Pernicious Anemia and Vitamin B12 Deficiency Presenting As Pseudothrombotic Microangiopathy and Developing Secondary Thrombocytopenia After Treatment: A Case Report

Pernicious anemia (PA) is an autoimmune disease secondary to chronic atrophic gastritis leading to vitamin B12 deficiency. Rarely, some patients may develop advanced hematological complications that mimic those of thrombotic thrombocytopenic purpura (TTP). Differentiating these conditions is crucial because they require different management. We present a case of a 68-year-old male who presented with generalized weakness, fatigue, and shortness of breath. This patient had anemia, thrombocytopenia, and a markedly deficient serum level of vitamin B12. The symptoms initially mimicked those associated with TTP, but the activity of ADAMTS 13 was normal. A diagnosis of pseudo-TTP has been made due to vitamin B12 deficiency resulting from PA with reactive thrombocytosis. Ultimately, vitamin B12 deficiency pseudo-TTP should be considered a differential diagnosis for therapy refractory TTP because of its different management strategies ranging from parenteral Vitamin B12 in PA patients with highly favorable outcomes to more advanced treatment with less favorable outcomes in TTP patients.

Reactive Thrombocytosis Related Cerebral Venous Thrombosis: A Rare Complication of Untreated Iron Deficiency Anemia

Thrombocytosis can be either primary or secondary, and it can cause venous pro-thrombotic states like cerebral venous thrombosis. Untreated iron deficiency anemia is postulated to cause reactive (secondary) thrombocytosis due to the proliferation of common progenitor cells. Here we present a case of a middle-aged woman with polycystic ovary syndrome and episodes of menorrhagia. She presented with headache and focal sensory deficits, and her neuroimaging showed evidence of cerebral venous sinus thrombosis (CVST). Laboratory tests showed microcytic hypochromic anemia, low ferritin, high total iron-binding capacity (TIBC), and thrombocytosis with a platelet count of 1,523,000/mm³. A comprehensive workup for hypercoagulable states and primary causes of thrombocytosis was negative. It was concluded that the etiology of her CVST was a reactive thrombocytosis from chronic untreated iron deficiency anemia. Anticoagulation with apixaban and corrective treatment for iron deficiency anemia was initiated. A repeated neuroimaging after four months showed significantly less clot burden in the cerebral venous sinuses, and then apixaban was stopped after six months. Laboratory tests after one year of iron replacement therapy showed improvement in the hemoglobin and hematocrit as well as normalization of platelet count. This case highlights a rare yet potentially dangerous complication of a common untreated condition, i.e., iron deficiency anemia. 

Severe Iron Deficiency Anemia Leading to Thrombocytosis With Arterial and Venous Thrombosis

A 45-year-old female who was a teacher by profession with a history of chronic asymptomatic anemia in the past presented to our hospital with complaints of intermittent fever for two weeks, cough with expectoration, dyspnea on exertion, and left upper limb edema for four days. She had a history of abdominal pain after food intake. She gave a history of having anemia for the past 23 years. Evaluation after admission showed raised inflammatory markers, marked thrombocytosis, and severe iron deficiency anemia. Further imaging in the form of a CT of the abdomen and thorax showed that she had a left-sided pleural effusion which showed an exudative picture, splenomegaly with a splenic infarct with a splenic abscess, and a suprarenal abdominal aorta thrombus. She was also found to have deep vein thrombosis (DVT) of the left subclavian and proximal internal jugular vein in a ultrasonogram (USG) Doppler. The workup done ruled out congenital and acquired causes of thrombosis and after extensive evaluation the patient was found to have unexplained thrombosis. The cause of unexplained thrombosis is the point of interest in this patient. Despite extensive workup, no precise cause for thrombosis, which was both arterial and venous in nature could be found out initially. Hence by exclusion, the possibility of secondary thrombocytosis causing the thrombosis was considered. Over the next few years, this patient underwent repeat esophageal endoscopies, colonoscopies, and capsule studies all without being able to pinpoint a diagnosis. Eventually three years later, a CT enteroscopy with biopsy showed the diagnosis of Crohn’s disease and the patient was started on appropriate immunosuppressive treatment for the same. There have been multiple case reports of thrombocytosis causing arterial or venous thrombus but not many have recorded both arterial and venous thrombosis in the same patient.