Cartilaginous hamartoma

These are benign neoplasms composed of a mixture of cartilage, fat, and fibromyxoid tissue. This circumscribed nodule, 1.5 cm in diameter, has the pearly appearance of cartilage. The glistening, translucent, cyst-like area is the fibromyxoid tissue.

The tumor is sharply circumscribed and surrounded by normal lung (bottom). Cartilage lies to the right, and lobules of fibromyxoid tissue to the left are covered by non-neoplastic respiratory epithelium (arrow). Diagnosis by fine needle aspiration requires finding fibromyxoid tissue or cartilage.

See also Case 21

Laryngeal papilloma

Laryngotracheal papillomas are benign tumors covered by non-keratinizing, squamous epithelium. Solitary or multiple, they are caused by human papillomaviruses. Often recurrent, malignant transformation sometimes ensues. Paranuclear, viropathic vacuolation may be seen at high magnification.

See also Case 8