Dedifferentiated Chondrosarcoma of Temporomandibular Joint: Atypical Features of a Rare Case

Abstract

A 55-year-male patient visited our dental outpatient department with a complaint of pain and progressive swelling on right side of the face since six months. Extra oral examination revealed a diffuse preauricular swelling measuring about 5x3 cm. On palpation it was firm, tender, diffuse and fixed to underlying structures. Right submandibular nodes were palpable, non tender and mobile. There was restricted mouth opening with 18mm of inter incisal distance with spontaneous deviation of the jaw to affected side on opening the mouth [Table /Fig-1a,b]. There was no history of recent or past trauma to the area. Clinically, the provisional diagnosis included chronic inflammation or tumour of the TMJ, fracture of the condyle, sialadenitis or tumour of the parotid gland. However, the salivary duct opening and salivary flow were normal.Coronal and axial CT scan revealed an ill defined osseous outgrowth arising from right condyle of mandible showing bony destruction and deformity with soft tissue component and islands of amorphous calcification. The cortex of the lesion was seen destroyed, continuous with that of underlying bone from which it arose and the trabecular pattern was seen merging into the medullary cavity [Table/ Fig-2a,b]. The lesion involved the right infratemporal fossa, masticator space and eroded the posterior wall of the maxillary sinus. Such findings of a destructive lytic lesion that too of a short duration favored an underlying malignant process like osteosarcoma, chondrosarcoma or any metastatic tumour of TMJ. Fine needle aspiration cytology of the mass was performed which was non contributory. An incisional biopsy revealed neoplastic chondrocytes in lacunar spaces present in a chondroid matrix, exhibiting pleomorphic and hyper chromatic nucleus. A diagnosis of chondrosarcoma (CS) was made but possibility of chondroblastic osteosarcoma was kept in mind as it was a small biopsy specimen. Investigations like chest radiographs, ultrasound of neck and abdomen and CT of neck were done to rule out metastasis. Segmental resection of ramus was done along with excision of tumour mass that measured about 10 x7 cm. The condyle was resorbed and cut surface of tumour was whitish opaque, peripherally slightly mucoid and with central foci of calcifications [Table /Fig-3a,b]. Microscopically the sections showed typical low grade cartilaginous matrix and pleomorphic chondrocytes in large lacuna with hyperchromatic nuclei and open chromatin pattern, arranged in a lobular configuration. This sharply contrasted the adjacent foci made of pleomorphic spindle cells in storiform pattern Fig-4a,b]. There were foci of enchondral ossification. No presence of tumour osteoid could be discerned in multiple, serial sections. A final diagnosis of dedifferentiated chondrosarcoma of right TMJ was made. The surgical margins of resected specimen were free of tumour infiltration. On advice of the medical oncologist, the patient received radiotherapy one month post-operatively and remained in a one year disease free follow-up.

Imaging features of chondrosarcoma of the temporomandibular joint: report of nine cases and literature review

“…In the literature review cases, metastasis to the lung was found in only one case 1 year after the surgery. 8 All 40 patients reviewed in Table 3 were treated by surgical excision, with adjuvant radiotherapy in eight cases, 4,6,7,9,15,31,38,41 and adjuvant chemoradiotherapy in one case. 23 There were two cases of recurrence.…”

Dedifferentiated Chondrosarcoma of the Larynx: A Case Report and Review of the Literature

“…It is also recommended that patients with laryngeal DC receive adjuvant radiotherapy [2]. Although in this case, the patient received adjuvant radiation therapy, there have been previously reported cases in the literature in which the patient did not receive adjuvant therapy following surgical excision [5,17]. The role of radiation therapy remains undetermined [4].…”

“…Histological analysis remains the goldstandard for diagnostic purposes [3,6,10]. The histopathologic hallmark of DC concluded in case studies is the presence of an abrupt transition between low grade cartilaginous component juxtaposed on a high-grade, noncartilaginous, spindle cell sarcoma with pleomorphism, vesicular nuclei, giant cells, and numerous mitoses [4,5,9,10,13,18,23]. The cartilaginous portion of the tumor can contain some cells of DC, and thus the entire tumor must be examined.…”

“…CS, as a whole, is relatively common [1][2][3][4]. These tumors are most commonly located in the pelvis, femur, ribs, humerus, scapula, fibula, sacrum, or sternum; accounting for about 10-20% of malignant primary bone tumors [1][2][3][5][6][7][8]. Paranasal sinuses, nasal cavity, temporal bone, mandible and larynx were the most common sites of head and neck chondrosarcomas origin [9].…”