Year : 2003 | Volume
: 13 | Issue : 4 | Page : 443--445
JD Meenal, R Ravi
Department of Radiodiagnosis, K.A.P. Viswanathan Government Medical College, Trichirappalli-620 017, Tamil Nadu, India
J D Meenal
Bharani Flats, 19-A, Renganatha Puram, Officers Colony, Puthur, Trichirappalli-620 017, Tamil Nadu
|How to cite this article:|
Meenal J D, Ravi R. Mesoblastic nephroma.Indian J Radiol Imaging 2003;13:443-445
|How to cite this URL:|
Meenal J D, Ravi R. Mesoblastic nephroma. Indian J Radiol Imaging [serial online] 2003 [cited 2020 Sep 28 ];13:443-445
Available from: http://www.ijri.org/text.asp?2003/13/4/443/28731
Mesoblastic nephroma (MN) is a rare renal developmental tumour detected antenatally or during the first year of life. We wish to report a case diagnosed antenatally.
A 25-year-old primigravida was referred for antenatal ultrasound. The scan survey revealed a live fetus of 32 weeks gestation in cephalic presentation. Abdominal survey of the fetus showed normal gastric bubble [Figure 1] and a 5.6 x 4x 3.4 cm. solid homogenous hypoechoic mass in the right renal fossa [Figure 2] & [Figure 3]. The left kidney was seen normally. There was associated polyhydramnios (AFI = 22). An antenatal diagnosis of mesoblastic nephroma was made.
The fetus had bradycardia.(48 /bpm). Subsequently the mother delivered a still born child [Figure 4]. Postnatal ultrasound study of the baby confirmed the right renal mass [Figure 5] & [Figure 6].
Autopsy and HPE confirmed the lesion as mesoblastic nephroma [Figure 7].
Nearly all solid renal tumours diagnosed antenatally and in the first few months of postnatal life are MN and not Wilm's. MN constitutes 3% of all neoplasms in children. Mean age is 2 months. 62% present before 3 months and 90% present in the first year of life.
It was first described by Bolande in 1967 in a 6 month old infant. Eventhough it is referred as renal hamartoma this tumour is benign and is composed primarily of mesenehymal connective tissue which produces concentric echogenic and hypoechoic ring resembling uterine fibroid in USG. These are unilateral, unicentric mass arising within the deep parenchyma near renal sinus. It may in course of time form heterogenous mass with haemorrhage and cyst formation, secondary to central region of necrosis or due to progressive accumulation of ground substance in a loose myxoid tissue of spindle and stellate cells.
About 14% of cases are associated with prematurity and polyhydramnios . The mechanism behind increased amniotic fluid is not known. But polyhydramnios generally result in preterm labour. Post natally it can present with hypercalcemia and hyper renninism. Hypercalcemia is due to prostaglandin E secreted by tumour cells. Hyperrenninism is due to rennin secretion by entrapped glomeruli.
Two morphological subtypes described histologically are classical leiomyomatous type and atypical cellular type. the classical type shows 'ring sign' in USG ie., an l,lanechoic ring surrounding the tumour which shows Doppler signal. Atypical cellular type has an agressive behaviour.
Cytogenetically 2 cell lines were found. 1. Normal 46 X Y karyotype. 2. Hyperdiploid 51 X Y karyotype including rearrangement of ch 11 at P 15. ETV6-NTR k3 gene found in both classical mesoblastic nephroma and infantile fibrosarcoma suggests that both have a common pathogenetic pathway and can occur synchronously in the same organ. Nephrectomy is curative in classical type. Wilm's tumour, multicystic dysplastic kidney, nephroblastomatosis and neuroblastoma are to be considered as differential diagnosis.
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