BENIGN LARYNGEAL TUMOURS 175 2. Pyogenic Granuloma. This can occur anywhere in the head and neck region and often resembles a carcinoma. It is basically an infected granuloma and it does not recur after adequate local removal. Bleeding and ulceration also occur. 3. Granuloma Gravidarum. This is a pyogenic granuloma occurring during pregnancy. It is better to leave it alone until the pregnancy is over. GRANULAR-CELL MYOBLASTOMA This has a characteristic histological appearance of pseudo-epitheliomatous hyperplasia. The tumour is always sessile and can usually be removed totally at direct laryngoscopy. It is now believed that it is not a malignant or a pre- malignant tumour. CHONDROMA This is a rare tumour affecting almost exclusively the cricoid cartilage. It is very slow growing and presents a smooth swelling which encroaches into the lumen of the larynx (Fig. 79). Occasionally the difference between benign Fig. 79. Tomograph of larynx of a man, aged 70 years, with a chondrosarcoma of thyroid cartilage showing considerable narrowing of the airway. chondroma and chondrosarcoma is difficult to make. If the diagnosis is made early and if local removal can be accomplished while preserving the ring of the cricoid cartilage the condition may be kept under control, but if it is not possible to preserve the ring of the cricoid the condition is probably sarco- matous and a laryngectomy should be performed.