Recurrent skeletal extra-axial chordoma confirmed with brachyury: imaging features and review of the literature

Chordoma arising from the coccygeal disc and mimicking a pilonidal cyst

Chordomas are rare, low-grade malignant tumors often found in the sacrococcygeal region and prone to local recurrence. We report an atypical presentation of a 40-year-old patient with a symptomatic midline retrococcygeal lesion that was presumptively treated as a pilonidal cyst due to its clinical and imaging features. After surgical pathology rendered the diagnosis of chordoma, the patient required salvage surgery in the form of partial sacrectomy with soft tissue flap coverage. In addition to the unusually predominant retrococcygeal location, surgical pathology identified an intervertebral disc origin rather than the typical osseous origin. To our knowledge, this presentation of chordoma with coccygeal intervertebral origin and a large subcutaneous mass at imaging has rarely been reported in the literature. We describe this case to raise awareness of atypical presentations of sacrococcygeal chordoma that may lead to erroneous presumptive diagnosis and treatment.

Pediatric Extra-Axial Chordoma: Case Report and Literature Review

Extra-axial chordomas in the pediatric population are extremely rare and diagnostically challenging; only four cases have been previously reported with ages ranging from 13 to 20 years. We report a primary extra-axial chordoma involving the soft tissue directly dorsal and ulnar to proximal phalanx in the right thumb of a 12-year-old girl who presented with worsening right thumb pain for 1.5 years. The diagnosis was confirmed by excisional biopsy demonstrating proliferation of large, polygonal epithelioid cells with diffuse expression of pan-cytokeratin and brachyury. The patient required repeat excision for local recurrence seven months later. Since then, she has remained disease free through 15 months surveillance. Extra-axial chordomas share the same histopathological and immunohistochemical characteristics with their axial counterparts and should be considered in the differential diagnosis for any extra-axial bone or soft tissue mass with epithelioid morphology.

Recurrent loss of chromosome 22 and SMARCB1 deletion in extra-axial chordoma: A clinicopathological and molecular analysis

Extra-axial chordoma is a rare neoplasm of extra-axial skeleton and soft tissue that shares identical histomorphologic and immunophenotypic features with midline chordoma. While genetic changes in conventional chordoma have been well-studied, the genomic alterations of extra-axial chordoma have not been reported. It is well known that conventional chordoma is a tumor with predominantly non-random copy number alterations and low mutational burden. Herein we describe the clinicopathologic and genomic characteristics of six cases of extra-axial chordoma, with genome-wide high-resolution single nucleotide polymorphism array, fluorescence in situ hybridization and targeted next-generation sequencing (NGS) analysis. The patients presented at a mean age of 33 years (range: 21-54) with a female to male ratio of 5:1. Four cases were histologically conventional type, presented with bone lesions and three of them had local recurrence. Two cases were poorly differentiated chordomas, presented with intra-articular soft tissue masses and both developed distant metastases. All cases showed brachyury positivity and the two poorly differentiated chordomas showed in addition loss of INI-1 expression by immunohistochemical analysis. Three of four extra-axial conventional chordomas showed simple genome with loss of chromosome 22 or a heterozygous deletion of SMARCB1. Both poorly differentiated chordomas demonstrated a complex hyperdiploid genomic profile with gain of multiple chromosomes and homozygous deletion of SMARCB1. Our findings show that heterozygous deletion of SMARCB1 or the loss of chromosome 22 is a consistent abnormality in extra-axial chordoma and transformation to poorly differentiated chordoma is characterized by homozygous loss of SMARCB1 associated with genomic complexity and instability such as hyperdiploidy.

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.

Intra-articular extra-axial chordoma of the wrist: a case report with review of the current literature

Chordomas are rare bone malignancies that are thought to arise from remnants of the notochord and usually are located in the axial skeleton. Immunophenotypical matching neoplasms primarily found in appendicular locations, referred to as extra-axial chordoma, are rarely encountered by radiologists, surgeons, and pathologists. Only a few of these cases have been described in the literature with only one intra-articular case with involvement of the knee joint. We present the first case of an intra-articular extra-axial chordoma of the wrist. Diagnostic imaging patterns were initially ambiguous and histopathological reprocessing was crucial in order to determine the diagnosis of an intra-articular neoplasm with co-expression of cytokeratins, S-100 protein, and brachyury.

