Serum 5HIAA thus serves as a biomarker in NEN.

OBJECTIVE

To evaluate an improved tandem mass spectrometric serum 5HIAA assay for diagnosis and follow-up of NEN in a clinical cohort.

DESIGN

A retrospective study during 2016-2018 at the Diagnostic Center and Department of Endocrinology at Helsinki University Hospital, Finland.

METHODS

Detailed patient data was obtained from 116 patients. Serum 5HIAA was analyzed by 2 different liquid chromatography with tandem mass spectrometry (LC-MS/MS) assays with samples prepared either by protein precipitation or solid phase extraction. Twenty-four-hour urine 5HIAA samples (n = 33) were analyzed by amperometric LC, and the results were compared. Specificity and sensitivity were calculated by receiver operating characteristic (ROC) analysis.

RESULTS

We achieved 5 to10 000 nmol/L linearity and ≤2.5% variation with our new serum 5HIAA assay. In ROC analysis, the area under curve was 85% by serum assays [upper reference limit (URL) value 123 nmol/L] and 88% by the 24-h urine 5HIAA assay (URL value of 47.1 µmol), respectively. A difference (P < 0.001) between patients with active NEN and patients in remission was found by all 5HIAA assays.

CONCLUSION

Serum 5HIAA by LC-MS/MS after protein precipitation performs equally well for the diagnosis of NEN as urinary 5HIAA LC assay. The outcome and sensitivity for serum and 24-h urine assays are convergent. Due to much more reliable and convenient sampling, we recommend serum instead of 24-h urine 5HIAA for diagnosis and follow-up of NEN patients.

Single institutional experience on primary neuroendocrine neoplasms of the kidney: a rare distinct entity

Primary pure renal neuroendocrine neoplasms (R-NENs) are a distinct and rare entity. Not much is known about the histopathology and biologic behavior of these tumors. We attempted to review the clinicopathologic aspects of these neoplasms encountered at our institution. We performed a retrospective chart review to identify primary pure (not admixed with any other tumor component) R-NENs from institutional Cancer Registry database. Pathologic review of the diagnostic archival slides was done for detailed assessment of the histologic features. R-NENs were classified according to the current WHO system for gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). Eight pure R-NEN cases were identified, all unifocal, and most (6/8) involved the right kidney. Three patients had poorly differentiated neuroendocrine carcinoma (NEC), and five had well-differentiated neuroendocrine tumor (NET). All tumors were located near the renal hilum, stained diffusely with synaptophysin, variably with chromogranin, and were negative for renal site-specific marker PAX8 or for markers of renal cell carcinoma. We identified two distinct patterns of growth: one of sheets with interspersed rosettes and the other of large nests with low proliferative crowded centers and peripheral cells with higher proliferation and prominent palisading. Based on Ki-67 proliferative index, the tumors were classifiable into WHO grade 1 or grade 2 (based on GEP-NEN). All three NECs characteristically showed cytologic features intermediate between classic large and small cell type. This is the first comprehensive clinicopathologic study involving the rare group of R-NEN. Classifying and grading them according to the GEP-NEN system is of prognostic significance.

High-grade Neuroendocrine Carcinomas of the Vulva: A Clinicopathologic Study of 16 Cases

Vulvar high-grade neuroendocrine carcinomas (HGNECs) are rare and primarily thought to represent Merkel cell carcinoma (MCC). We present the clinicopathologic features of 16 such cases, the largest series to date. Patients were most often White, postmenopausal, and symptomatic from a palpable vulvar mass/nodule. Tumors ranged from 0.7 to 6 cm and most commonly involved the labium majus. Majority of the cases were pure HGNECs (15/16) with small cell (SC) morphology (14/16); 2 were large cell neuroendocrine carcinomas, of which 1 was combined with moderately differentiated adenocarcinoma. All tumors expressed synaptophysin. Of the 14 HGNECs with SC morphology, 6 were CK20-positive MCCs with characteristic CAM5.2 and neurofilament (NF) expression. Five of these MCCs were positive for Merkel cell polyoma virus large T-antigen (MCPyVLTAg). In contrast, 6 HGNECs with SC morphology were negative for CK20, NF, and MCPyVLTAg and classified as SCNECs. High-risk human papilloma virus was positive in all SCNECs and negative in all MCCs. One case of HGNEC with SC morphology could not be entirely characterized due to lack of tissue for ancillary testing. Five of 12 (42%) cases had a discrepant diagnosis initially rendered. Most patients (10/15) presented with International Federation of Gynecology and Obstetrics stage III or IV disease. Usual sites of metastasis included inguinal lymph node, liver, bone, and lung. Twelve patients underwent surgery with adjuvant chemotherapy and/or radiation therapy, 1 received adjuvant immunotherapy, and 1 patient received neoadjuvant chemotherapy followed by surgery and adjuvant radiation therapy. Median overall survival was 24 months (range: 7 to 103 mo), and overall 5-year survival was 12% (95% confidence interval: 1% to 39%). In summary, vulvar HGNECs are rare, aggressive neoplasms that can be further subclassified into MCC, SCNEC, and large cell neuroendocrine carcinoma. CK20, CAM5.2, NF, TTF-1, MCPyVLTAg, and high-risk human papilloma virus facilitate the distinction of MCC from SCNEC. Proper identification of vulvar HGNECs is critical for patient management.