Gastric carcinoid is a rare type of gastric malignancy accounting for around 7% of all gastrointestinal neuroendocrine tumours (NETs). While most gastric NETs (gNETs) are readily visible through direct visualisation by upper endoscopy, around 25% of gastric carcinoids are invisible because they are located in the submucosal gastric regions of the body and fundus. gNETs located in the intra-mucosal areas can be identified by gastric mapping; this can be done by taking random gastric biopsies from the antrum, body and fundus. We report a case of a well-differentiated gastric NET type 1 with atrophic gastritis diagnosed on upper endoscopy and pathological immunohistochemistry staining.
CONCLUSIONS: The case highlights that not all gNETs are visible under direct endoscopic visualisation.It is essential to understand the different types of gNETs.Understand that both type and size of gNETs impact therapeutic implications and prognosis.

Hyperpigmentation is a recognized sign of vitamin B12 deficiency that resolves after vitamin repletion. We present the case of a 58-year-old female with neuropsychiatric symptoms who developed progressive darkening of her hands and feet. A diagnosis of vitamin B12 deficiency secondary to pernicious anemia was made and her symptoms and hyperpigmentation resolved following vitamin repletion. Clinicians should consider vitamin B12 deficiency in the differential diagnosis of palmoplantar hyperpigmentation, as early treatment can avert permanent disability in these patients.

BACKGROUND: Vitamin B12 deficiency is primarily associated with pernicious anaemia, polyneuropathy, and spinal-cord disease, but publications on its association with hallucinations are on the rise.
METHODS: I carried out a systematic literature search on these hallucinations in PubMed, PsycINFO, and Google Scholar, up until July 1, 2023.
RESULTS: The search yielded 50 case studies published between 1960 and 2023. The hallucinations described therein are predominantly visual and/or auditory in nature, with 20% being specified as complex, compound, or panoramic. They are often described in the context of vitamin B12-related neuropsychiatric conditions such as dementia, delirium, epilepsy, psychotic disorder, schizoaffective disorder, bipolar disorder, depressive disorder, catatonia, or obsessive-compulsive disorder. In the context of such disorders, they tend to appear first and also often appear to be the first to disappear with cobalamin treatment. Within an average of 2 months, full amelioration was thus obtained in 75% of the cases and partial amelioration in the remaining 25%. Remarkably, a quarter of the cases involved therapy-resistant hallucinations that fully resolved under cobalamin monotherapy, while other neuropsychiatric manifestations of vitamin B12 deficiency disappeared in 60% of the treated cases. Only 32% of the cases involved comorbid pernicious anaemia. This suggests that two separate or diverging pathways exist for perceptual and haematological symptoms of vitamin B12 deficiency.
CONCLUSIONS: In the light of the high prevalence rate of vitamin B12 deficiency in the general population, the findings here presented should be interpreted with great caution. Nonetheless, they offer cues for further research and experimental application in clinical practice. This may be especially relevant in light of the recent increase in the popularity of vegetarianism and the recreational use of nitrous oxide (laughing gas), which are both risk factors for vitamin B12 deficiency.

OBJECTIVE: We aimed to assess gastrointestinal cancers risks in a large cohort of individuals with primary antibody deficiency (PAD) and their association with risk of autoimmune and inflammatory gastrointestinal diseases.
METHODS: Investigating a French national database of inpatient admissions between 2010 and 2018, we identified 12,748 patients with PAD and 38,244 control non-exposed individuals. We performed multiple exposed-non-exposed studies using conditional logistic regression.
RESULTS: In comparison with non-exposed patients, PAD patients had increased risk of in situ gastric carcinoma (Odds Ratio (OR) =10.5 [95 % CI 2.2; 50.5]), malignant gastric tumor (OR=3.2 [95 % CI 2.2; 4.4]) and colorectal cancer (OR=1.2 [95 % CI 1; 1.5]). PAD patients had also increased risk of pernicious anaemia (OR=8 |95 % CI 5.6; 11.5]), Crohn\'s disease (OR= 4.4 [95 % CI 3.5; 5.6]), ulcerative colitis (OR=2.9 [95 % CI 2.4; 3.6]) and coeliac disease (OR=13.3 [95 % CI 9.1; 19.5]). Within patients with gastric cancer, those with PAD had increased risk of pernicious anaemia (OR=8.4 [95 % CI 1.5; 215]; p = 0.01) but not of H. pylori infection.
CONCLUSIONS: Risk of gastric cancer is particularly high in PAD patients and notably risk of in situ gastric carcinoma in association with pernicious anaemia. It supports indication of early endoscopic screening in these patients.