Extra-axial chordoma of the gingiva

BACKGROUND

Extra-axial chordomas are exceedingly rare malignant tumours. Herein, we present the first case of an extra-axial chordoma in the gingivae.

METHODS AND RESULTS

A 21-year-old man presented with a suspected chordoma in the upper right gingiva. Diagnosis was difficult; however, owing to strong expression of the chordoma marker brachyury, extra-axial chordoma was ultimately diagnosed. The tumour was completely resected without performing a facial incision. To ensure its safety and effectiveness, the surgical procedure was simulated several times before its performance using a three-dimensional (3D) model. Twenty-four months after surgery, the patient remains disease-free.

CONCLUSION

A diagnosis of extra-axial chordoma can be confirmed by immunohistochemical staining for brachyury.

Parosteal extra-axial chordoma of the second metacarpal bone: a case report with literature review

Extra-axial chordoma is a chordoma that occurs in non-axial locations. It is a very rare tumor, with 20 cases reported to date; 14 in bone and six in soft tissue. Of the 14 skeletal extra-axial chordomas, ten were intramedullary and four were intracortical. We report the first case of parosteal extra-axial chordoma arising in the second metacarpal bone, expressing brachyury on immunohistochemical analysis, and describe the pathologic and radiologic findings. We suggest that extra-axial chordoma can occur in parosteal bone lesions or the hand, without features of bone distribution or bone-specific sites.

Proximal tibial extra-axial chordoma masquerading as renal cell carcinoma metastasis

Chordomas are rare, locally aggressive notochordal tumors, which most frequently occur in the neuraxis. We describe the case of a 74-year-old male with a history of renal cell carcinoma, who presented with a slowly enlarging mass in his left leg. While the clinical history and imaging suggested metastatic renal cell carcinoma, immunohistochemical staining with brachyury ultimately made the diagnosis of extra-axial chordoma. At 74 years of age, our patient is the oldest ever reported with bony extra-axial chordoma objectively confirmed by brachyury staining. A detailed case discussion and a review of the available literature on this rare clinicopathologic entity are provided.

Extra-Axial Chordoma of the Hand

Chordomas are low-grade malignant tumors that are locally aggressive and have the potential to metastasize. They most often occur in the sacrococcygeal and spheno-occipital portions of the vertebral column. Morphologically similar tumors have been found outside the axial skeleton and are referred to as extra-axial chordomas. Several case reports have described the radiologic, microscopic, and immunologic profiles of these tumors and their similarities to axial chordomas. The authors report a 24-year-old man who presented with a mass in his left hand and underwent surgical excision. Specimens stained positive for pancytokeratin, S100, and brachyury. Brachyury is a protein that is present during embryogenesis and is expressed by chordomas. This is the first report of an extra-axial chordoma within the interosseous muscle compartment of the hand in a young patient.

Frequency and Risk Factors for Additional Lesions in the Axial Spine in Subjects With Chordoma: Indications for Screening

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

We aim to evaluate the frequency and clinical significance of additional lesions in the axial spine in subjects with chordoma and to assess the need for screening.

SUMMARY OF BACKGROUND DATA

Chordomas are rare tumors that may be multicentric or metastasize and affect several bones in the axial spine. The incidence of multiple lesions in the axial spine is unknown. Understanding the incidence rate of multiple lesions in the spine in subjects with chordomas will help guide utilization of total spine screening imaging.

METHODS

We performed a retrospective review of medical records of 42 subjects with histologically confirmed chordomas who had complete imaging of the axial spine. Lesions with imaging characteristics suggestive of chordomas/notochordal remnants were identified. Data on age at diagnosis, sex, size (in maximal dimension), type of chordoma (conventional, chondroid, or dedifferentiated), and whether pulmonary metastases were present were recorded. Binomial two-sample tests of proportions were used to compare proportions. Logistic regression was used to assess predictors of additional lesions.

RESULTS

Forty-two subjects (57.1% male) were identified. The proportion of subjects with additional lesions in the axial spine was 16.7% (7/42). Age, sex, size, and subtype of chordoma were not significant predictors of having additional lesions (P > 0.05 for each variable). However, having pulmonary metastases was a significant predictor of having additional lesions (P < 0.05).

