A Parapharyngeal Soft Tissue Chordoma Presenting with Synchronous Cervical Lymph Node Metastasis: An Unusual Presentation

Proton or Carbon Ion Therapy for Skull Base Chordoma: Rationale and First Analysis of a Mono-Institutional Experience

Background: Skull base chordomas are radio-resistant tumors that require high-dose, high-precision radiotherapy, as can be delivered by particle therapy (protons and carbon ions). We performed a first clinical outcome analysis of particle therapy based on the initial 4-years of operation. Methods: Between August 2017 and October 2021, 44 patients were treated with proton (89%) or carbon ion therapy (11%). Prior gross total resection had been performed in 21% of lesions, subtotal resection in 57%, biopsy in 12% and decompression in 10%. The average prescription dose was 75.2 Gy RBE in 37 fractions for protons and 66 Gy RBE in 22 fractions for carbon ions. Results: At a median follow-up of 34.3 months (range: 1–55), 2-, and 3-year actuarial local control rates were 95.5% and 90.9%, respectively. The 2-, and 3-year overall and progression-free survival rates were 97.7%, 93.2%, 95.5% and 90.9%, respectively. The tumor volume at the time of particle therapy was highly predictive of local failure (p < 0.01), and currently, there is 100% local control in patients with tumors < 49 cc. No grade ≥3 toxicities were observed. There was no significant difference in outcome or side effect profile seen for proton versus carbon ion therapy. Five patients (11.4%) experienced transient grade ≤2 radiation-induced brain changes. Conclusions: The first analysis suggests the safety and efficacy of proton and carbon ion therapy at our center. The excellent control of small to mid-size chordomas underlines the effectiveness of particle therapy and importance of upfront maximum debulking of large lesions.

Chordoma: analysis of 47 fine-needle aspiration biopsy, cytologic imprint, and small biopsy specimens

INTRODUCTION

Fine-needle aspiration (FNA) and small tissue biopsy of chordoma have been reported in several small series, but no large series exists. We undertook an examination of 47 cases (with concurrent core needle biopsy in a subset) to analyze diagnostic accuracy, cytomorphology, and immunohistochemistry.

MATERIALS AND METHODS

Our cytopathology files were searched for examples of chordoma with histopathologic verification. FNA biopsy smears and core needle were performed using standard techniques.

RESULTS

Forty-seven cases of chordoma were retrieved from 44 patients [M:F; 1.8:1; age range 5-81 years; mean age 55 years]. Twenty-seven presented with primary, 10 with locally recurrent, and 7 with metastatic tumors. Two aspirates were from the appendicular skeleton, 2 from the trunk, 1 from neck lymph node, and 42 aspirates (89%) from axial and peri-axial skeleton and surrounding soft tissues. Four were cytologic touch imprints while the remainder were FNA biopsy specimens. Specific cytologic diagnoses were chordoma/consistent with chordoma (44 cases, 94%), suspicious for chordoma (2), and malignant neoplasm (1). Along with a single case of benign notochordal tumor misdiagnosed as chordoma, our diagnostic accuracy was 91%. Concurrent tissue biopsy was performed in 51% of cases. Immunohistochemical staining of tumor in 29 (62%) cases showed expression of brachyury in 23 of 24 (96%) instances. Cytopathology consisted of cellular smears populated by large cells possessing enormous amounts of vacuolated and non-vacuolated cytoplasm with an abundant background myxoid/chondromyxoid stroma.

CONCLUSIONS

FNA and small tissue biopsy specimens show a very high degree of diagnostic accuracy in recognition of chordoma.

