XERODERMA PIGMENTOSUM VARIANT: DNA PLOIDY ANALYSIS OF VARIOUS SKIN TUMORS AND NORMAL-APPEARING SKIN IN A PATIENT

Background. The patient with xeroderma pigmentosum provides an appropriate human model for the evaluation of tumor development and progression. Methods. We describe a patient with variant-type xeroderma pigmentosum who developed actinic keratoses, a squamous cell carcinoma, and its metastasis into a lymph node. DNA ploidy was measured and analyzed in cells of these tumors and the patient's sun-exposed as well as sun-shielded skin. Results. The sun-shielded skin showed a normal diploid dna distribution pattern, while the sun-exposed skin had an increased number of hyperdiploid cells. The actinic keratosis showed further increased hyperdiploid cells. The squamous cell carcinoma showed a large number of hyperdiploid cells and formed an aneuploid cell fraction. Histographically, the aneuploid cell fraction became more apparent and was revealed to be a major fraction in the metastatic squamous cell carcinoma. Conclusions. The changes in the DNA ploidy pattern well reflect the clinical and histologic characteristics of the respective skin conditions and likely provide the cellular basis for the sequential or stepwise carcinogenic process in the patient's xeroderma pigmentosum skin. Further studies are necessary to determine whether the present results explain the similar carcinogenic process in sun-damaged skin of the nonpredisposed general population.     

Comparison of Outcomes of Lumbar Interbody Fusion and Full-endoscopic Laminectomy for L5 Radiculopathy Caused by Lumbar Foraminal Stenosis

This study compared the outcomes of microendoscopy-assisted lumbar interbody fusion (ME-LIF) and uniportal full-endoscopic laminectomy (FEL) for L5 radiculopathy caused by lumbar foraminal stenosis (LFS). ME-LIF was performed using an 18- to 20-mm tubular retractor and endoscope, and FEL via the translaminar approach (TLA) was performed at the dorsal part of the foramen using a 4.1-mm working channel endoscope. Patients with LFS treated using ME-LIF (n = 39) or FEL-TLA (n = 30) were retrospectively evaluated. Patients'' background and operative data were collected. The 36-item Short Form Survey (SF-36), Oswestry Disability Index (ODI), and European Quality of Life-5 Dimension (EQ-5D) scores were recorded preoperatively and 2 years postoperatively. The background data of the two groups (ME-LIF and FEL-TLA) were similar. The mean operation times for ME-LIF and FEL-TLA were 110.7 and 65.2 min, respectively, and the mean length of hospital stay were 10.3 and 1.5 days, respectively. Reoperation was required for surgical site infection, and percutaneous pedicle screw malposition in three patients was treated using ME-LIF. During follow-up, second FEL-TLA and LIF were performed for recurrent L5 radiculopathy in one and three patients in the FEL-TLA group, respectively. Although the SF-36, ODI, and EQ-5D scores 2 years postoperatively improved in both groups, improvement in ODI scores was lower following FEL-TLA than following ME-LIF. FEL-TLA can be performed to treat patients with L5 radiculopathy caused by LFS. Although the ODI score improvement following FEL-TLA was unremarkable, FEL-TLA might be considered because of its better safety profile and minimal invasiveness than ME-LIF.