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| Year : 1999 | Volume
: 47
| Issue : 4 | Page : 314-7 |
Primary malignant rhabdoid tumours of brain, clinicoradiological findings of two cases.
Kumar R
Department of Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, U.P., 226014, India.
Correspondence Address:
Department of Neurosurgery, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, U.P., 226014, India.
Malignant rhabdoid tumours (MRT) are extremely malignant, highly aggressive and uncommon renal neoplasms of childhood with very poor prognosis. About fifteen cases of primary intracranial MRT (with their clinical details) are reported in English literature, following the recognition of this entity in 1978. Two cases of MRT are reported here. The first case, one year male baby was admitted with a very large, infiltrative, posterior fossa mass. He required elective ventilation, following the tumour decompression but ultimately died of respiratory failure during the process of weaning from the ventilator. The second child was operated for an extremely vascular, very friable, solid and lobulated tumour of temporal lobe. Radical microsurgical decompression of mass was achieved, however the child developed massive recurrence, documented five weeks after the surgery while on radiotherapy. His recurrence showed partial response to radiotherapy and chemotherapy. The child is alive at 8 month's follow up, but probably passing the terminal days of his life. Hence the recognition of this entity is very essential for the aggressive management and prognostication of the patient, which obviously seems to be different from primitive neuroectodermal tumour.
How to cite this article:
Kumar R. Primary malignant rhabdoid tumours of brain, clinicoradiological findings of two cases. Neurol India 1999;47:314 |
Malignant rhabdoid tumours (MRT) are rare neoplasms of childhood, originally regarded as rhabdomyosarcomatoid variants of Wilms' tumours.[1],[2] Though these tumours typically arise within the kidney, several cases of extrarenal origin have also been reported.[1] Analysis of twelve cases of primary intracranial MRT revealed a maximum survival of 15 months, that too in a single case (following total resection, radiotherapy and chemotherapy). Minimum survival was reported to be one week, following partial resection of tumour.[1] Most of the published papers in literature, dealing with this neoplasm, have mainly emphasized the histopathological aspect of the disease. This report presents two cases of MRT mainly dealing with their clinical and radiological features along with the aggressiveness of tumours and ultimate outcome of these cases.
Clinical Features : The records of two cases with MRT were reviewed. MRT involved one year and three years old children in the present report. Duration of symptoms was three months in both the patients. Both presented with features of raised intracranial tension. History of generalized seizures was, however, present in the second case. Examination of first case revealed, the head circumference of 49 cms, bulging of anterior fontanelle, restriction of upward gaze, left sixth nerve paresis, truncal ataxia and nystagmus while looking towards the right side. Second case had bilateral papilloedema without other focal/localizing signs. There was no palpable mass on abdominal examination in both of these cases.
Radiology : Cranial CT of first case showed a very large hyperdense, enhancing and defined mass in posterior fossa with a hypodense strip surrounding the tumour. Tumour involved almost sixty to seventy percent of posterior fossa and was infiltrating the brain stem anteriorly. Bulk of the tumour was lifting the tentorium superiorly and was extending below the foramen magnum inferiorly. Fourth ventricle could not be made out separately. There was significant obstructive hydrocephalus [Figure. 1]. Plain CT head on fifth post operative day showed significant amount of residual mass. Brain CT of the second case demonstrated bilobed, hyperdense, well enhancing left temporal mass with larger lobule occupying temporal pole and smaller involving the temporal lobe posteriorly. Medially it was compressing the mid brain with obliteration of the corresponding cistern. Temporal horn could not be delineated separately. There were smaller hypodensities in the mass [Figure. 2a]. Ultrasound of abdomen remained normal in this patient. Contrast brain CT repeated after five weeks (post operatively, while on radiotherapy; received 2400 rads.) showed a large well enhancing rounded hyperdense mass with large central irregular hypodensity and other insignificant hypodensities at operated site with significant mass effect. The mass showed sharp but irregular margins. This mass was lifting craniotomy bone outward, which was bulging out on examination too [Figure. 2b].
