Endocrine Abstracts

Atypical manifestations of hyperthyroidism include hematological, cardiovascular, dermatological manifestation. Especially single lineage abnormalities such as anemia (34%), leukopenia (5.8%), thrombocytopenia (3.3%) are reported, but pancytopenia is a rare presentation of hyperthyroidism. The suspected etiologic mechanisms include ineffective hematopoiesis, reduction in blood cell life span, autoimmune process, toxicity of thyroid hormone.

We report a case of pancytopenia that was precipitated by hyperthyroidism. A 69-year-old woman presented to emergency department with more than 2 months history of general weakness, easy fatigability, weight loss of 12 kg. She took no regular medications and had no significant past medical history or family history. Laboratory data on admission were as follows: WBC 3.12 K/ul, Hb 8.4 g/dl, PLT 17 K/ul, thyroid function tests showed abnormally high concentrations of free T₄ (FT₄) and total T₃ (TT₃)(FT₄: 51.64 pmol/l, TT₃: 4.58 nmol/l) with a TSH concentration below the detection limit. TRAb 264.2 U/l, anti-Tgn 773.1 u/ml, anti-TPO 3000 u/ml. Thyroid ultrasound and thyroid scan (Tc-99 m) suggested diffuse thyroiditis. Abdominal ultrasonogram showed no abnormal findings including hepatosplenomegaly. Normocellular marrow was noted in Bone marrow aspiration and biopsy. From these results, the patient was diagnosed with pancytopenia with primary hyperthyroidism. She was started on propylthiouracil 100 mg qd, propanolol 40 mg bid and parenteral dexamethasone 1 mg bid. FT₄ and TT₃ levels decreased gradually and pancytopenia improved after 2 weeks (TSH <0.16 mu/l, FT₄ 24.42 pmol/l, TT₃ 2.34 nmol/l).

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.