Endocrine Abstracts

Introduction: Untreated hypothyroidism may lead to decompensation of a patient’s homeostasis. While the association between hypothyroidism and anemia has been noted previously, there are very few, cases of white cell lines and platelet counts being affected by hypothyroidism alone. To demonstrate a rare but significant manifestation of hypothyroidism, we present a unique and interesting case of pancytopenia secondary to severe hypothyroidism.

Case report: A70-year-old women, with a past history of diabetes and hypertention for 10 years receiving respectively losartan 50 mg and premixed insulin, patient was admitted for a glycemic imbalance with an HBA1c of 16%, we note a, chronic constipation, progressive weight gain, cold intolerance and drowsiness, there were no signs of adrenal insufficiency. Temperature was 37°C, blood pressure 120/70 mmHg, heart rate 60 beats per minute, with facial myxoedema and normal heart sounds. There was no hepatosplenomegaly. The patient’s TSH was 92 mIU/l (0.27–4.2), with total T4 of 1.3 pmol/l (12–22). Antithyroid peroxidase antibodies were not detectable. White cell count was 398 000/ml, hemoglobin 11 g/dl, platelet count 98,000/ml, and mean corpuscular volume 82 fL/cell. Blood smear demonstrated absolute neutropenia, thrombocytopenia and normocytic anemia. The cervical ultrasound finds a thyroid gland of heterogeneous hypoechoic echostructure traversed by hyperechoic trabeculae, transthoracic ultrasonography found a left ventricular hypertrophy, ejection fraction preserved at 60% and a dry pericardium. a low dose of levothyrox was started 12.5 μg/day with an increase of 12.5 μg/15J according to clinical and electrocardiographic tolerance, hydrocortisone substitution was started before levothyrox substitution. 4 weeks later, repeated blood counts citrate tube with blood smear and reticulocyte showed resolution of pancytopenia.

Conclusion: We describe a rare complication of severe hypothyroidism, pancytopenia, and its complete reversal after 1 month of thyroid hormone replacement. Mechanisms of this process remain unclear. Interestingly, the lack of detectable antithyroid peroxidase antibodies, like in our case, makes a hematopoietic antigen-antibody reaction a less likely etiology. In cases of unexplained pancytopenia, hypothyroidism should be considered in the differential diagnosis. Further basic studies are needed to determine this underlying disease mechanism.