Soft Tissue Special Issue: Chondroid Neoplasms of the Skull

Clinically, radiologically, and pathologically, chondroid neoplasms of the skull can be diagnostically challenging due to overlapping features in each of these domains. Compounding the problem for the pathologist, there is also significant morphologic, immunophenotypic, and molecular genetic overlap between benign and malignant cartilaginous lesions, and the majority of these lesions are encountered quite rarely in routine surgical pathology practice. Each of these factors contribute to the diagnostic difficulty posed by these lesions, highlighting the importance of radiologic-pathologic correlation in the diagnosis. This review is intended to provide an update for surgical pathologists on some of the most commonly encountered chondroid neoplasms in the skull, and includes the following lesions: chondromyxoid fibroma, synovial chondromatosis, chondrosarcoma and variants, and chordoma and variants. For each of these lesions, the differential diagnosis and useful ancillary tests will be discussed in the context of a broad range of additional primary and secondary lesions.

Surgical Resection and Adjuvant Radiation Therapy in the Treatment of Skull Base Chordomas

OBJECTIVE

Chordomas are rare tumors of notochordal origin that are known to be locally aggressive and are often treated with surgical resection followed by adjuvant radiation therapy (RT). The accepted standard of treatment for chordomas of the mobile spine, which includes en-bloc resection with wide margins, cannot be easily applied to the chordomas of the skull base because of their proximity to critical neurovascular structures. We describe our experience with the role of surgery and adjuvant RT in the treatment of chordomas over 16 years.

METHODS

We performed a retrospective chart review on patients with diagnoses of clival chordoma between the years 2000 and 2015 at Northwestern Memorial Hospital. We reviewed presenting symptoms, tumor location and size, extent of resection, complications, recurrence, adjuvant treatment, and follow-up duration.

RESULTS

A total of 20 patients underwent 32 surgeries. Of the 20 initial surgeries, 80% underwent gross total resection, and 20% had subtotal resection. The mean follow-up time was 60.75 months. Mean tumor volume was 23.07 cm³. Most common presenting signs and symptoms were headaches (70%), cranial nerve palsies (45%), and diplopia (55%). Diplopia was defined as complaints of double vision without any objective evidence of a cranial nerve palsy. Median time to progression was 57 months, and median overall survival was 136 months. Initial tumor volume and the need for a second dose of RT either as sole or as adjuvant treatment of a recurrence had a statistically significant effect on progression-free survival (P = 0.009, 0.009). None of the factors studied had a statistically significant effect on overall survival.

CONCLUSIONS

The treatment of chordomas remain challenging and requires multimodal treatment strategies spanning different specialties. Initial tumor size and need for second dose of RT for recurrence appear to play a significant role in progression-free survival. Adjuvant RT after gross total resection may play a role in improved progression-free and overall survival in patients with clival chordomas.

Immunophenotypic features of dedifferentiated skull base chordoma: An insight into the intratumoural heterogeneity

Chordomas are rare and low-grade malignant solid tumours, despite their histologically benign appearance, that arise in the bone from embryonic notochordal vestiges of the axial skeleton, a mesoderm-derived structure that is involved in the process of neurulation and embryonic development. Chordomas occurring in the skull base tend to arise in the basiocciput along the clivus. Three major morphological variants have been described (classical, chondroid, and atypical/dedifferentiated). The pathogenesis and molecular mechanisms involved in chordoma development remain uncertain. From a pathological standpoint, the microenvironment of a chordoma is heterogeneous, showing a dual epithelial-mesenchymal differentiation. These tumours are characterised by slow modality of biologic growth, local recurrence, low incidence of metastasis rates, and cancer stem cell (CSC) phenotype. The main molecular findings are connected with brachyury immunoexpression and activation of the downstream Akt and mTOR signalling pathways. The differentiation between typical and atypical chordomas is relevant because the tumoural microenvironment and prognosis are partially different. This review provides an insight into the recent and relevant concepts and histochemical markers expressed in chordomas, with special emphasis on dedifferentiated chordomas and their prognostic implications.

