Myxoid chondrosarcoma of sphenoid bone

[Diagnosis and treatment of rare malignant temporal bone tumors]

Objective:To analyze the diagnosis, treatment and prognosis of patients with rare malignant tumors of the temporal bone. Methods:Four cases of rare temporal bone malignant tumors in our hospital between March 2014 and December 2020 were reviewed, including two cases of chondrosarcoma, one case of fibrosarcoma and one case of endolymphatic cystic papillary adenocarcinoma. There were three males and one female, ages between 28 and 56 years at the time of surgery. Common symptoms included hearing loss, facioplegia, tinnitus, and headache. All patients underwent imaging examinations to evaluate the extent of the lesions. Tumors were removed by subtotal temporal bone resection or infratemporal fossa approach, and postoperative adjuvant radiotherapy was applied if necessary. Results:One of the two chondrosarcoma patients was cured by complete resection of the tumor for 75 months, the other one recurred after the first excision of the tumor and underwent infratemporal fossa approach resection of skull base mass again with no recurrence found yet for 112 months. One patient with fibrosarcoma survived for 28 months after surgery with a positive margin and post-operative radiotherapy. One patient with endolymphatic cystic papillary adenocarcinoma recurred 12 months after subtotal lithotomy, and underwent subtotal temporal bone resection again, combined with radiotherapy. No recurrence was found for 63 months. Conclusion:The incidence of rare temporal bone malignant tumors is extremely low, the location is hidden, and the symptoms are atypical. Attention should be paid for early detection and early treatment. Surgical resection is the main treatment, and radiotherapy can be supplemented in the advanced stage or with a positive margin.

Skull Base Parachordoma/Myoepithelioma

Parachordoma is a rare soft tissue mixed tumor, associated with soft tissue myoepithelioma. It is typically growing slowly and considered less aggressive than other similar soft tissue tumors. However, it does recur sporadically, and on rare occasions, it has demonstrated the ability to metastasize. Although imaging is important, definitive diagnosis is achieved by histology, and it is typically treated by a wide local excision. We present the first reported case of a skull base parachordoma in a 15-year-old boy, managed with a wide local excision and with no signs of recurrence or metastases after 24 months of follow-up.