Metastasis into parapharyngeal lymph node in papilary thyroid cancer

Overview

54-year old man underwent total thyroidectomy and right block neck dissection with histological evidence of papillary carcinoma with metastatic nodal involvement. After the therapy of 3.7 GBq ¹³¹I and subsequent bilateral cervical revision with identification of positive nodal metastases he underwent additional therapy of 7.4 GBq ¹³¹I 6 months later. The posttherapeutic scintigraphy revealed persistent residual tissue of the thyroid gland and nodal metastasis located in the parapharyngeal space in front of the cervical spine at the level of C1-C2. The precise localization was allowed by hybrid SPECT/CT imaging. The spread of tumor cranially (retrogradely) requires the involvement of the retropharyngeal lymph pathways. Cervical lymph node dissection and metastatic involvement of cervical lymph nodes may change the direction of lymphatic drainage retrogradely, resulting in unusual localization of metastases in para- or retropharyngeal space.

Key words:
carcinoma of the thyroid gland, parapharyngeal lymph node metastasis, hybrid SPECT/CT imaging