Objectives: To recall the common clinical presenting features of and guide the diagnostic procedures of primary thyroid lymphomas (PTL). Materials and methods: We report on three patients developing an acute dyspnoea and fast evolving neck mass in thethyroid caused by a PTL occurring in our regional hospital in Switzerland between 2009 and 2013.Results: PTL causes a neck mass, dyspnoea and dysphonia and responds well to chemotherapy. Mortality is due to relapse or infectious complications. Conclusion:Acute dyspnoea caused by thyroid disease is uncommon. Nevertheless, it is the main symptom in PTL due to rapid growth and compression of the airways. Chemotherapy should be started promptly.