CONCLUSION

Approximately 17% of subjects with chordomas had additional lesions in the axial spine. It is unclear whether these represent metastases, synchronous primary chordomas or notochordal remnant tissue. Screening imaging of the axial spine may reveal additional lesions in particular in subjects with pulmonary metastases.

LEVEL OF EVIDENCE

3.

Differences in sex distribution, anatomic location and MR imaging appearance of pediatric compared to adult chordomas

Background

Chordomas are rare malignancies that primarily affect adults, but also rarely affect pediatric patients. We compared the imaging appearance, demographic and anatomic distributions of adult and pediatric chordomas in a large cohort.

Methods

We performed a retrospective review of medical records of 220 subjects with histologically confirmed chordomas of the axial skeleton and pre-treatment magnetic resonance imaging studies. Age, sex, type of chordoma (conventional, chondroid or dedifferentiated), the anatomic location of the chordoma, as well as whether the lesion was primarily extra-osseous were recorded. Pediatric subjects were less than 21 years at the time of diagnosis. Binomial two-sample tests of proportions and Fisher’s exact tests were used to compare proportions between the pediatric and adult subjects.

Results

Fifty six pediatric subjects (58.9 % female) and 164 adult subjects (42.1 % female) were identified. The proportion of female subjects with chordomas was significantly higher in the pediatric cohort compared to the adult cohort (P = 0.04). Most chordomas occur in Caucasians, however African-Americans were more represented in the pediatric cohort than in the adult cohort (P = 0.01). 69.6 % (39/56) of the pediatric chordomas involved the clivus/skull base and cervical spine compared to 29.3 % (48/164) of the adult chordomas (P = 1.99 × 10⁻⁷). Only 1.8 % (1/56) of the pediatric chordomas was in the sacrococcygeal region compared to 36.0 % (59/164) of the adult chordomas (P = 2.55 × 10⁻⁸). In cases where pre-treatment imaging was available, 93.8 % (16/17) of pediatric chordomas were predominantly extra-osseous compared to 76.7 % (46/60) of adult chordomas (P = 0.17).

Conclusions

Pediatric chordomas more often affect females and occur most frequently at the craniocervical junction with decrease in incidence distally in the spine, whereas adult chordomas most frequently involve the craniocervical and sacrococcygeal regions.

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

A 63 year old male presented with a three month history of dysphagia, neck swelling and an oropharyngeal swelling on examination. Initial fine needle aspiration cytology and magnetic resonance imaging (done at a peripheral hospital) suggested a salivary gland neoplasm with lymph node metastasis. An infra-temporal approach was employed to excise the tumour mass and a modified radical neck dissection undertaken to remove the cervical metastasis. Histopathological examination with immunohistochemistry confirmed this to be a soft tissue chordoma. To the best of our knowledge, this is the first documented report of an extra-axial soft tissue chordoma presenting with synchronous metastatic disease. Though rare, this adds to the list of differential diagnoses for complex parapharyngeal lesions. A multidisciplinary approach between head and neck surgery, histopathology, radiology and sarcoma teams is paramount for arriving at the correct diagnosis and to deliver optimal treatment.

Brachyury: a diagnostic marker for the differential diagnosis of chordoma and hemangioblastoma versus neoplastic histological mimickers

Brachyury is a transcription factor which is required for posterior mesoderm formation and differentiation as well as for notochord development during embryogenesis. Due to its expression in the neoplastic cells of chordoma, a malignant tumour deriving from notochordal remnants, but not in tumors showing a similar histology, brachyury has been proposed as a diagnostic marker of this neoplasia. Though commonly considered a hallmark of chordoma, the expression of brachyury has been also documented in the stromal cells of hemangioblastoma (HBL), a slow growing tumor which may involve the central nervous system (CNS) and, rarely, the kidney. Herein we review the role of brachyury immunohistochemical detection in the identification and differential diagnosis of chordoma and HBL towards histological mimickers and suggest that brachyury is added to the panel of immunohistochemical markers for the recognition of HBL in routinary practice, principally in unusual sites.