An unusual case of oropharyngeal chordoma: A case report and literature review

RATIONALE

Chordomas are rare malignant neoplasms derived from incomplete regression of notochordal tissue along the cranio-coccygeal axis. Chordomas that develop in an atypical position are called ectopic chordomas, such as oropharyngeal chordomas (OCs). OCs are exceedingly rare; only 11 cases have been reported to date. Preoperative diagnosis is challenging, and an accurate diagnosis thus is based on postoperative pathologic examination findings and immunohistochemistry. Although surgical therapy and radiotherapy is performed in some patients, the 5-year survival rate is low. Increasingly more studies of chordomas have been based on molecular biology to increase the survival rate, and targeted therapy could be a new therapy in the future.

PATIENT CONCERNS

The patient presented with a left oropharyngeal mass that had begun slowly enlarging 1 year previously. He reported a foreign body sensation and dysphonia during this time period.

DIAGNOSES

The patient was initially diagnosed with a neurogenic tumor. Routine postoperative pathology showed that the mass was consistent with a chordoma.

INTERVENTION

Mass resection was performed.

OUTCOME

One year after the initial surgery, magnetic resonance imaging revealed block signal images at the left retropharyngeal space and clivus. The patient developed recurrence of the OC.

LESSONS

Surgical resection is the mainstay of treatment for OC, and postoperative adjuvant radiotherapy is also important. An understanding of the unusual case described in this report may be helpful in diagnosing OC, and development of targeted therapy may help clinicians to provide novel treatment for patients with OC.

Endoscopic Approach to Clival Chordomas: The Northwestern Experience

INTRODUCTION

Chordomas are rare primary bone tumors with a low-grade histology but an aggressive clinical behavior characterized by local invasion and recurrence. When occurring in the skull base, their treatment is limited by proximity to critical neurovascular structures. Open surgical approaches can carry high morbidity, making the development of alternative approaches desirable. We describe our experience with endoscopic endonasal approaches to clival chordomas over 13 years.

METHODS

We performed a retrospective chart review of patients diagnosed with clival chordomas and treated with an endoscopic endonasal approach between 2003 and 2015 at Northwestern Memorial Hospital. We reviewed presenting symptoms, tumor location and size, extent of resection, complications, recurrence, adjuvant treatment, retreatment, and follow-up duration.

RESULTS

A total of 23 charts were reviewed, with 17 included in our final review. Mean age was approximately 48 years. The most common presenting symptom was diplopia present in 70.6% of patients. Mean tumor volume was 20.2 cm³. Gross total resection was achieved in 52.9% of patients. With a mean follow-up period of 63.4 months, 5 patients had a recurrence. The most common complication was cerebrospinal fluid (CSF) leak, which was noted in 6 patients. Tumor volume was significantly higher in patients with CSF leak. No correlation between intradural extension and postoperative CSF leak was noted.

CONCLUSIONS

Clival chordoma are challenging entities to treat. The best outcomes are achieved with gross total resection followed by adjuvant radiotherapy treatment. We show that the endonasal endoscopic corridor is a viable alternative approach to these lesions.

Chordoma of the Head and Neck: A Review

Chordoma is a rare malignant bone tumor that can arise anywhere along the central neural axis and many involve head and neck sites, most commonly the skull base. The relative rarity of these tumors, combined with the complex anatomy of the head and neck, pose diagnostic challenges to pathologists. This article describes the pertinent clinical, pathologic, and molecular features of chordomas and describes how these features can be used to aid in formulating a differential diagnosis. Emphasis is placed on key diagnostic pitfalls and the importance of incorporating immunohistochemical information into the diagnosis.

Distinctive Head and Neck Bone and Soft Tissue Neoplasms

Benign and malignant primary bone and soft tissue lesions of the head and neck are rare. The uncommon nature of these tumors, combined with the complex anatomy of the head and neck, pose diagnostic challenges to pathologists. This article describes the pertinent clinical, radiographic, and pathologic features of selected bone and soft tissue tumors involving the head and neck region, including angiofibroma, glomangiopericytoma, rhabdomyosarcoma, biphenotypic sinonasal sarcoma, chordoma, chondrosarcoma, and osteosarcoma. Emphasis is placed on key diagnostic pitfalls, differential diagnosis, and the importance of correlating clinical and radiographic information, particularly for tumors involving bone.