Giant Cell Tumor of the Thoracic Spine in a Young Female Patient in a México City Spine Center: A Case Report

Background

Giant cell tumors of bone (GCTB) are rare osteolytic bone neoplasms with low malignant potential. They account for approximately 5% of all primary bone tumors and up to 15–20% of all benign bone tumors [1]. GCTBs are typically locally aggressive and recurrent and can evolve into pulmonary metastases. GCTBs develop after achieving skeletal maturity, affecting young adults between the ages of 20 and 40, although they can appear in older adults. Several authors have reported a slight predominance of women over men. GCTBs are associated with Paget’s disease of bone [2].

Almost all (90%) GCTBs exhibit typical epiphyseal or metaphyseal involvement. The most common locations, in decreasing order, are the distal femur, the proximal tibia, the distal radius, and the sacrum. Another uncommon site is the spinal column, where approximately 1–1.5% of GCTBs are located. Spinal GCTBs tend to enlarge, leading to compression of the adjacent nerve roots and vasculature, with variable clinical manifestations. GCTBs above the sacrum are rare [3].

Surgical resection is the universal standard of care for GCTBs, but a GCTB of the spinal column presents a unique challenge because of its anatomic location. These lesions can be expansile and lead to compression of the spinal cord. Operative intervention can incur substantial bleeding owing to the vascularity of the GCTB and require spinal reconstruction and stabilization if there is significant vertebral involvement. Moreover, the rarity of these tumors in the spine precludes the formulation of a universal algorithm for their treatment [3].

We report the clinical features, histopathology, and successful surgical treatment of a patient with a GCTB of the thoracic spine.

Case Report

A 21-year-old woman presented to the Emergency Department of the México City Health Department Spine Clinic due to an acutely worsened mid-lower back pain previously treated for 1 month with non-steroidal anti-inflammatory drugs and a muscle relaxant. Anamnesis did not reveal any relevant family history, risk factors, or exposures.

The patient reported having severe, incapacitating thoracic spine pain that worsened with activity. She could not walk by herself or be in a supine position upon arrival. The patient mentioned the presence of hypoesthesia and diminished strength.

The patient was awake, alert, oriented, and cooperative. Her cranial nerves were intact. Strength at each spinal level was evaluated according to the Daniels and Worthingham Scale. The lower extremities showed diminished strength; the right limb with 3/5 for L2 (hip flexors), L3 (knee extensors), and 4/5 for L4 (ankle dorsiflexors) and S1 (ankle plantar flexors); and the left limb with 3/5 for L2 (hip flexors), L5 (long toe extensors), and 4/5 for S1 (ankle plantar flexors). Motor strength in the upper extremities was unaltered. Hypoesthesia below the T8 level and bilateral patellar hyperreflexia (3+) were relevant clinical findings. In addition, the Babinski, Chaddock, and Gordon reflexes were positive.

A CT scan and an MRI of the spine were performed. The images revealed near destruction of the T7 vertebral body with a possible pathologic lesion and fracture associated with dorsal and ventral spinal cord compression and collapse, as well as significant signal change within the spinal cord (Figure 1).

Due to these findings, an open excision biopsy was performed employing a standard transpedicular posterior thoracic approach. The surgical team successfully conducted the procedure.

The histopathological analysis reported multiple fragments of bone trabeculae, with an erosion of the cortical bone by osteoclasts and mononuclear neoplastic cells surrounded by an eggshell border of reactive bone. The neoplastic cells showed a diffuse syncytial pattern, with a predominantly ovoid shape, eosinophilic cytoplasm, round nuclei with open chromatin, inconspicuous nucleoli, and abundant figures of mitosis; on a non-fibrotic bottom and thin-walled vessels. Therefore, a diagnosis of a GCTB was established (Figure 2).

Surgical treatment was carried out via the posterior thoracic approach, with transpedicular instrumentation of the T5–T6 and T8–T9 vertebrae under fluoroscopic control. A bilateral T7 decompressive laminectomy, lateral costotransversectomy, and posterior corpectomy were conducted to achieve a complete vertebral body and tumor resection. Finally, inter-somatic arthrodesis with an autologous tricortical iliac crest graft was performed for vertebral fusion.

The surgery was concluded without any apparent complications. Immediate post-surgical care included analgesia, initiation of early enteral nutrition, rehabilitation, and mobilization.