BACKGROUND: Pseudo-thrombotic microangiopathy (pseudo- thrombotic microangiopathy (TMA)) is a rare presentation of B12 deficiency. Overlapping features like elevated LDH/total bilirubin with low haemoglobin/haptoglobin/platelets could deceivingly suggest thrombotic thrombocytopenic purpura (TTP) resulting in avoidable procedures/treatments.
METHODS: A 36-year-old female with hypothyroidism initially presented to clinic with fatigue, palpitations, lightheadedness, and dyspnoea over a 3-month duration and was found to have a haemoglobin of 5.7 g/dL. She received two packed red blood cell units in the emergency room and subsequently discharged with outpatient follow-up and empiric oral iron. During her follow-up visit, she was found to have easy bruisability, gum bleeding, and generalized weakness from hemolytic anaemia (mean corpuscular volume (MCV) 90 fL, haptoglobin <8 mg/dL, LDH >4,000 U/L and schistocytosis on CBC) and thrombocytopenia of 52 K/uL. Due to PLASMIC score of 6 and suspicion for TTP, she was transferred to our facility and tr eated with three cycles of plasma exchange and prednisone but were discontinued when ADAMTS13 levels returned normal. While the patient had normal B12 levels, further testing revealed positive intrinsic factor antibodies (IF-Ab) and an elevated MMA level of 1.56 umol/L. Replacement with cobalamin led to normalization of labs and symptoms.
CONCLUSIONS: Timely diagnosis of pseudo-TMA was exceptionally challenging due to several overlapping features with TTP including normal B12 and normal MCV. B12 levels may falsely appear normal in pernicious anemia due to IF-Ab interference with chemiluminescent immunoassay. Schistocytes lower the MCV in automated cell counters. Lower reticulocyte index (<2%), presence of immature/large platelets and teardrop cells, elevated MMA and a higher LDH (>2500) are indicative of B12 deficiency.

Variation in vitamin B12 levels has been associated with a range of diseases across the life-course, the causal nature of which remains elusive. We aimed to interrogate genetically predicted vitamin B12 status in relation to a plethora of clinical outcomes available in the UK Biobank. Genome-wide association study (GWAS) summary data obtained from a Danish and Icelandic cohort of 45,576 individuals were used to identify 8 genetic variants associated with vitamin B12 levels, serving as genetic instruments for vitamin B12 status in subsequent analyses. We conducted a Mendelian randomisation (MR)-phenome-wide association study (PheWAS) of vitamin B12 status with 945 distinct phenotypes in 439,738 individuals from the UK Biobank using these 8 genetic instruments to proxy alterations in vitamin B12 status. We used external GWAS summary statistics for replication of significant findings. Correction for multiple testing was taken into consideration using a 5% false discovery rate (FDR) threshold. MR analysis identified an association between higher genetically predicted vitamin B12 status and lower risk of vitamin B deficiency (including all B vitamin deficiencies), serving as a positive control outcome. We further identified associations between higher genetically predicted vitamin B12 status and a reduced risk of megaloblastic anaemia (OR = 0.35, 95% CI: 0.20-0.50) and pernicious anaemia (0.29, 0.19-0.45), which was supported in replication analyses. Our study highlights that higher genetically predicted vitamin B12 status is potentially protective of risk of vitamin B12 deficiency associated with pernicious anaemia diagnosis, and reduces risk of megaloblastic anaemia. The potential use of genetically predicted vitamin B12 status in disease diagnosis, progression and management remains to be investigated.

