Teaching Case

A 68-year-old woman presented with a two-year history of cough and progressive dyspnoea. She reported intermittent dysphonia and stridor episodes since one year. She denied smoking and other relevant aerodigestive tract diseases. Spirometry revealed variable upper airway obstruction. Nasopharyngolaryngoscopy showed a subglottic lesion, occupying the left glottic cleft (Fig. 1).

Contrast-enhanced neck computed tomography (CT) revealed a 13x14x15mm solid and heterogeneous nodular lesion, in subglottic topography and arising from the left side of the cricoid cartilage, composed by apparent chondroid material, with punctiform calcifications inside. The lesion did not involve the left arytenoid, however. It induced superior dislocation of the homolateral vocal cord and caused obliteration of the air column, which was frankly reduced to this level, although permeable (Fig. 2).
Neck magnetic resonance imaging (MRI) was also performed, which showed a nodular lesion, in the posteromedial aspect of the cricoid cartilage. It was isointense on T1-weighted sequences, hyperintense on T2, with moderate enhancement after paramagnetic contrast administration and with intra-lesional hyposignal foci, suggesting calcifications (Fig. 3). No signs of diffusion restriction were visible (Fig. 4).

After imaging, the patient underwent laryngeal microsurgery.

Laryngeal chondrosarcoma is a rare entity with a slow-growth pattern, accounting for 0.07% to 2% of all laryngeal neoplasms. [1-4]
It‘s rarely found in the head and neck region (10-12%) and is most commonly located in the pelvis, long bones, sternum, and ribs. [1] In the larynx, it‘s usually seen in males, with a male-to-female ratio of 3:1. [5] The average age at diagnosis is 60 to 64 years. [1,3-5]
The most common location in the larynx is the cricoid cartilage (75%), especially in the posterior lamina, although it may emerge from the thyroid (17%), arytenoid (5%), and epiglottis and accessory cartilages (3%). [1-5]
Its aetiology remains unclear; however, it appears to result from primary disordered ossification of the cartilages. [1-5]
Symptoms depend on the size and location of the tumour. [1-3] Patients may present with hoarseness, dyspnoea, dysphagia, dysphonia, stridor, and neck mass complaints, or may be asymptomatic. [1-6]
Imaging plays an essential diagnostic role; however, the distinction between chondroma and low-grade chondrosarcoma is unreliable. [2,3] Local invasion and lymph node metastases are most often seen in high-grade chondrosarcoma. [2]
CT is the imaging modality of choice. [3,4,6] It typically demonstrates a well-circumscribed hypodense lesion that, in 75% of cases, contains multiple ring-like or popcorn calcifications. [1,2,4-6] Moderate enhancement can be observed. [4]
MRI with contrast has greater sensitivity when assessing the relationship of the tumour to parapharyngeal tissues. [3] The lesion is usually isointense on T1-weighted sequences and hyperintense on T2. [2,4,5]
Chondrosarcomas are classified into three histological groups based on cellularity, atypia, and pleomorphism: low (I), intermediate (II), and high (III). [2,6] Most laryngeal chondrosarcomas are detected in grades I and II. [1] Some authors reserve the diagnosis of chondroma for lesions smaller than 1 cm without cellular atypia. [4,5]
Conservative surgery with preservation of the laryngeal structure and function is the treatment of choice for low-grade tumours; total laryngectomy should be preferred for high-grade tumours and recurrences. [2,4]
Low-grade chondrosarcoma does not respond to chemotherapy, which probably reflects its slow growth rate. [2,4,6] The effectiveness of radiotherapy is controversial; however, it may play a role in treating recurrences, or extensive and high-grade lesions. [4]
Laryngeal chondrosarcoma has a good long-term prognosis, with a 10-year survival rate of 95%. [1,4] Pulmonary, bone, and liver metastasis can be seen, although they are rare (10%). [2-4]
Recurrence is frequent, occurring in 18% to 40% of cases [1,4], but mortality due to laryngeal chondrosarcoma is rare. [2]

Histopathological examination confirmed low-grade chondrosarcoma.

Written informed patient consent for publication has been obtained.