ISPUB.COM The Internet Journal of Nuclear Medicine Volume 4 Number 2 1 of 4 Papillary Thyroid Carcinoma Metastasis Presenting As A Purely Cystic Lesion In The Neck M Urhan, H Cincik, Y Kurt, A Filiz, Y Narin, A Gungor, M Ozata Citation M Urhan, H Cincik, Y Kurt, A Filiz, Y Narin, A Gungor, M Ozata. Papillary Thyroid Carcinoma Metastasis Presenting As A Purely Cystic Lesion In The Neck. The Internet Journal of Nuclear Medicine. 2006 Volume 4 Number 2. Abstract Local lymphatic spread is common in patients with papillary thyroid carcinoma (PTC). Lymph node metastasis to the neck may undergo cystic degeneration which consequently delays the diagnosis and the treatment of underlying thyroid malignancy. In this study we presented 3 PTC patients with a cystic lesion in the neck as the only finding on physical examination. A benign etiology was considered initially, but papillary thyroid cancer was reported after surgical excision of the lesions. All patients underwent thyroid surgery and cervical lymph node dissection subsequently. INTRODUCTION Papillary thyroid carcinoma (PTC) is the most common type of endocrine tumors and constitutes approximately 1% of all malignancies. It usually presents as a mass in the thyroid gland but presentation as a lump in the neck is not rare ( 1 ). Lymph node metastasis from PTC may rarely undergo cystic transformation ( 2 ). It may be indolent and mimic the clinical course of a benign lesion which consequently delays the diagnosis and treatment of the underlying malignancy. In this study we described three PTC patients presenting with a cervical cyst as the initial finding. CASES Patient 1: A 21-year old male noticed a slow growing painless cervical mass 5 months ago. On computerized tomography (CT), a purely cystic solitary lesion which is 25X20X15 mm in size was detected in the right lateral neck (Figure 1). Figure 1 Figure 1: A purely cystic lesion (white arrow) was detected on CT of the neck. The lesion was removed by surgery and metastatic papillary carcinoma was reported. The thyroid scan was normal but a hyper-echoic area suspicious for a nodule in the very upper pole of right thyroid lob was reported in ultrasonography (US). Fine needle aspiration was performed from the cystic lesion but no malignancy was reported. Metastatic papillary thyroid carcinoma was detected when the lesion was removed by surgery. The patient underwent a second cervical dissection and total thyroidectomy. The tumor was 1.1 cm in size adjacent to the upper pole of the right thyroid lobe.