Multiphoton Microscopic Study of the Renal Cell Carcinoma Pseudocapsule: Implications for Tumour Enucleation.

OBJECTIVE: To utilize Multiphoton Microscopy (MPM) as a novel imaging technique to characterize and quantify collagen at the Renal Cell Carcinoma Pseudocapsule, to assess for both intra-tumoral and inter-tumoral variation of collagen characteristics. MPM combines Second Harmonic Generation and Two Photon Excitation Fluorescence to image extracellular matrix architecture. METHODS: Twenty partial nephrectomy specimen tissues were retrieved, cut into 5-micron sections, mounted on slides and deparaffinized. The pseudocapsules (PCs) were imaged with 2X and 20X objective at selected Regions of Interest. Corresponding clinical information was retrieved. PC thickness was determined. Collagen parameters measured included quantification by the Collagen Area Ratio, and qualitative measurements by the Collagen Fiber Density and Collagen Reticulation Index. RESULTS: The boundaries between tumor, PC and normal renal parenchyma were distinguished by MPM without need for staining. In the thickest areas of the PC, collagen content and density were quantitatively higher compared to the thinnest areas. Median Collagen Area Ratio was higher in the thickest compared to the thinnest areas of the PC (P = .01). Clear Cell RCC specimens had a consistently higher Collagen Fiber Density in both the thickest and thinnest areas compared to non-Clear Cell RCC specimens (P = .02). CONCLUSIONS: We demonstrated the ability of MPM to quantify collagen characteristics of PCs without fluorescent labeling. Tumor enucleation for Renal Cell Carcinoma along its PC remains debatable with regards to oncological safety. Even with a complete and intact PC, the PC is not a homogenous structure, and varies in its thickness and its collagen characteristics within, and between tumors.

The pediatric fracture of the scaphoid in patients aged 13 years and under: an epidemiological study.

BACKGROUND: Fractures of the scaphoid are uncommon in the pediatric population. Despite their rarity, a significant number of children are referred to the fracture clinic for a suspected scaphoid fracture. The aim of this study was to report on the current incidence, pattern of injury, and the long-term outcomes following this injury in the pediatric population. METHODS: Analysis of all pediatric scaphoid fractures presenting to a tertiary pediatric hospital (aged 13 y and under) over a 5-year period was performed. The case notes, radiographs, and other imaging studies for these patients were reviewed. Long-term functional outcome was assessed using Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire. RESULTS: Fifty-six patients of the 838 (6.7%) referred for a suspected scaphoid fracture were identified as having a confirmed diagnosis of a scaphoid fracture, giving an average annual incidence of 11 per 100,000. This group consisted of 39 boys (70%) and 17 girls (30%). The average age of incidence in boys was 12.2 years and in girls was 10.3 years (P<0.001). No scaphoid fractures were observed in boys below the age of 11 years and in girls below the age of 9 years. The most common type of fracture was a distal pole fracture (45 patients). One patient sustained a proximal pole fracture and went on to develop a nonunion. The duration of treatment in cast was shorter in distal pole fractures than in other types (P<0.001). At a mean follow-up of 70 months (range, 46 to 104 mo), 60% reported no limitation or impact when reporting a range of daily functional activities (mean DASH score=3.0). CONCLUSIONS: There is a suggestion that the overall incidence of scaphoid fractures in the pediatric population is increasing, but children aged 13 years and under continue to maintain a distinct fracture pattern when compared with adolescents and adults. The majority involves the distal third of the scaphoid and carries a good prognosis with conservative management. LEVEL OF EVIDENCE: Prognostic study, Level 4.