BACKGROUND: Megaloblastic anemia is a subtype of anemia with increased red blood cell volume. These megaloblastic cells can be easily destroyed in the bone marrow and spleen, leading to ineffective hematopoiesis. Insulin-degrading enzymes (IDE) in erythrocytes can break down the insulin into amino acid fragments; thus, when hemolysis occurs, IDE can be released into the blood, resulting in low insulin measurement values.
METHODS: This article reports a case of false insulin test results due to the hemolysis resulting from megaloblastic anemia.
RESULTS: The patient\'s first fasting glucose results indicated that the glucose and C-peptide levels were within the normal range while her insulin level was abnormally low. After hemolysis was corrected, the relevant indicators were re-evaluated and all the results were normal.
CONCLUSIONS: This article reports a patient diagnosed with megaloblastic anemia, whose dysmorphic erythrocytes cause severe extravascular hemolysis. It was the occurrence of hemolysis that the IDE released into the blood, leading to the abnormal insulin test result.

BACKGROUND: Vitamin B12 is primarily transported from plasma to cells by Transcobalamin. Deficiency of Transcobalamin is a rare autosomal recessive disorder that results in unavailability of cobalamin in cells and accumulation of homocysteine and methylmalonic acid.
METHODS: We report a case of a 2-year-old male child with persistent pancytopenia, recurrent infections, and megaloblastic anemia. Next-generation sequencing identified a novel variant in exon 8 of TCN2 gene. Substantial improvement has been observed following administration of high doses of parenteral methylcobalamin.
CONCLUSIONS: In patients with unresolved pancytopenia and megaloblastic anemia, Transcobalamin deficiency should be investigated and treated promptly to prevent any irreversible and harmful outcome.

BACKGROUND: Erlotinib is a first-generation, tyrosine kinase inhibitor of the epidermal growth factor receptor (EGFR-TKI) used for the treatment patients with NSCLC. Erlotinib is considered as a safe and effective treatment option, with generally good tolerance. Diarrhea and rash are the most common side effects, and more rare side effects appear in long-term real-world applications. Severe erlotinib related megaloblastic anemia is rare and remains unreported. This is the first case report of severe megaloblastic anemia in a patient with advanced lung adenocarcinoma with an EGFR L858R mutation treated with erlotinib. In this report, the clinical manifestations, diagnosis and treatment of erlotinib related severe megaloblastic anemia are described, and the possible pathogenesis and related treatment options are discussed.
METHODS: Herein, we present a 57- year-old non-smoking female diagnosed with metastatic lung adenocarcinoma harboring an EGFR L858R mutation, who had received erlotinib as the first-line therapy. After 44 weeks of treatment, the patient developed severe anemia. Anemia was manifested as megaloblastic anemia with elevated mean corpuscular volume and mean corpuscular hemoglobin. The total vitamin B12 level was below the detection limit of 50.00 pg /mL. Bone marrow smear suggested megaloblastic anemia. Her hematologic parameters were markedly recovered following the withdrawal of erlotinib and vitamin B12 supplement. As a result, the patient was diagnosed with erlotinib-associated megaloblastic anemia.
CONCLUSIONS: This is the first case of severe megaloblastic anemia reported with erlotinib. Few of these hematologic adverse effects have been observed in studies on erlotinib, this case report highlights this possibility for long-term erlotinib administration. Close clinical and blood monitoring is recommended for patients receiving long-term TKI therapy.

BACKGROUND: Individuals with thiamine-responsive megaloblastic anemia (TRMA) mainly manifest macrocytic anemia, sensorineural deafness, ocular complications, and nonautoimmune diabetes. Macrocytic anemia and diabetes may be responsive to high-dosage thiamine treatment, in contrast to sensorineural deafness. Little is known about the efficacy of thiamine treatment on ocular manifestations.
METHODS: Our objective is to report data from four Italian TRMA patients: in Cases 1, 2 and 3, the diagnosis of TRMA was made at 9, 14 and 27 months. In 3 out of 4 subjects, thiamine therapy allowed both normalization of hyperglycemia, with consequent insulin suspension, and macrocytic anemia. In all Cases, thiamine therapy did not resolve the clinical manifestation of deafness. In Cases 2 and 3, follow-up showed no blindness, unlike Case 4, in which treatment was started for megaloblastic anemia at age 7 but was increased to high doses only at age 25, when the genetic diagnosis of TRMA was performed.
CONCLUSIONS: Early institution of high-dose thiamine supplementation seems to prevent the development of retinal changes and optic atrophy in TRMA patients. The spectrum of clinical manifestations is broad, and it is important to describe known Cases to gain a better understanding of this rare disease.

BACKGROUND: Vitamin B12, or cobalamin deficiency, an infrequent clinical entity in pediatric age, is found almost solely in breastfed infants whose mothers are purely vegetarian, non-supplemented or with pernicious anemia. Megaloblastic anemia in infants presents with generalized weakness or irritability.
METHODS: Diagnosis is usually centered on complete blood count, vitamin dosing, and peripheral smear, which may show macrocytes, hypersegmented neutrophils, reticulocytopenia and a raised mean corpuscular volume (MCV ˃ 100 fL). Pancytopenia has also been noted.
RESULTS: We report an exclusive breastfed nine-month-old female child who presented with irritability, developmental delay, and difficulties in introducing new foods. Her initial blood count revealed pancytopenia. Vitamin B12 levels were found to be reduced. Maternal levels of Vitamin B12 were also found to be borderline low. The child was treated as per protocols, and improvement was evidenced with the return of hematological parameters to the regular and gradual advancement of milestones.
CONCLUSIONS: We aim to underscore the importance of megaloblastic anemia as an important and rare cause of anemia in infancy.

