Endocrine Abstracts

Introduction: Sweet’s syndrome is a rare, acute febrile neutrophilic dermatosis, associated with a variety of inflammatory and neoplastic conditions, drug reactions and rarely with a spectrum of thyroid dysfunction. A possible link between thyroid autoimmunity and Sweet’s syndrome has been previously suggested by rare reports of Hashimoto’s thyroiditis, subacute thyroiditis and classic Graves’ disease. We describe a case of ‘atypical’ hyperthyroidism coinciding with the presentation of Sweet’s syndrome.

Case Report: A previously healthy 34-year-old woman presented with pyrexia up to 40°C for three weeks, followed by a tender papulovesicular eruption on the forearms, lower legs and chest, with intact mucosae. Laboratory testing revealed WBC 11.64×10³ /μl, neutrophils 78.9%, lymphocytes 11.8%, Hct 29%, Hb 11.8 gr/dl, Platelets 346×10³ /μl, ESR 110 mm/1 hr, TSH 0.025 μIU/ml, FT3 4.4 ng/dl (1.8–4.2 ng/dl), FT4 1.83 ng/dl (0.84–1.76 ng/dl) negative anti-TG, anti-TPO and TSI 0.89 U/l (Φ.T. <1.75 U/l). The thyroid gland was enlarged and firm to palpation. ^99mTc scintigraphy showed diffusely increased uptake 6.16% (1.7±1.3). On thyroid ultrasound the parenchyma was distinctly nodular, consisting of multiple, uniform, solid, slightly hypoechoic, adjoining nodules 10–15 mm in diameter, with predominantly peripheral vascularity and increased vascularity in the intermediate tissue. Several reactive cervical lymph nodes were noted bilaterally. US-guided fine needle aspiration of one such nodule was consistent with Bethesda II. A skin biopsy from the right forearm was consistent with acute neutrophic dermatosis without vasculitis and the patient was treated with oral methylprednisolone tapering, with rapid resolution of the symptoms and rash. She was also started on thiamazole 10 mg and soon became euthyroid. Twelve months later, she remains euthyroid on 7.5 mg/d. CT scan of the abdomen showed a lipid-rich, left adrenal incidentaloma 3.1 cm in diameter, which was found nonfunctional on testing.

Conclusion: This unusual presentation of hyperthyroidism in association with Sweet’s syndrome has not been previously described and is notable because it features characteristics shared between Graves’ disease and multinodular goiter, displaying a true overlap or unclassified form of thyrotoxicosis.