Pancreatic head melanoma producing obstructive jaundice: magnetic resonance characteristics aiding differentiation from adenocarcinoma.

A case is reported of malignant melanoma presenting as a mass in the head of the pancreas producing obstructive jaundice. On MR imaging the mass displayed signal characteristics not typical of adenocarcinoma but instead exhibited a low signal on T2-weighted images and early phase dynamic enhancement, the combination of which should suggest the possibility of melanoma.

Renal dysplasia in infants: appearance on 99mTc DMSA scintigraphy.

Infantile renal dysplasias, including multicystic dysplastic kidneys (MCDK), are reported rarely to accumulate radiopharmaceuticals on renal scintigraphy. 99mTc DMSA is a highly sensitive tracer for detecting functioning renal cortical tissue and may be more suited to studying renal dysplasia than 99mTc DTPA. We reviewed the ultrasound studies and 99mTc DMSA scintigrams of 42 infants (age range 1-12 months) with known or suspected MCDK. Overall, uptake on 99mTc DMSA scintigraphy was evident in 6/41 (15%) dysplastic kidneys. Of the 18 patients who underwent nephrectomy, histopathological examination revealed that uptake correlated closely with the presence of mature renal cortical tissue in the affected kidney. Our study shows that a small, but significant number of MCDK will show low-grade uptake on DMSA scintigraphy. This finding may be relevant given the reliance placed on renal scintigraphy in planning treatment for infants with suspected MCDK, particularly with the increasing trend for the non-operative management of this condition.