Primary spinal conus medullaris germinoma

Summary

A woman in her early 20s presented with progressive low back pain, leg weakness and sphincter dysfunction. MRI revealed a 5 × 1.5 cm intramedullary tumour at the T12–L2 level. Elevated preoperative beta-human chorionic gonadotropin levels were noted. Surgical excision confirmed the diagnosis of a germinoma. Postoperative MRI showed no additional lesions. The patient underwent localized radiation therapy, but recurrence was noted 10 months later.

Background

Primary spinal germinomas are extremely rare intramedullary malignancies. These tumours, arising from germ cells, commonly occur in the pineal or suprasellar regions and metastasise to the spine in 10%–20% of cases. Most reported cases involve young Japanese adults with thoracolumbar spine tumours. This report describes a young female patient with primary spinal conus medullaris germinoma.^{1 2}

Case presentation

This woman in her early 20s denied any systemic diseases. She experienced low back pain after sneezing, numbness in both lower limbs and incontinence of stool and urine for several months. The symptoms progressively worsened, leading to leg weakness and frequent falls. An intramedullary tumour measuring 5 × 1.5 cm was identified within the T12–L2 region on her first lumbar spine MRI dated (figures1 2).

Figure 1. T-L spine MRI, T2, sagittal view and first lumbar spine MRI.

Figure 2. T-L spine MRI, T2, axial view and first lumbar spine MRI.

Differential diagnosis

Differential diagnoses included germ cell tumour, astrocytoma, ependymoma, haemangioblastoma, intradural metastasis and lymphoma. However, distinguishing it from primary spinal cord tumours through imaging alone is challenging.

Her preoperative beta-human chorionic gonadotropin (B-HCG) level was elevated at 23.3 mIU/mL, while other tumour markers (CEA, CA-153, CA-199 and alpha-fetoprotein) were within normal ranges. Based on these laboratory results, a germ cell tumour was highly suspected.

Treatment

One month after the diagnosis, she underwent surgical excision of the T12–L1 intramedullary tumour, measuring 5.0 × 2.0 × 2.0 cm, which was well-demarcated, hypervascularized and tightly attached to the conus medullaris (figures35).

Figure 3. Open dura and arachnoid membrane.

Figure 5. Gross total tumour excision.

Figure 4. Tumour attached to the conus.

The surgery successfully achieved gross total tumour excision. The final pathology report confirmed the presence of an intramedullary germinoma. We advised the patient to undergo chemotherapy in conjunction with localised radiotherapy. However, she declined the treatment, citing concerns regarding the potential adverse effects associated with chemotherapy. Due to personal reasons, she chose to continue treatment at another hospital, and she did not attend the scheduled follow-up appointments we arranged. Subsequently, she only received local 40 Gy of localised radiation therapy over T12–L2.

Outcome and follow-up

Four days after the surgery, follow-up brain and whole spine MRI showed no definite abnormal intracranial enhancement or signal intensity changes, and no other spinal lesions were identified. A primary spinal conus medullaris germinoma was considered. Postoperatively, B-HCG levels normalised to 2.2 mIU/mL.

A subsequent follow-up MRI of the thoracolumbar spine, performed 5 months after surgery (figure 6), showed no evidence of recurrence, and the patient’s symptoms had improved.

Figure 6. T-L spine MRI, T2, sagittal view and 5 months after surgery.

However, starting 8 months postsurgery, the patient began experiencing occasional, tolerable numbness in both lower limbs, which rapidly progressed from the groin to the toes, accompanied by severe bilateral lower-limb weakness. Despite previously being fully independent in daily activities, she became unable to walk. Occasional urinary incontinence was also noted.

A follow-up MRI of the thoracolumbar spine, performed 10 months postsurgery (figures7 8), revealed a recurrent intraspinal tumour at the T6–7 level. Subsequently, she underwent excision of the recurrent tumour at the T6–7 level, 10 months after the initial surgery. Pathology confirmed the presence of an intradural, extramedullary germinoma, indicating a recurrence.

Figure 7. L spine MRI, T2, sagittal view and 10 months after surgery.

Figure 8. T-L spine MRI, T2, axial view and 10 months after surgery.

After discussing treatment options with the patient and her family, they decided to proceed with chemotherapy (Bleomycin, Etoposide and Cisplatin) and local radiotherapy.

Discussion

The clinical symptoms and imaging features of primary spinal germ cell tumours often resemble those of other spinal cord neoplasms. A definitive diagnosis can only be established through histological examination following a surgical biopsy. The prognosis for spinal germinoma can be favourable if diagnosed and treated early, as it is highly sensitive to radiotherapy. Patients with this condition should undergo follow-up every month during the first 3 months postoperatively. Subsequently, follow-ups should be conducted every 3 months for 1 year, after which the frequency can be reduced. In cases with a high risk of recurrence—such as patients with elevated serum or CSF B-HCG levels or the presence of syncytiotrophoblastic giant cells within the tumour—combining radiotherapy with systemic chemotherapy should be considered.¹,⁶

If this patient had undergone chemotherapy in conjunction with radiotherapy immediately after the initial surgical diagnosis, the likelihood of recurrence might have been significantly reduced, potentially preventing it altogether. However, whether chemotherapy could impact the fertility of young women requires careful consideration and evaluation.

Patient’s perspective.

The initial symptoms of my condition were gradual, and at first, I thought it was just muscle soreness and didn’t pay much attention to it. However, 1 day, I suddenly found myself unable to walk. Subsequent examinations revealed that the condition was severe enough to require surgical intervention.

After the first surgery, my recovery was good. When the doctor suggested chemotherapy in addition to radiation therapy, I declined the chemotherapy due to my fear of side effects. Because another hospital was closer to home, I chose to receive my follow-up treatment. After completing radiation therapy, my leg strength was restored, and I assumed the disease was cured since follow-up MRIs showed no abnormalities.

However, the second onset of symptoms was abrupt, I experienced a sudden loss of strength. Further examinations revealed a relapse. The recovery after the second surgery was not as good as the first, and I required a walker to stand. At this point, chemotherapy was recommended again alongside radiation therapy. Despite my concerns about severe side effects and my reluctance to undergo chemotherapy, it seemed to be the only viable option given the recurrence.

I often think that if I had started chemotherapy earlier, I might have had a better outcome.

Learning points.

• Early diagnosis and treatment of spinal germinoma are crucial due to the tumour’s sensitivity to radiotherapy.

• Elevated levels of beta-human chorionic gonadotropin can assist in diagnosing germinoma.

• Gross total resection, followed by a combination of radiotherapy and systemic chemotherapy, may result in favourable outcomes. Comprehensive follow-up is essential for monitoring recurrence.