Secondary pituitary hormonal dysfunction patterns: tumor size and subtype matter.

PURPOSE: Patients with sellar masses (SM) frequently have secondary hormonal deficiency (SHD) at initial presentation. While larger SM are more likely to present with SHD, it is unclear whether SHD at presentation is influenced by the type of SM. METHODS: We conducted a retrospective analysis of patients with SM prospectively enrolled in our comprehensive provincial neuropituitary registry between November 2005 and December 2018. SM were subdivided based on size: < 1 cm, 1-1.9 cm, 2-2.9 cm, and > 3 cm. RESULTS: A total of 914 patients met the inclusion criteria, including: 346 nonfunctioning adenomas (NFA), 261 prolactinomas (PRLoma), 51 growth hormone adenomas, 36 adrenocorticotropic adenomas, 93 Rathke's cleft cysts, 70 craniopharyngiomas and 57 meningiomas. The overall rate of SHD at presentation was highest in PRLoma (62.8%) and craniopharyngiomas (64.3%) and lowest in meningiomas (14%). While larger SM were significantly more likely to have SHD, the rate of SHD within each group was significantly different despite similar size (p < 0.001). Of the two largest groups of SM (NFA and PRLoma), NFA had significantly higher odds ratio (3.34, CI 1.89-5.89) of having multiple SHDs when compare with PRLoma, even when corrected for age, gender and size of tumor (p < 0.001). CONCLUSION: Our study shows that the rate and distribution of SHD in SM vary dependent upon the size of the tumor and specific pathology; in particular, NFA are more likely to present with multiple SHDs. Our data will help clinicians in determining adequate hormonal testing strategy for different SM.

ACTH-Secreting Neuroendocrine Carcinoma of the Cecum: Case Report and Review of the Literature.

BACKGROUND: Approximately 30% of neuroendocrine tumors (NETs) present with secretory syndromes or develop one during the course of the disease. Cushing syndrome caused by a gastrointestinal tract NET is rare, with limited published information. We describe a patient with florid Cushing syndrome due to ectopic adrenocorticotropic hormone (ACTH) from a NET of colonic origin. A literature review was conducted to describe the spectrum of this clinical and pathologic entity as reported in the scientific literature. PATIENT AND METHODS: Next-generation sequencing and microsatellite instability testing was carried out on the tumor from our case. A preliminary PubMed search was conducted using the following terms under the publication type "Case Reports": "Cushing" AND "colon," "neuroendocrine" AND "colon" and "neuroendocrine AND Cushing AND "colon." A manual search was performed to review all references for inclusion and relevant clinical, biochemical and pathologic data was abstracted. RESULTS: Mutations in BRAF V600E and TP53 were detected in our case. We retrieved 18 previously reported cases of Cushing syndrome associated with a NET of colonic origin, none of which had next-generation sequencing performed. Median age at diagnosis was 54.5 years (range, 24-74 years), with equal gender distribution. ACTH was detected by immunohistochemistry in the primary tumor and/or metastatic lesion in 61.5%. Review of the reports suggested that ectopic ACTH secretion from a colonic tumor might be more common in mixed glandular and NETs, including mixed adenocarcinoma-neuroendocrine carcinoma. Among studies reporting outcomes, the unadjusted mortality rate was 77.7%, with median overall survival from presentation of 63 days (range, 17-380 days). CONCLUSION: Cushing syndrome associated with ectopic ACTH from tumors of colonic origin is a rare phenomenon with poor outcomes and can be associated with pure NETs, adenocarcinomas, and mixed-phenotype tumors, including mixed adenocarcinoma-neuroendocrine carcinoma.

A comparative, population-based analysis of pituitary incidentalomas vs clinically manifesting sellar masses.

PURPOSE: Sellar masses may present either with clinical manifestations of mass effect/hormonal dysfunction (CMSM) or incidentally on imaging (pituitary incidentaloma (PI)). This novel population-based study compares these two entities. METHODS: Retrospective analysis of all patients within a provincial pituitary registry between January 2006 and June 2014. RESULTS: Nine hundred and three patients were included (681 CMSM, 222 PI). CMSM mainly presented with secondary hormone deficiencies (SHDs) or stalk compression (29.7%), whereas PIs were found in association with neurological complaints (34.2%) (P < 0.0001). PIs were more likely to be macroadenomas (70.7 vs 49.9%; P < 0.0001). The commonest pathologies among CMSM were prolactinomas (39.8%) and non-functioning adenomas (NFAs) (50%) in PI (P < 0.0001). SHDs were present in 41.3% CMSM and 31.1% PI patients (P < 0.0001) and visual field deficit in 24.2 and 29.3%, respectively (P = 0.16). CMSM were more likely to require surgery (62.9%) than PI (35.8%) (P < 0.0005). The commonest surgical indications were impaired vision and radiological evidence of optic nerve compression. Over a follow-up period of 5.7 years for CMSM and 5.0 years for PI, tumour growth/recurrence occurred in 7.8% of surgically treated CMSM and 2.6% without surgery and PI, 0 and 4.9%, respectively (P = 1.0). There were no significant differences in the risk of new-onset SHD in CMSM vs PI in those who underwent surgery (P = 0.7) and those who were followed without surgery (P = 0.58). CONCLUSIONS: This novel study compares the long-term trends of PI with CMSM, highlighting the need for comprehensive baseline and long-term radiological and hormonal evaluations in both entities.

