Archive for the ‘Rare Cancer Presentations’ Category

Rare Cancer Presentations: Intraspinal Metastasis of Lung Cancer

January 7, 2009

Author: Barry C. Mirtsching, MD  (Center for Oncology Research & Treatment, PA, Dallas, TX)

Spinal column metastasis of solid tumors are not uncommon.  Most of these tumors are extrdural in location.  However, intradural metastases are rare, comprising only  6% of all spinal metastases, involving the subarachnoid space, filum terminale, or spinal cord.  Reports of such cases in the English literature are rare.  This report reviews a case of a patient with non-small cell lung cancer (NSCLC)  who progressed with disease involving the filum terminale.  A similar case was reported previously (Su, J-H et al., Tzu Chi Med J; 2005. 17: 421-423.)

Case Description:

A 62 year old white male smoker presented in 6/2007 with cough and was found to have a 4 cm right upper lobe (RUL) tumor, with associated ipsilateral mediastinal lymph node enlargement and right supraclavicular lymphadenopathy.  A biopsy of the RUL tumor revealed bronchogenic adenocarcinoma.  He was treated with weekly carboplatin +paclitaxel, and concurrent radiotherapy to the involved regions.  He then had 4 cycles of full-dose carboplatin and paclitaxel chemotherapy.  He had partial respone in his disease by CT scans, but his supraclavicular nodal disease progressed within three months of completion of therapy.  He was then treated with pemetrexed for 4 cycles, but his disease continued to progress in the right supraclavicular area.  The patient was then treated on an investigational protocol of sunitinib and erlotinib for two months, with further progression of his supraclavicular nodal disease.  He developed severe pain in the lumbar area, with radiation to his bilateral lower extremities.  He did not have bowel or bladder disturbance.  He had mild hypoaesthesia in his pelvis and lower extremities, and subjective weakness.  The patient was moderately debilitated (ECOG performance status 2) and was losing weight.  At this time, the patient came to our Center  for evaluation and further care in 7/2008.

Evaluation of his CT scans revealed scar-like density in the RUL and ipsilateral mediastinum and a 2 cm nodule in the left lower lobe.  MRI of the spine revealed a mass in the lumbar area below the terminus of the cord, involving the filum terminale.  The mass extended in the spinal sac from T2 to T4, without extension into the extradural tissue.  The mass was enhancing on T1 imaging with gadolinium (Figure 1, T1 with gadolinium sagital images), and it was easily recognized on T2 images (Figure 2, T2 sagital images).   The patient was also found to have a 1 cm right cerebellar metastasis.

Figure 1:

MRI images T1 with gadolinium
MRI images T1 with gadolinium
Figure 2:
MRI image T2

MRI image T2

 The patient obtained pain control with narcotic therapy and radiotherapy to the spinal lesion.  His cerebellar metastasis was treated with stereotactic radiosurgery and whole brain radiation.  These areas were symptomatically completely controlled (sensory function normalized, no appearance of objective motor weakness) and did not progress for 5 months following completion of treatment.

The patient continued with systemic therapy for his cancer, with stable disease in the supraclavicular region and left lung for 5  months.  He sequentially received single-agent docetaxel and single-agent gemcitabine.  His disease in the supraclavicular area and lung progressed, and he declined further therapy.

Discussion:

This case illustrates the MRI appearance of an usual intraspinal metastasis of lung cancer involving the filum terminale.   Symptoms of pain, hypoaesthesia below the level of the lesion, lower extremity weakness, and bowel or bladder contractile disturbance may be associated with such disease.  Treatment with surgical decompresion could be considered for relief of acute neurologic compromise, such as paralysis.  However, in this case the lesion was treated with radiotherapy, because of the patient’s poor performance status, progressive systemic disease at other sites requiring chemotherapy, absence of significant motor impairment, and  poor predicted short-term prognosis.   Radiotherapy was effective for prevention of progressive neural impairment and for pain relief.