Preoperative MRI for oral tongue squamous cell carcinoma: timing and correlation to histopathology.

Magnetic resonance imaging (MRI) is an integral part of the evaluation of local and regional disease in tongue squamous cell carcinoma prior to surgery. The aim of this study was to evaluate the accuracy of MRI in assessing tumour dimensions, as well as the impact of the time-lag from diagnostic biopsy on the accuracy of MRI. The medical records of 64 patients with tongue carcinoma were reviewed retrospectively. Tumour maximum diameter and tumour depth of invasion were compared between pathology and MRI (T1- and T2-weighted). MRI-derived maximum tumour diameter and depth of invasion correlated strongly with histopathology: T1-weighted (r = 0.700 and r = 0.813, respectively) and T2-weighted (r = 0.734 and r = 0.834, respectively). A significant correlation was found between measurements on T1 and T2 MRI for both parameters (P = 0.955 and P = 0.984, respectively). The accuracy rate of MRI for T-staging of early tumours was low: 10% for T1 tumours; 39.3% for T2 tumours. A time-lag of less than 2 weeks between the diagnostic biopsy and MRI adversely affected the correlation of tumour dimensions. MRI is a reliable tool for evaluating tongue carcinoma; however, it overestimates early tumours. A 2-week delay after diagnostic biopsy is desired before completing an MRI. Alternatively, if logistics allow, a pre-biopsy MRI is preferred, especially for T1-T2 tumours.

Niemann Pick Disease type A in Israeli Arabs: 677delT, a common novel single mutation. Mutations in brief no. 161. Online.

A novel single base pair deletion in the acid sphingomyelinase (ASM) gene (677delT in the cDNA) was identified in 12 Israeli Arab families with Niemann-Pick disease (NPD) type A. This deletion creates a premature stop codon which explains the complete deficiency of ASM activity in these patients and the severe clinical manifestation. A single mutation in 12 families living in a relatively small geographical region suggests a founder effect and explains the high frequency of this disease in this population. This is in contrast to multiple mutations found in two other lysosomal storage disorders prevalent in this population, namely, Hurler disease (MPSI) and metachromatic leukodystrophy. Mutations analysis is therefore an important tool in characterizing the grounds for the high frequency of inherited diseases as well as a basis for prevention programs for prevalent diseases through carrier identification and the ascertainment of high risk families.