Regulation of CDX2 expression in esophageal adenocarcinoma.

Reflux of acidic gastric contents and bile acids into the lower esophagus has been identified to have a central role in esophageal malignancy and is reported to upregulate caudal-related homologue 2 (CDX2), a regulatory gene involved in embryonic development and axial patterning of the alimentary tract. The aim of this study was to characterize the expression of CDX2 in a well-defined series of human esophageal tissues, comprising reflux-induced esophagitis, premalignant Barrett esophagus (BE), and primary esophageal adenocarcinoma (EADC). To explore potential molecular regulatory mechanisms, we also studied the expression of beta-catenin, SOX9, and CDX2 promoter methylation in esophageal tissues, in addition to the effect of bile acids and nitric oxide (NO) on CDX2 expression in the normal human esophageal cell line Het1A. Relative to matched normal esophageal epithelia, CDX2 was overexpressed in esophagitis (37% for RNA; cytoplasmic immunoreactivity in 48% of tissues), a high proportion (91%) of BE tissues, and in EADC (57% for RNA; cell nuclear immunopositivity in 80%). An association with beta-catenin expression was seen, but not with SOX9 or CDX2 promoter methylation. In Het1A cells, CDX2 was upregulated following exposure to bile acids and NO, alone and in combination. These results further implicate CDX2 and beta-catenin in the molecular pathogenesis of human EADC. The observed synergistic effect of NO on the efficacy of bile acid-induction of CDX2 suggests a novel role for NO in modulating the development of the Barrett phenotype and esophageal adenocarcinogenesis.

Inducible nitric oxide synthase, nitrotyrosine and p53 mutations in the molecular pathogenesis of Barrett's esophagus and esophageal adenocarcinoma.

Nitric oxide (NO) has been implicated as a potential causative factor for endogenous p53 mutations in gastrointestinal malignancy. To investigate the role of NO in esophageal adenocarcinoma (EADC), we studied patterns of p53 mutations, expression of inducible nitric oxide synthase (iNOS) and the tissue accumulation of nitrotyrosine (NTS), a stable reaction product of NO and a marker for cellular protein damage, in human premalignant and malignant esophageal epithelia. Tissues were obtained from patients with gastroesophageal reflux disease (GERD)-induced esophagitis (n = 76), Barrett's esophagus (BE; n = 119) and primary EADC (n = 54). DNA sequencing was used to characterize p53 mutations, RT-PCR to study iNOS mRNA expression, and immunohistochemistry to study NTS. Relative to self-matched normal epithelia, a progressive increase in iNOS mRNA expression was seen in GERD (30%; 23/76), BE (48%; 57/119), and EADC (63%; 34/54) tissues (P < 0.001). Among patients with EADC, elevated levels of NTS immunoreactivity were more frequent in tumors with p53 mutations (11/21; 52%) compared with tumors with wild-type p53 (9/33; 27%; P = 0.063), and specifically in tumors with p53 mutations at CpG dinucleotides (10/12; 83%) compared with non-CpG p53 mutations (1/9; 11%; P = 0.008). The increasing frequency of iNOS (mRNA) overexpression in GERD, BE and EADC supports the hypothesis that an active inflammatory process, most likely a consequence of GERD, underlies molecular progression to EADC. The highly significant association between NTS, reflecting chronic NO-induced cellular protein damage, and endogenous p53 mutations at CpG dinucleotides, provides further evidence for a molecular link between chronic inflammation and esophageal malignancy.

Microsatellite instability in esophageal adenocarcinoma.

The frequency of microsatellite instability (MSI), a result of defective mismatch repair during DNA replication, has been reported inconsistently in primary esophageal adenocarcinoma (EADC). Using a panel of 15 markers, the primary aim of this study was to analyze the frequency of MSI in a well-characterized series of 27 primary EADCs, defined according to strict clinicopathologic criteria. Polymerase chain reaction was used to amplify the following microsatellite repeat loci: D2S123, D10S197, D2S119, D11S904, D2S147, D3S1764, D7S1830, D7S1805, D2S434, D9S299, BAT25, BAT26, D5S346, D17S250, and TGF-beta-RII. Tumors were classified as microsatellite-stable (MSS) when no alterations were seen in tumor DNA compared to matched normal tissues, low-level MSI (MSI-L) when 1-5 of 15 markers were altered, and high-level MSI (MSI-H) when more than five markers were altered. Using these stringent criteria, 9/27 (33%) tumors were MSS, 18/27 (67%) tumors were MSI-L, and no tumor was MSI-H. Immunohistochemistry demonstrated cell nuclear expression of DNA mismatch repair proteins (both hMLH1 and hMSH2) in 78% (21/27) of tumors. No associations were seen between MSI and immunohistochemical expression of hMLH1, hMSH2, alterations in p53 or MBD4, tumor grade, pathologic stage, or patient survival. In conclusion, the finding of low levels of MSI in most tumors suggests an inherent baseline genomic instability, and potentially increased susceptibility to mutations during the progression of esophageal adenocarcinoma.