UNASSIGNED: Pernicious Anaemia is a rare autoimmune disorder prevalent among 0.1% of the general population and is characterised by decreased cobalamin absorption. This condition is overlooked because of its rarity, insidious onset of non-specific symptoms and clinically asymptomatic state. Elevated serum intrinsic factor antibody level along with reduced Vitamin B12 level confirms the diagnosis.
UNASSIGNED: Pallor and abdominal tenderness was present. Haematological investigations showed elevated platelet count, elevated Mean Cell Volume reduced haemoglobin level(11.4 g/dl), reduced Vitamin B12 and high serum intrinsic factor antibody level. Serum parietal cell antibody was positive. The patient responded well to parenteral Vitamin B12.
UNASSIGNED: In Pernicious anaemia, serum intrinsic factor antibody and parietal cell antibody are high which are responsible for reduced Vitamin B12 absorption. Studies have also shown positive correlation between H pylori and Pernicious Anaemia. Neurological symptoms are less common but may present as paraesthesia, changes in gait or spasticity due to peripheral neuropathy. It is also associated with autoimmune diseases. Untreated pernicious anaemia can lead to neurological and gastrointestinal complications.
UNASSIGNED: Pernicious Anaemia is an overlooked condition because of its insidious onset of non-specific symptoms, clinically asymptomatic state, rarity and therefore timely diagnosis of Pernicious Anaemia still remains a challenge.

Autoimmune atrophic gastritis (AAG) is rarely associated with coeliac disease (CD).
To assess the frequency of AAG-CD association and to compare clinical, biochemical, and histological features of adults affected by both diseases (cases) with AAG controls.
This case-control study included 9 cases (F55%, median age 47, range 23-59yrs) matched (1:3) by age (±4 yrs) and gender to 27 controls randomly selected from our AAG cohort (2009-2021). The AAG and CD diagnosis was based on internationally agreed criteria.
Of 434 AAG patients (median age:62.5yrs, range18-92yrs, F:M ratio=2.2:1),9 had a concomitant diagnosis of CD. The occurrence of AAG-CD association was 2% and 1.65% among AAG/CD cohorts, respectively. Cases were significantly younger than AAG cohort (n = 425, p = 0.002). In 4/9cases, AAG was diagnosed by proactive screening for autoimmune disorders. Autoimmune thyroid disorders were present in 5/9 cases. Cases had a significant higher prevalence of normocytic anaemia than controls (p = 0.004). No significant differences were found between cases and controls concerning clinical and histological features.
AAG-CD association is rare. Gastric and duodenal biopsies might be advisable in young people with normocytic anaemia and associated autoimmune disorders to timely diagnose clinically silent conditions.

The association between malignancies and autoimmunity had been well-established. The proposed pathophysiology and causality can be bidirectional. For example, a paraneoplastic syndrome can be triggered by an underlying malignancy or vice versa, where chronic inflammation of organs affected by autoimmunity can induce malignant transformation such as the case with inflammatory bowel disease and colorectal cancer or primary sclerosing cholangitis and hepatobiliary cancer. This report presents a case of autoimmune phenomena, namely, autoimmune hemolytic anemia, pernicious anemia, and Graves disease associated with newly diagnosed breast cancer. We also highlight the postulated pathophysiologic mechanisms in an attempt to answer the question of whether the occurrence of these autoimmune phenomena in our patient is a result of the law of parsimony (Occam\'s razor), where clinical variables are pathogenically related, or the counterargument, where random events and diseases can take place simultaneously (Hickam\'s dictum).

Macrocytosis is defined as a mean corpuscular volume greater than 100 femtolitres (fL). There are several causes for macrocytic anaemia, and they can be divided into megaloblastic or non-megaloblastic anaemia. Vitamin B12 deficiency is one of the most common causes of megaloblastic anaemia. The cause of vitamin B12 deficiency must be evaluated including the presence of pernicious anaemia as it could alter the treatment and follow-up. Pernicious anaemia can be associated with other autoimmune diseases constituting polyglandular syndromes.