Chondrosarcoma

Chondrosarcomas are uncommon tumors, Those that originate in the head and neck account for approximately 10 to 15% of all cases. Chondrosarcomas of the nasal septum are rare; only 55 such cases have been reported.

Most chondrosarcomas exhibit an indolent growth pattern. Nasoseptal tumors may mimic common sinonasal conditions, making early diagnosis difficult. Yet despite late identification, disease is often localized, and skull base and cranial nerve involvement have been reported to occur in only 22% of cases.

We report a rare case of nasoseptal chondrosarcoma that was all the more atypical in that it was characterized by an aggressive growth pattern and widely disseminated craniofacial disease. To our knowledge, such an aggressive course has not been previously reported.

A 56-year-old Hispanic man with a recent history of myocardial infarction was referred to the otolaryngology service with a 3-month history of bilateral nasal obstruction and an osmia that had not responded to medical therapy. He also complained of a recent visual disturbance in his left eye.

An endoscopic nasal examination revealed that large, smooth, bilateral nasal masses had arisen adjacent to the posterior septum and had obstructed both choanae (figure 1). The patient's visual acuity was significantly reduced on the left. Findings on the remainder of the head and neck examination were unremarkable.

[FIGURE 1 OMITTED]

Axial magnetic resonance imaging (MRI) detected a large hypodense mass that was located at the posterior nasal septum (figure 2). The mass featured multiple areas of calcification, and it extended bilaterally to the lateral nasal walls and to the ethmoid and sphenoid sinuses. It also compressed the left medial orbital wall. Gadolinium-enhanced MRIs reflected low-intensity signals oil T1-weighted imaging and high-intensity signals on T2-weighted imaging (figure 3). MRI also showed that the mass had displaced the left internal carotid artery and invaded the anterior skull base and clivus.

[FIGURE 2 OMITTED]

Within 1 week of our initial evaluation, the patient's visual disturbance in the left eye progressed to complete blindness. Treatment with high-dose steroids resulted in return of light perception. In view of how rapidly the patient's symptoms had progressed, we conceded that it was unlikely that we would be able to achieve a complete surgical resection. In fact, after a multidisciplinary (ophthalmology, neurosurgery, and otolaryngology) evaluation, we concluded that the prognosis was poor regardless of treatment. We initially considered deferring any aggressive intervention in view of the extent of clival infiltration, even though the presumed natural progression of this tumor would likely lead to brainstem instability and bilateral blindness. Nevertheless, we decided to offer the patient palliative (albeit significant) surgery. However, he refused the offer because he was fearful of the degree of surgical invasiveness and the risk of complications.

One week later, however, the patient returned complaining of blurred vision in his right eye. Fearful that he would become completely blind and now wishing to delay any potential brainstem sequela, he agreed to undergo palliative surgery. The goal of surgery was to alleviate symptoms by removing as much tumor as possible while minimizing functional and cosmetic morbidity. We chose a combined transpalatal-transcranial approach, which provides for wide surgical exposure, causes no functional morbidity, and does not require any facial incisions. Via this approach, we performed a bilateral ethmoidectomy, anterior skull base resection, sphenoidectomy, subtotal septectomy, partial palatectomy, and nasopharyngectomy. We reconstructed the anterior skull base with a pericranial flap opposed with a split-thickness skin graft.

On gross examination, the excised 8 x 8 x 8-cm, pearlgray, solid tumor exhibited cartilaginous features. Histologic analysis revealed that clusters of multinucleated cells with enlarged vesicular hyperchromatic nuclei and very few mitoses were embedded in a lobular chondroid stroma; these findings were consistent with a grade II chondrosarcoma. The tumor margin was positive for residual disease at the clivus.

The patient experienced no peri- or postoperative complications, and he was discharged on postoperative day 7. He received postoperative chemoradiation. At the 6-month follow-up, he exhibited no clinical evidence of nasal disease, his visual acuity was stable with normal vision in the right eye, and he denied any nasal obstruction or new neurologic deficits. He showed no evidence of disease progression on MRI 1 year posttreatment.

Most head and neck chondrosarcomas arise in the maxilla and mandible. Most of the previously reported cases of nasoseptal chondrosarcomas occurred during the fourth and fifth decades of life; men and women were equally affected.

Chondrosarcomas can arise from cartilage, embryonic rests, or mesenchyreal cells that undergo multidirectional differentiation. Based on their cells of origin, they can be classified as one of three types--primary, secondary, or mesenchymal:

* Primary chondrosarcomas arise from undifferentiated perichondrial cells.

* Secondary chondrosarcomas originate in transformed cells from a central chondroma or cartilaginous exostosis.

* Mesenchymal chondrosarcomas develop in primitive mesenchymal cells.

Chondrosarcomas are graded histiologically according to their degree of cellularity, atypia, mitotic activity, nuclear size, and surrounding matrix composition. Grade I tumors have an ample chondroid matrix with scattered clusters of chondrocytes with near-normal nuclei and no mitotic figures. Grade II tumors display a higher degree of cellularity with a less-chondroid matrix, increased mitotic figures, multinucleation, and hyperchromatic vesicular nuclei. Grade III tumors are characterized by irregularly shaped chondrocytes in a myxoid matrix and increased nuclear pleomorphism.

Imaging studies reveal characteristic findings. Computed tomography (CT) demonstrates a low-density matrix with speckled calcifications and bony erosion. MRI helps delineate the full extent of the soft tissue, typically demonstrating low intensity on T1-weighted imaging, high intensity on T2-weighted imaging, and heterogenous enhancement with gadolinium contrast. Radiographic differential diagnoses include chondroma, osteoblastoma, osteochondroma, meningioma, and fibro-osseous lesions.

Chondrosarcomas are generally slowly growing malignancies. Their gradual progression allows for relatively asymptomatic growth, which typically leads to a late diagnosis. This unfortunately can result in extensive loco-regional infiltration prior to diagnosis. In cases where the lesion breaches the cranial vault, the extent of involvement usually remains extramural and is limited to the anterior cranial fossa. The clinical presentation depends on the site of origin and the extent of local disease. Patients whose tumors involve the sinonasal area often present with nasal obstruction of 1 year's duration. Less common complaints include headache, epistaxis, anosmia, cranial nerve palsy, and various visual disturbances.

Complete surgical resection is the treatment of choice; incomplete resections are associated with a 65% recurrence rate. Radiation and chemotherapy are reserved for recurrences and for cases of incomplete extirpation. Although total resection improves outcomes, surgical treatment may prove to be difficult in cases of extensive local disease.

Several points of interest are noted in this case: the rarity of the disease, the atypically rapid disease progression, and the indication for palliative surgery despite wide local disease in an effort to preserve vision and improve the patient's quality of life.

Suggested reading

Burkey BB, Hoffman HT, Baker SR, et al. Chondrosarcoma of the head and neck. Laryngoscope 1990; 100:1301-5.

Hug EB, Loredo LN, Slater JD, et al. Proton radiation therapy for chordomas and chondrosarcomas of the skull base. J Neurosurg 1999:91:432-9.

Rassekh CH, Nuss DW, Kapadia SB, et al. Chondrosarcoma of the nasal septum: Skull base imaging and clinicopathologic correlation. Otolaryngol Head Neck Surg 1996; I 15:29-37.

Ruark DS. Schlehaider UK, Shah JP. Chondrosarcomas of the head and neck. World J Surg 1992;16:1010-15, discussion 1015-16.

Saito K, Unni KK, Wollan PC, Lund BA. Chondrosarcoma of the jaw and facial bones. Cancer 1995:76:1550-8.

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