Teaching cases

Case presentation: Female. 66 y.o. Recurrence of multinodular goiter (MNG) with intra-thoracic extension. History of mild, intermittent asthma and chronic hypertension treated with ACEI, with no cardiovascular symptoms. Her MNG was discovered 33 years before, treated with subtotal thyroidectomy, with benign changes on pathology examination. Seven years ago she had a thyroid scintigram performed using 99mTc pertechnetate which revealed significant residual thyroid tissue extending to mediastinum, with globally decreased uptake. She received no treatment at that time. Two years later she presented with large MNG recurrence, surgery being contraindicated because of anatomic considerations. Radiometabolic treatment was performed with 30 mCi of 131I in an attempt to reduce gland volume. Teaching points: Recombinant human TSH (rhTSH)-stimulated iodine scintigraphy is an effective and safe alternative to thyroid hormone withdrawal,to be used during the post-surgical follow-up of papillary and follicular thyroid cancer. Its clinical efficiency for the detection of persistent and recurrent disease is similar to that of thyroid hormone withdrawal. As a novel clinical application, compressive goiters with benign changes and low uptake of 131I can be efficiently treated with the use of rhTSH. Recombinant human TSH-stimulated radioiodine therapy of nodular goiter allows major reduction of the radiation burden with retained efficacy.

Case presentation: Female. 66 y.o. Recurrence of multinodular goiter (MNG) with intra-thoracic extension. History of mild, intermittent asthma and chronic hypertension treated with ACEI, with no cardiovascular symptoms. Her MNG was discovered 33 years before, treated with subtotal thyroidectomy, with benign changes on pathology examination. Seven years ago she had a thyroid scintigram performed using 99mTc pertechnetate which revealed significant residual thyroid tissue extending to mediastinum, with globally decreased uptake. She received no treatment at that time. Two years later she presented with large MNG recurrence, surgery being contraindicated because of anatomic considerations. Radiometabolic treatment was performed with 30 mCi of 131I in an attempt to reduce gland volume. Teaching points: Recombinant human TSH (rhTSH)-stimulated iodine scintigraphy is an effective and safe alternative to thyroid hormone withdrawal,to be used during the post-surgical follow-up of papillary and follicular thyroid cancer. Its clinical efficiency for the detection of persistent and recurrent disease is similar to that of thyroid hormone withdrawal. As a novel clinical application, compressive goiters with benign changes and low uptake of 131I can be efficiently treated with the use of rhTSH. Recombinant human TSH-stimulated radioiodine therapy of nodular goiter allows major reduction of the radiation burden with retained efficacy.

Teaching points: Therapy with 177Lutetium DOTA TATE can be useful for inoperable, metastatic GEP NETs. The rate of complete responses obtained by Kwekkeboom et al was only 2% in patients treated with 177Lu-DOTA TATE. They reported partial responses, minor responses, stable disease and progressive disease, respectively, in 26%, 19%, 35% and 15% of their patients. Treatment tolerance was good, significant reduction of symptoms was obtained and 2-yr survival rate was 76 ± 16%. Predictors of good response include: high uptake of lesions in somatostatin receptor scintigraphy and Karnofky’s performance status > 70%. Predictors of poor prognosis include: massive liver involvement, bone metastases and Karnofky’s index < 70%.

Teaching points: Causes of I-131 Unrelated to Thyroid Cancer Choroid plexus salivary glands, gastric mucosa, urinary tract; contamination by physiological sections. Ectopic gastric mucosa, other gastrointestinal abnormalities, urinary tract abnormalities, mammary abnormalities. Serous cavities and cysts. Inflammation and infection. Nonthyroidal neoplasms. Unexplained causes. Choroid plexus salivary glands, gastric mucosa, urinary tract; contamination by physiological sections. Ectopic gastric mucosa, other gastrointestinal abnormalities, urinary tract abnormalities, mammary abnormalities. Serous cavities and cysts. Inflammation and infection. Nonthyroidal neoplasms. Unexplained causes.

Case presentation: Female. 42y.o. In addition to overt hyperthyroidism, positive anti-Tgand antiTSH-receptor auto-antibodies. Graves’ disease. Teaching points: Radioiodine treatment is a well established, safe and effective therapeutic modality for Graves' disease. Autoimmune thyroid diseases are frequently associated with differentiated thyroid carcinomas. Nodule(s) in Graves' disease must always be evaluated with FNAC (especially if “cold”on thyroid scintigraphy).

Case presentation: Male. 50 y.o. Thyroid carcinoma. Tumor of intermediate differentiation andhigh biological aggressiveness, accounting for 2% -6% of all thyroid cancers.? Total thyroidectomyin 1995becauseofsuspectedthyroid canceron FNAC. Histology: poorlydifferentiatedthyroidcancer(insulartype) withlymphnodemetastasisin the centralcompartment (pT3N1aMx). Teaching points: Management of poorly differentiated thyroid cancer.

Case presentations: Female. 75y.o. Virtually asymptomatic and previously submitted to thyroidectomybecause of multinodulargoiter (in 2004). Referred to Nuclear Medicine after surgical debulkingof a lumbar mass whose histology showed metastasis from welldifferentiated thyroid cancer. Teaching points: Occult differentiated thyroid carcinoma (DTC) can be present in multinodulargoiter. DTCsare slow-growing and are usually treatable by combined surgery of the primary tumor, radio-iodine, and TSH-suppressive therapy. Tumor cell imaging with radioiodine (131I-or 123I-iodide) whole-body scan (WBS) is specific and sensitive for well differentiated DTC (especially if combined with TSHstimulated serum Tg assay). In selected instances, surgical debulking of metastatic lesions can be beneficial to patients.

Case presentation: Female. 75 y.o. Hyperfunctioning adenoma in the right thyroid lobe, slowly increasing size over time. She has been on treatment for several years with methimazole 5mg/day. Teaching points: Management of thyroid nodule. Radioiodine therapy of hyperthyroidism.