In 1999, Mr T, a sports coach in his fifties, suffered transient bouts of dizziness, visual disturbance and upper limb weakness. He saw a physician who arranged an MRI scan that revealed two lesions within the right frontal lobe. The radiological diagnosis was a probable glioma.
Mr T underwent a brain biopsy to confirm the diagnosis. The biopsy specimen was examined by Dr Q, specialist neuropathologist. The request card gave the clinical information as ‘low grade astrocytoma or lymphoma’. Dr Q reported that the lesion was a grade II astrocytoma. Mr T had a course of radiotherapy. He remained well with no neurological signs.
A review MRI scan showed that the original right-sided lesion had virtually disappeared, to be replaced by multiple left-sided frontal lobe lesions. Mr T’s clinicians felt this was inconsistent with the diagnosis of glioma, so they asked Dr Q to review the histology. Dr Q performed additional staining of the specimen which suggested that the original lesion was due to demyelination rather than tumour.
The histology was subjected to an independent review which confirmed that an error had been made. The error was a well-recognised one and was due to a failure to perform adequate differential immuno-histochemical staining of the sample which would have revealed the difference between the two pathologies.
Mr T was generally well, but suffered some dysarthria and poor balance after his radiotherapy. His neurologist noted slight downward drift of his left arm when his eyes were closed but otherwise he had no neurological signs. The neurologist’s working diagnosis was multiple sclerosis.
It was clear that a breach of duty had occurred, but the question of a causal link between receiving radiotherapy and any deficit, disadvantage or injury suffered by Mr T was uncertain. He would certainly have needed a brain biopsy in any case. However, a medical error had clearly occurred and out of consideration to Mr T we decided to settle the case for a small sum.
Confusion between demyelinating and neoplastic brain disease is a recognised pitfall of this area of practice.
Two case-based papers on this potential source of confusion will be of interest to clinicians, radiologists and neuropathologists alike:
- Werneck L C et al., Glioma and Multiple Sclerosis: Case Report, Arq Neuropsiquiatr60(2-B):469–74 (2002).
- Heyman D et al., Pseudotumoral Demyelination: A Diagnosis Pitfall (Report of three Cases), J Neurooncol 54(1):71–6 (2001).
The inadequate staining of the specimen was probably due to a system error. It is worth reviewing practices and procedures regularly and monitoring performance to ensure that standards are maintained.