Surgery : Mid line suboccipital craniectomy and decompression (approximately 70% tumour removal) of tumour was done in the first case. Tumour was highly vascular, diffuse, infiltrative, suckable at places, firm at other places with it's extension all around. Cavity of fourth ventricle could not be made out separately. While dealing with brain stem invasion of tumour, the patient started episodic tachycardia and bradycardia. Surgery was stopped once heart rate reached upto thirty, which persisted for six minutes despite atropine therapy, though by this time, significant decompression of mass had been achieved. The child was conscious, followed commands and moved all the four limbs on reversal from anaesthesia.
Temporal craniotomy and radical decompression of tumour was done in second case. Tumour was extremely vascular and very friable. Though it was shrinking on coagulation, it bled with each touch of bipolar. It was a dark brown tumour resembling clumps of blood vessels; hence, operative diagnosis of choroid plexus carcinoma was considered. This child had uneventful intra operative period (other than significant blood loss) and had smooth recovery. Small necrotic cysts were present in both the cases.
Post operative Course : The first child had stormy postoperative period. He was electively ventilated for 72 hours in intensive care unit, in view of unstable intra-operative events and brain stem invasion. But on weaning off the ventilator; he developed tachypnoea and apnea after 6 hours and required ventilator again. The similar events kept on recurring at variable intervals and the child died after three weeks. The second child had a smooth post operative recovery and was given radiotherapy after two weeks. After five weeks, when this child presented with bulge of craniotomy flap without symptoms, repeat CT scan showed a large recurrence as mentioned above. Though he was put on steroid therapy but still developed recurrent episodes of raised intracranial pressure, during the course of radiotherapy and chemotherapy. Craniospinal MRI was also done to rule out other metastatic deposits, following the completion of craniospinal irradiation. He was given six cycles of chemotherapy (vincristine, etoposide and cisplatinum). Though this child is alive at 8 month's follow up, but is very sick, unable to walk, having uncontrolled headache and vomitings, even on higher doses of steroids.
Histology : The diagnosis of MRT was established by electron microscopy and immunohistochemistry in both the cases. On routine staining the tumours of both the cases showed typical rhabdoid cells having eccentric nuclei, `owls-eye' nucleoli, abundant eosinophilic cytoplasm and cytoplasmic hyaline inclusions. Immunoreactivity was demonstrated for epithelial membrane antigen, anti GFAP cytoplasmic staining and cytoplasmic inclusions. Histology of second case showed the areas of primitive neuroectodermal tumour and interspersed foci of rhabdoid cells showing eccentric nuclei, prominant nucleoli and fair amount of eosinophilic cytoplasm. Mesenchymal and epithelial components were not observed in multiple sections taken from all pieces of resected tumour [Figure. 3].
The MRT of kidney was initially described as a variant of Wilms' tumour with a particularly poor prognosis.[2] Shortly thereafter it was regarded as a distinctive neoplastic entity, separate from Wilms' tumour with characteristic histological and ultrastructural features.[3] It is recognized as an extremely malignant and aggressive renal neoplasm of infancy and early childhood; represents 1.8% of all malignant childhood kidney tumours. Primary MRT of brain is also common in infancy and early childhood with similar aggressive characteristics as documented in kidney. On analysis of eleven cases of MRT, the tumour was found to involve the children below 13 years of age. Five of 11 patients were infants and four of the children were below 6 years.[1],[4] First patient of this report was a one year male baby while the other child was 3 years male. Lethargy, ataxia, vomitings, headache, squint, seizures and irritability, remained the presenting features amongst the nine patients, other than the site specific focal signs i.e. third nerve paresis, extremity tremors. The clinical details of rest of the cases were not available, because the studies were mainly pathological. Both the cases of present report, had mainly the features of raised intracranial tension with additional history of generalized seizures in the second case.
