A54-year-old man with a chronic cough has a squamous cell carcinoma diagnosed in his right lung. While performing a pneumonectomy, the thoracic surgeon notes that the hilar lymph nodes are small, 0.5 to 1.0 cm in size, and jet black in color throughout.
Which of the following is the most likely cause for this appearance to the hilar nodes?
A Anthracotic pigmentation
B Lipochrome deposition
C Accumulation of melanin
E Metastatic carcinoma
Answer / Explanation:
The black color comes from carbon pigments inhaled over the years, engulfed by macrophages, and sent via lymphatics to the nodes. It looks bad but does not compromise lung function.[/HIDE]