Superior mediastinal lymphadenopathy by silicosis mimicking metastasis of papillary thyroid carcinoma – Case report and literature review

Superior mediastinal lymphadenopathy by silicosis mimicking metastasis of papillary thyroid carcinoma – Case report and literature review:



Publication date: Available online 31 December 2019

Source: Auris Nasus Larynx

Author(s): Toshiaki Tsukatani, Hideki Niwa, Takeshi Komori, Tatsuya Yoneyama, Hiroyuki Tsuji, Takatoshi Michigishi, Kunihiko Yokoyama, Tomokazu Yoshizaki

Abstract

Silicosis is caused by inhalation of silica dust and is the most common type of pneumoconiosis. The characteristics of silicosis are inflammation of lung tissue and calcified lymphadenopathy of pulmonary hilum, mediastinum and paratrachea. We present a papillary thyroid carcinoma (PTC) case with paratracheal and superior mediastinal calcified lymphadenopathy caused by silicosis. The patient did not exhibit any respiratory symptoms or abnormal chest x-ray findings due to early phase silicosis. The lymph nodes were thought to be metastasis of PTC before surgery. Patient underwent total thyroidectomy with neck and superior mediastinum dissection. Post-surgery pathological examination exhibited coexistence of silica nodules and micrometastasis of PTC in paratracheal lymph nodes, but only silica nodules were observed in superior mediastinum lymph nodes. Patient's occupation was office worker but had worked as a stonemason for several decades prior. This is a first observed case of superior mediastinal lymphadenopathy by silicosis mimicking metastasis of PTC. Benign calcified lymphadenopathy may mimic metastasis of PTC in the evaluation of neck or mediastinal lesions.