Tumours were located in supratentorial compartment among six out of 11 patients involving mainly lobes (pineal region tumour was found in one case). Infratentorial locations involving cerebellum and brain stem were documented in 4 cases, tumour was multifocal in remaining one case.[1],[4],[5] Reasonable radiological details were not available in [eight] of eleven cases. Plain head CT of four cases showed iso to hyperdense, extensive lesions in two and mixed lesions in remaining two cases. Few calcifications were noted in two out of three documented cases. Patchy enhancement was found in two of the five cases. The enhancement was diffuse to intense in other three patients. Oedema was severe to moderate in two of three cases. Serial CT of three cases demonstrated tumour growth at primary site and new satellites at different sites in all three cases. MRI study of one case suggested the findings of solid tumour.[1] Tumour was invasive, hyperdense moderately enhancing with perifocal oedema in the first case of present paper, and bilobed, iso to hyperdense and brightly enhancing in the second case. It was present in posterior fossa of the first and temporal lobe of the second child. Small to minute areas of necroses were present in both the cases (verified on surgery). Recurrence was present at primary site in second patient. However, it was very extensive and quite early (within five weeks) having large central necrosis, which might be secondary to radiation therapy upto some extent. Total resection of tumours could be achieved in two out of ten reported cases. Partial resection/biopsy with or without radiotherapy, remained the preferable treatment amongst seven patients and no treatment was however instituted in one case, in whom the autopsy was performed. Autopsy of this case showed the extension of tumour throughout the subarachnoid space with bifrontal invasion.[1],[4]
Primary CNS rhabdoid tumours have limited histological variation than that described in renal cases. MRT contain fields of rhabdoid cells, approximately two third have the areas of classical PNET and smaller percentage have a neoplastic mesenchymal and/or epithelial component. Primary CNS rhabdoid tumours which contain PNET and mesenchymal or epithelial components in addition to classical rhabdoid areas, have been called atypical teratoid tumours.[6] MRT most consistently show immunoreactivity with antibodies against vimetin and epithelial membrane antigen, though a variety of other antigens have also been described in conjunction with these two.[7] Tumours in both the cases presented here showed typical features of MRT on histology and immunohistochemistry.
These tumours quickly disseminate through subarachnoid space and majority of patients die within 12 months of diagnosis.[8] Maximum reported survival remained 15 months in one child out of ten cases reported, who had undergone total resection, radiotherapy and chemotherapy, while one child of posterior fossa tumour died only one week after the surgery. Six cases died between 15 days to six months. One of the cases under discussion died three weeks following subtotal excision of invasive posterior fossa tumour, secondary to brain stem insult. Second patient, though alive, is not well at [eight] months' follow up.
Hence the diagnosis of primary MRT of brain can be made only pathologically. Nonspecific image findings may not be helpful in reaching the diagnosis. But the differential diagnosis may be considered in cases of large invasive childhood intracranial neoplasms.
| 1. | Hanna SL, Langston JW, Parham DM et al : Primary malignant rhabdoid tumour of brain, clinical imaging and pathological findings. AJNR 1993; 14 : 107-115.  |
| 2. | Beckwith JB, Palmer NF : Histopathology and prognosis of Wilm's tumour : results from the first national Wilms' tumour study. Cancer 1978; 141 : 1937-1948. |
| 3. | Haas JE, Palmer NF, Weinberg AG et al : Ultrastructure of malignant rhabdoid tumour of kidney. Hum Pathol 1981; 12 : 646-657. |
| 4. | Manhoff DT, Rorke LB, Yachnis AT : Primary intracranial atypical teratoid/rhabdoid tumour in a child with Canavan disease. Pediatr Neurosurg 1995; 22 : 214-222. |
| 5. | Muller M, Hubbard SL, Fukuyama K et al : Characterization of pineal region malignant rhabdoid tumours. Pediatr Neurosurg 1995; 22 : 204-209. |
| 6. | Lefkwitz IB, Rorke LB, Packer LB et al : Atypical teratoid tumour of infancy : Definition of entity. Ann Neurol 1987; 22 : 448-449. |
| 7. | Tsuneyoshi M, Daimaru Y, Hashimoto H et al : Malignant soft tissue neoplasms with histopathological features of renal rhabdoid tumours. Hum Pathol 1985; 16 : 1235-1242. |
| 8. | Satoh H, Goishi J, Sogab T et al : Primary malignant rhabdoid tumour of central nervous system : Case report and review of literature. Surg Neurol 1993; 40 : 429-434. |
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