Extraskeletal Myxoid Chondrosarcoma of the Jugular Foramen in a Pediatric Patient: A Case Report and Comprehensive Review of the Literature

Chondrosarcomas are malignancies that usually occur in the central part of large bones, such as the femur, pelvis, humerus, scapula, and ribs [1, 2]. They constitute approximately 11% of all malignant primary bone tumors [1, 3]. Intracranial involvement of chondrosarcomas is rare and accounts for 0.15% of all intracranial tumors and 6% of all skull base tumors [3‒5]. Intracranial chondrosarcomas are usually located at the anterior skull base, maxillary sinus, ethmoid sinus, sella turcica, and nasal cavity [2, 3, 5]. The jugular foramen is an unusual location of chondrosarcomas. Chondrosarcomas are more frequent in the fifth and sixth decades of life but not in the pediatric population. Herein, we report a case of a 14-year-old female patient with extraskeletal myxoid chondrosarcoma of the jugular foramen and discuss the relevant literature.

A 14-year-old girl was admitted to our clinic with complaints of dysphonia, dysphagia, tinnitus, and diplopia for 2 months. She had no contributive medical history. She was conscious, and her pupils were equal and reactive to light. Involvement of left-sided abducens and lower cranial nerves was noted. She showed impaired gag reflex on the left side, deviation of the uvula to the right side, and left shoulder and sternocleidomastoid muscle weakness revealing Vernet’s (jugular foramen) syndrome.

Brain magnetic resonance imaging (MRI) revealed a mass lesion measuring 28 × 30 × 27 mm at the left-sided cerebellopontine angle cistern and jugular foramen (Fig. 1). The mass was hypointense on T1-weighted images and hyperintense on T2-weighted images and showed heterogeneous contrast enhancement with gadolinium administration (Fig. 1). Compression on the brainstem and cerebellar peduncle was noted.

Tumor resection was planned for relieving brainstem and cranial nerve compression as well as for histopathologic sampling. Gross total resection (GTR) of the tumor was performed via left-sided retrosigmoid approach. The tumoral portion in the jugular foramen was also resected. Bone destruction and enlargement of the left-sided jugular foramen were detected on postoperative brain computed tomography (Fig. 2a–c). Histopathological examination of the samples revealed myxoid, chondroid tumor cells with eosinophilic cytoplasms, and nodular growth pattern (Fig. 3a–c). Immunohistochemical staining was negative for brachyury and keratin (Fig. 3d, e). However, S100 protein was positive (Fig. 3f), and the tumor was diagnosed as extraskeletal myxoid chondrosarcoma.

The postoperative course of the patient was uneventful, and her complaints improved. In the third month after surgery, contrast-enhanced brain MRI did not reveal any residual or recurrent lesion (Fig. 2d–f). Moreover, she presented no recurrence or new complaints at the 15-month follow-up.

Intracranial chondrosarcomas are rare clinical entities. They are classified as primary and secondary chondrosarcomas. Primary chondrosarcomas include conventional, dedifferentiated, clear cell, mesenchymal, and myxoid chondrosarcomas, while secondary chondrosarcomas develop from benign cartilage lesions, including osteochondroma, enchondroma, multiple hereditary exostosis, Ollier’s disease, and Maffucci’s syndrome [2, 5, 6]. In 1999, Rosenberg et al. [7] classified chondrosarcomas into three grades based on histopathological features: well differentiated (grade 1), moderately differentiated (grade 2), and poorly differentiated (grade 3). Most chondrosarcomas belong to the conventional subtypes and are usually grades 1 and 2. Dedifferentiated, clear cell, and mesenchymal chondrosarcomas are more aggressive and constitute less than 10% of all skull base chondrosarcomas [5, 8]. Myxoid chondrosarcomas originate from the soft tissues of long bones, especially from the lower extremities. They are rarely found intracranially and in the pediatric population [9, 10]. Myxoid chondrosarcomas are slow-growing tumors with tendency of recurring locally [2, 10].

Establishing the differential diagnosis of jugular foramen tumors is quite challenging. Primary tumors, including glomus jugular tumors, schwannomas, meningiomas, peripheral primitive neuroectodermal tumors, and secondary tumors including chordomas, chondrosarcomas, chondroblastomas, giant cell tumors, temporal bone metastases, can invade the jugular foramen [11, 12]. Chondrosarcomas are extradural or intradural, laterally located lesions frequently associated with erosive and destructive bone changes, entrapped bony trabeculae, areas of necrosis, and recent or old hemorrhages on radiological scans [12, 13]. Brain computed tomography scans reveal bone destruction and tumor calcifications. Chondrosarcomas are hypointense on T1-weighted images and hyperintense on T2-weighted images and show heterogeneous contrast enhancement with gadolinium on brain MRI [5, 10, 12].

The primary objective in the treatment of intracranial chondrosarcomas is GTR of the tumor [2, 5, 9, 14]. However, total resection is not always possible because of their proximity to cranial nerves, important vascular structures, and eloquent brain areas such as the brainstem [1, 4]. Adjuvant treatments including fractionated radiotherapy, stereotactic radiosurgery, or proton beam radiotherapy should be administered to patients with high-grade diseases or in whom total tumor resection cannot be achieved [3‒5, 10, 11, 14, 15]. The application of chemotherapy is a controversial topic, and no widely accepted chemotherapy regimen for these tumors has been reported in the literature [5, 10, 15].

According to our literature review, chondrosarcomas of the jugular foramen are rare tumors, especially the myxoid subtype. Moreover, only 11 cases of jugular foramen chondrosarcomas have been reported so far (Table 1). The present case is the second case of the myxoid subtype and the second in the pediatric population. However, to the best of our knowledge, she is the first pediatric patient with a myxoid chondrosarcoma of the jugular foramen (Table 1).

Extraskeletal myxoid chondrosarcomas of the jugular foramen are rare tumors, especially in the pediatric population. Because of their slow-growing nature and tendency for local recurrence, GTR of the tumors should be the aim of the treatment. However, adjuvant methods such as radiotherapy should be additionally applied in patients with high-grade diseases or those in whom total tumor resection cannot be achieved.

Preparation for publication of this article is partly supported by the Turkish Neurosurgical Society.

The authors state that the research complies with the guidelines for human studies, and the research was conducted ethically in accordance with the World Medical Association Declaration of Helsinki. Ethical approval was not required for this study in accordance with national guidelines. The authors state that the father of the patient has given their written informed consent for publication of data and images.

The authors report no conflicts of interest concerning the materials or methods used in this study or the findings specified in this paper.

The authors did not receive any funding.

Kadir Oktay and Tahsin Erman were involved with the conception and design; acquisition, analysis, and interpretation of data; drafting; revising; and final approval of the manuscript. Araz Aliyev, Halil Emre Alcan, Kerem Mazhar Ozsoy, and Nuri Eralp Cetinalp were involved with the acquisition, analysis, and interpretation of data and revising the manuscript. Seyda Erdogan was involved with the acquisition, analysis, and interpretation of data.

Data cannot be shared for confidentiality reasons. Queries about the data should be directed to the corresponding author.