Endocrine Abstracts

Introduction: Disseminated fungal disease is an opportunistic infection mostly seen in immunocompromised patients, however, fungal thyroiditis in this context is rare, with few previously reported cases (predominantly Aspergillus, only one case of paediatric candida thyroiditis). We present a case of Candida tropicalis induced thyroiditis, to highlight this rare (likely underreported) cause of thyroid disease.

Case: A 9-year-old female was diagnosed with acute lymphoblastic leukaemia (ALL). Admission cultures confirmed Candida tropicalis in stool and urine. On day 12 of induction, she developed febrile neutropenia, treated with antifungals and antibiotics. Around this time, she also developed steroid-induced diabetes and thyroid function (TFTs) revealed mild hyperthyroidism: T4-23.7pmol/L, TSH-0.35mU/L. 2 weeks later, she developed a fever recurrence. High-beta glucan levels suggested disseminated fungal infection. A leg nodule biopsy demonstrated fungal hyphae, with Candida tropicalis, confirmed on PCR and fungal culture. Retrospectively, multifocal parenchymal abnormalities were noted in an earlier renal ultrasound consistent with fungal infiltrates. 3 weeks later, in the setting of ongoing fevers and tremors, repeat TFTs confirmed hyperthyroidism (free T4-68.5pmol/L, TSH<0.02mU/L). Thyroid ultrasound: ‘irregular hypoechoic area, similar in configuration and detail to that demonstrated in the right calf, consistent with fungal lesion’. Thyroid NM pertechnetate scan: no significant tracer uptake, consistent with thyroiditis Antibodies: TRAb and TPO negative. Our patient received fluconazole and caspofungin, with ambisome introduced due to suspected resistance. She initially received propanol, while risks of neutropenia with carbimazole were debated in the oncological context. Symptoms continued and carbimazole and prednisone were added, following which fevers and tachycardia rapidly resolved.

Key Learning: • Candida fungal thyroiditis is rare, requiring a high index of suspicion in the setting of immunocompromise • Fungal thyroiditis symptoms overlap significantly with those of sepsis or underlying oncological diagnoses that many fungal-susceptible patients carry. Our patient presented with fever, tachycardia, weight loss and tremors. Neck pain was not a feature, but on direct questioning, dysphagia was evident • Rapid diagnosis aids timely introduction of antifungal and anti-thyroid medication • Our patient had a ‘herald’ leg nodule biopsied and was later found to have similar renal and thyroid lesions on imaging, sparing her the need to undergo further, more invasive biopsies.