Pancytopenia in children with celiac disease (CeD) is postulated to be due to nutritional deficiency such as vitamin B12, folate and copper or an autoimmune process resulting in aplastic anemia with hypoplastic marrow. In the present case series, we report the profile and explore the etiology of pancytopenia among children with CeD. There are only a few case reports of pancytopenia in children with CeD. We enrolled newly diagnosed cases of CeD and pancytopenia presenting in the celiac disease clinic over three years. Detailed evaluation was carried out for the cause of pancytopenia. We followed up on the cases for compliance and response to gluten-free diet at three months, six months and 12 months. Twenty patients were eligible for inclusion. They were divided into two groups: one with aplastic anemia with hypoplastic marrow labeled as Gp CeD-AA and the other with megaloblastic/nutritional anemia labeled as Gp CeD-MA. Patients in Gp CeD-MA presented with classical symptoms of CeD as recurrent diarrhea, abdomen distension, pallor and poor weight gain. They had none or just one transfusion requirement and had an early and complete recovery from pancytopenia. Patients in Gp CeD-AA presented with atypical symptoms such as epistaxis, short stature, fever, pallor and weakness. They had a multiple blood transfusion requirement and had delayed and partial recovery from pancytopenia. Pancytopenia is not a disease in itself but is the presentation of an underlying disease. It can occur due to various coexisting disorders in children with CeD, which can be as simple as nutritional deficiencies to as complex as an autoimmune process or malignancy. CeD should be included in the differential diagnosis of aplastic anemia as CeD and aplastic anemia both have a similar pathological process involving T cell destruction of tissues.

Subacute combined degeneration of the spinal cord (SCD) is mainly caused by deficiency of Vitamin B12 and characterized by deep hypoesthesia, sensory ataxia and spasmodic paralysis of lower limbs. SCD often accompanies with megaloblastic anemia. Psychiatric symptoms could be the initial manifestations of SCD by lack of Vitamin B12, but are rarely considered secondary to physical discomfort and psychological factors in SCD. Additionally, treatment experience for psychiatric symptoms in SCD remains little reported.
We presented a case of a 37-year-old female who complained of being persecuted and controlled for one week and thus was admitted to the psychiatry department. Before that, she had went through persistent paresthesia and numbness of her lower extremities for two-month. Low Vitamin B12 level and hemoglobin concentration, neurologic symptoms and bone marrow smear results supported the clinical diagnosis of SCD and megaloblastic anemia. With supplementation of Vitamin B12 and blood transfusion and short-term prescription of antipsychotics and antidepressants, physical symptoms were improved and psychological symptoms disappeared within 2 weeks.
Psychiatric symptoms of SCD could be generated from lack of Vitamin B12, anemia and neurologic symptoms, where short-term use of antipsychotics and antidepressants may be effective.

Thiamine responsive megaloblastic anaemia syndrome also known as Rogers syndrome is a very rare autosomal recessive disorder. The hallmark of the disease is the presence of the classic triad of anaemia, diabetes mellitus, and sensorineural deafness. We report the case of a 14-year-old boy who presented to us with severe megaloblastic anaemia, diabetes mellitus, and sensorineural deafness. The anaemia was further complicated by acute parvovirus infection. He was put on high doses of thiamine (vitamin B1) which led to an improvement.

BACKGROUND: Hereditary folate malabsorption-a rare disorder caused by impairment of the folate transporter-can develop into severe folate deficiency manifesting as megaloblastic anemia and occasionally thrombocytopenia. Reportedly, megaloblastic anemia can manifest with hemorrhagic episodes, possibly due to ineffective platelet production and platelet dysfunction. However, life-threatening hemorrhage events in hereditary folate malabsorption have not been well investigated.
METHODS: A 3-month-old Japanese boy was transferred to our hospital due to thrombocytopenia and severe megaloblastic anemia. During a thorough examination of hematopoietic abnormalities, the patient suddenly went into cardiac arrest due to pulmonary hemorrhage. Although intravenous folate supplementation was started soon after the identification of folate deficiency, the patient died of circulatory defect and multiple organ failure. The cause of pulmonary hemorrhage, such as respiratory infection, could not be confirmed. Genetic investigation revealed a mutation in the SLC46A1 gene to be the cause of the hereditary folate malabsorption.
CONCLUSIONS: We report an infantile case of hereditary folate malabsorption that progressed to lethal pulmonary hemorrhage before folate deficiency was identified. Clinicians should consider that megaloblastic anemia could lead to severe bleeding without warning, and that nutrient supplementation should be initiated as soon as possible.

Vitamin B12 deficiency in children can cause megaloblastic anemia, poor growth, and increased chances of infections. It is an important reversible cause of bone marrow suppression which at the time of presentation can mimic hematological malignancy. Therefore, it should be considered as a differential diagnosis in cases suspected of acute leukemia. We report a case of 14 months old child who had atypical presentation of vitamin B12 deficiency. He had chronic fever, decreased feeding and increased paleness for one year. Pancytopenia with severe anemia was present along with 19% reactive/atypical cells in peripheral blood smear suggesting acute leukemia. However, bone marrow aspiration and biopsy showed features of megaloblastic anemia. Vitamin B12 level measured was very low and treatment with cyanocobalamin caused drastic improvement in the child\'s condition.