A Second Primary Squamous Cell Carcinoma Arising in the Skin of a Pectoralis Major Myocutaneous Flap 20 Years after Tongue Reconstruction

A 54-year-old man presented with a second primary tongue squamous cell carcinoma, which developed in the pectoralis major myocutaneous flap used for the reconstruction of the right side of the tongue 20 years previously. The patient had originally undergone concurrent chemoradiotherapy and subtotal glossectomy. We believe that the carcinoma was likely caused by metaplastic transformation of the flap skin due to its chronic exposure to stimuli not normally experienced by the skin. The findings in this case suggest that patient education and long-term follow-up are required following flap reconstruction in cases of advanced oral cancer.