Endocrine Abstracts

A 52 year old lady presented with a six month history of weight loss and fatigue. Physical examination showed mild abdominal discomfort on the right flank with signs of anemia. Blood pressure was 130/60 mmHg, pulse was 83 bpm regular. Tender goitre or tremor were not present. Laboratory tests revealed tsh: 0.008 mUI/l (0.37-4.45), fT4: 2.12 ng/dl (0.8-1.8), thyroglobulin 40 ng/ml (5-42), TPO-Ab <35 IU/ml and TgAb <20 IU/ml, sedimentation:72 mm/h, crp: 59 mg/dl with normal renal, liver function test and urine dip. Previous thyroid results dated a year ago were normal. Abdominal computed tomography (CT) and thyroid ultrasound were requested. Ultrasound revealed heterogeneous echogenicity with 10 and 14 mm hyperechoic nodules on the right thyroid gland. Thyroid scan revealed a generalised decreased uptake. Abdominal CT scan revealed a 5x8 cm exophytic right renal mass with necrotic features, another 4x6,1 cm necrotic conglomerate mass which is suspicious of lymphadenopathy in the right renal hilus, pressing the right renal vein and right vena cava inferior were reported. Due to the suspicion of renal cell carcinoma (RCC), requested thorax CT showed 2.8 cm necrotic left hilar lymphadenopathy and 1 cm parenchymal nodule suspicious of metastasis in the left lingula. To assess possible paraneoplastic features, β-hcg, afp and ldh levels were measured and reported as normal. Patient was referred to the urology department for right nephrectomy and lymphadenectomy. Pathology results were consistent with stage four renal cell carcinoma. Patient was transferred to the medical oncology team for chemotherapy and follow-up. Fine-needle aspiration biopsy revealed degenerated follicular cells, multinucleated giant cells and epithelioid changes, consistent with chronic granulomatous thyroiditis. 6 weeks after the nephrectomy, thyroid functions returned to normal with tsh:0.82 mUI/l and ft4:1.78 ng/dl, which was suggestive of a subacute thyroiditis secondary to renal cell carcinoma. Literature review showed only one other similar case (1). RCC is known with its’ variety of paraneoplastic features. unique inflammatory and immune-mediated responses(2). Pathophysiological role of IL-6, an inflammatory cytokine which is related to high crp levels as well, is also associated with thyroiditis as well(3).

References: 1. Algün E, Alici S, Topal C, et al.‘Coexistence of subacute thyroiditis and renal cell carcinoma:a paraneoplastic syndrome’CMAJ. 2003 15;168(8):985-6.

2. Hsieh JJ, Purdue MP, Signoretti S, et al. ‘Renal cell carcinoma.’ Nat Rev Dis Primers.2017 9;3:17009.

3. Fallahi P, Ferrari SM, Elia G et al. ‘Cytokines as Targets of Novel Therapies for Graves’ Ophthalmopathy. Front Endocrinol. 2021 Apr 16;12:654473