A rhabdoid
tumor is a rare but highly lethal
cancer which occurs mostly in
infants. It is termed
rhabdoid (literally, rod-shaped) because it presents very similarly to
rhabdomyosarcoma, another
malignancy which derives from
striated muscle. (Rhabdomyosarcoma is the most common
soft tissue tumor found in children, which occasionally leads to a delay in accurate
diagnosis). In particular, rhabdoid tumours were once thought to be a
variant of
Wilms' tumor, a common childhood form of kidney tumor. Subsequent study has disproven that theory, and rhabdoid tumours are now known to be a separate (and more malignant) form of cancer.
Diagnosis
Rhabdoid tumors may present in a variety of places, but most often affect the kidney, so that will be the case under discussion here. Rhabdoid tumor of the kidney (RTK) is a solid, highly malignant tumor which occurs exclusively in childhood, with most cases being diagnosed before the patient is a year old. Approximately three percent of children with renal tumors turn out to be afflicted with rhabdoid tumors. Boys are slightly more susceptible than girls.
Patients with RTK very often present with obvious abdominal masses -- RTK progresses frighteningly quickly, and often progresses to Stage III or IV before diagnosis. Because the children involved are so young, it is almost impossible to assess how much pain might be involved, but parents often report fussiness and crying. Hypertension (high blood pressure) is observed in as many as seventy percent of patients. Approximately half of the patients run fevers; sixty percent also show some visible amount of blood in their urine (gross hematuria). About ten percent of children who present with RTK also have rhabdoid tumors of the central nervous system. For that reason, once a firm diagnosis of RTK has been obtained, an MRI of the head should be performed.
Treatment and Prognosis
The common treatment for RTK is chemotherapy. However, this is only a matter of making the patient more comfortable in their remaining days. RTK is fatal in 100% of the cases, with only 20% of the affected patients surviving two years post-diagnosis, and none having yet been reported to survive beyond five years after RTK was diagnosed. Generally, the younger the child at the time of diagnosis, the more bleak the prognosis.
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Sources:
T Lynch, A Paterson, J Turner, P Flynn: Rhabdoid tumour
Luxembourg, Euromultimedia
URL: http://www.eurorad.org/case.cfm?UID=1598
Rhabdoid tumour of kidney,(RTK)
The Encyclopaedia of Medical Imaging, Volume VII
http://www.amershamhealth.com/medcyclopaedia/medical/volume%20VII/RHABDOID%20TUMOUR%20OF%20KIDNEY.ASP
Jeffrey S Dome, MD, D Ashley Hill, MD, Mary Elizabeth McCarville, MD: Rhabdoid Tumor of the Kidney
eMedicine.com, Inc.
http://www.emedicine.com/ped/topic3012.htm