The patient began physical therapy 1 day after the surgery and was gradually able to sit up by herself. The Department of Spinal Cord Rehabilitation led this process, focusing on pain management, joint mobility, and muscle strengthening. Due to the rapid improvement and adequate patient evolution, she was discharged in stable conditions 2 weeks postoperatively, with prompt follow-up and daily rehabilitation. The patient was referred to an oncology center for advice and treatment continuity with Radiotherapy.

At 1-year follow-up, X-ray (Figure 3) and MRI showed good spinal alignment and no sign of tumor recurrence. The patient was painless and otherwise asymptomatic, concluding that an adequate recovery was underway. Nevertheless, the patient will be monitored periodically due to the high risk of recurrence of these lesions following surgical excision.

Discussion

In this case report, we described a 21-year-old patient with an aggravation of back pain and upper-motor neuron syndrome due to a GCTB originating from the T7 thoracic vertebra.

The most common manifestations of patients with spinal GCTBs are back pain due to an expansile lesion and neurological deficits due to vertebral collapse, leading to the compression of the spinal cord and encroachment of the neoplasm into the spinal canal [4]. Due to the involved vertebrae in this case and tumor size, if left untreated, the lesion would have possibly left the patient with severe sensory and motor deficits ending in paraplegia. Neurologic deficits usually present as upper-motor neuron syndrome, bladder and bowel dysfunction, and structural deformity of the spine [3].

The diagnostic standard for GCTBs is a biopsy. Histopathological findings show mononuclear cells interspersed with large, evenly distributed osteoclastic giant cells. Osteoclasts occasionally exceed 50% of the total cell content of the tumor [5].

There are various techniques for sample collection, with no standard of care. However, transpedicular CT-guided core-needle biopsies are the preferred and most accepted method [4].

On imaging, spinal GCTBs are round-like extrapleural masses with calcified margins and an absence of a mineralized matrix. GCTBs typically involve vertebral bodies, with or without soft-tissue invasion. An X-ray might show GCTBs, but CT and MRI provide additional information on bone and soft tissue involvement and are helpful tools for surgical planning [4].

GCTBs are radiosensitive tumors. The ideal treatment of GCTBs is complete surgical resection. Nonetheless, this approach is challenging in most cases involving the spine since many neurovascular structures are close to the neoplasm. Thus, surgeons usually perform a marginal or intralesional resection with posterior local radiotherapy. Given the complexity of spinal surgery, radiotherapy is used as an adjuvant to an excision in contrast to long-bone GCTBs, where curettage is the recommended technique. For vertebral reconstruction, cement or metallic cages are suggested [6].

Although GCTBs are classically benign, clinical courses, invasion, and recurrence rates vary widely. Complications are mostly local. The prognosis depends on the degree of medullary involvement, bone destruction, and distant metastases. GCTBs of the spine usually have a more aggressive course and worse prognosis [7].

A similar case of a GCTB in the T1–T2 intervertebral space, reported by Ramos-Trujillo et al, was treated with 2 separate surgeries and showed positive neurological results. The patient fully recovered, and sensory and motor functions were conserved [8].

There are few reports of malignant transformation, which occurs in those undergoing radiation therapy. Nonetheless, most of these are due to second primary tumors (spinal sarcomas) and not attributed to the same histopathological subtype [9,10].

Domovitov and Healey reported a 5-year recurrence-free rate of up to 91% and a 10% mortality rate [11]. A retrospective study by Boriani et al showed local recurrence in 22% of cases following surgery. In addition, ages younger than 25 years were associated with earlier recurrence [12].

Analyses by Boriani et al and Rosario et al agree that metastases occur in around 10% of patients, and local recurrence is the most important predictor for disease dissemination [12,13]. Periodic imaging during the first year and up to 5 years is effective for detecting local recurrence and distant lung metastases [13].

Conclusions

Giant cell tumors of the bone are rare entities, especially when presenting in spinal locations above the sacrum. There are few reports of GCTBs occurring in the cervicothoracic spine.

We presented a case of a GCTB in a 21-year-old, located in the seventh thoracic vertebra, a relatively rare diagnosis with a unique presentation, posing considerable challenges for medical professionals. To date, utilizing combined surgical and adjuvant therapies, the patient has had a remarkable recovery and has had no tumor recurrence.

Although rare, GCTBs should be included in differential diagnoses of spinal tumors and pathological vertebral fractures, particularly in young individuals.