Management of non-visualization following dynamic sentinel lymph node biopsy for squamous cell carcinoma of the penis

Objectives: To review the management and clinical outcomes of uni- or bilateral non-visualization of inguinal lymph nodes during dynamic sentinel lymph node biopsy (DSNB) in patients diagnosed with penile cancer and clinically impalpable inguinal lymph nodes (cN0), and to develop an algorithm for the management of patients in which non-visualization occurs. Patients and Methods: This is a retrospective observational study over a period of 4 years, comprising 166 patients with penile squamous cell carcinoma undergoing DSNB and followed up for a minimum of 6 months. All cases diagnosed with uni- or bilateral non-visualization of sentinel nodes in this cohort were identified from a penile cancer database. The management of the inguinal lymph nodes after non-visualization and the oncological outcomes including local and regional recurrence rates were documented. Results: Out of 166 consecutive patients undergoing DSNB, 20 patients (12%) had unilateral non-visualization after injection of intradermal 99mTc. Of these 20 patients, seven underwent repeat DSNB at a later date, with six having successful visualization. One patient had persistent non-visualization and proceeded to a superficial modified inguinal lymphadenectomy (SML). None of these patients experienced recurrence at follow-up. A further seven patients underwent modified SML with on-table frozen-section analysis of the lymph node packet; none of these patients were found to have micrometastatic disease in the inguinal lymph nodes, although one patient developed metastatic inguinal node disease at a later date. Six patients elected to undergo clinical surveillance and have remained disease-free. Conclusion: Patients with impalpable inguinal lymph nodes undergoing DSNB with ≥G2 T1 disease should ideally have bilateral visualization of the sentinel lymph nodes, reflecting the drainage pattern from the primary tumour. In the present series, 12% of patients were found to have unilateral non-visualization after DSNB. Among patients offered a repeat DSNB at a later date, localizing the sentinel node was successful in 86% of cases. Patients with favourable histological characteristics can be placed on clinical surveillance. Those with high-risk disease can be offered a repeat DSNB procedure on the proviso that SML may be carried out if there is repeated non-visualization. Larger cohorts are required to validate this proposed algorithm

Necrotizing granulomatous inflammation of the glans penis

We describe the case of a 73-year-old man who presented with a 10-month history of an ulcerating lesion on the glans penis. Initially this was thought to be an invasive squamous cell carcinoma but a biopsy showed histological features consistent with necrotizing granulomatous inflammation. Extensive serological, immunological and microbiological tests only showed a positive antinuclear and perinuclear antineutrophil cytoplasmic antibodies indicating a possible autoimmune aetiology but an underlying systemic cause was not identified. Treatment with oral corticosteroids limited the inflammatory process but due to the gross destruction of the glans penis, he still required a glansectomy and split-skin graft reconstruction from which he recovered well. Although this patient ultimately required surgery for this rare presentation, this case highlights the differential diagnosis of penile ulceration (that transcends neoplasia) and the importance of performing and interpreting penile biopsies before undertaking potentially mutilating definitive surgery

The association of abdominal muscle with outcomes after scheduled abdominal aortic aneurysm repair

Sarcopenia is the degenerative loss of core muscle mass. It is an aspect of frailty, which is associated with increased rates of peri‐operative harm. We assessed the association of the cross‐sectional areas of abdominal muscles, including psoas, with survival during a median (IQR [range]) follow‐up of 3.8 (3.2–4.4 [0.0–5.1]) years after scheduled endovascular (132) or open (5) abdominal aortic aneurysm repair in 137 patients. In multivariate analysis, mortality hazard (95%CI) was independently associated with: age, 1.06 (1.01–1.13) per year, p = 0.03; and the adjusted area of the left psoas muscle, 0.94 (0.81–1.01) per mm2.kg−0.83, p = 0.08. Shortened hospital stay was independently associated with haemoglobin concentration and adjusted left psoas muscle area, hazard ratio (95%) 1.01 (1.00–1.02) per g.l−1 and 1.05 (1.02–1.07) per mm2.kg−0.83, p = 0.04 and 0.001, respectively

A Screen for Spore Wall Permeability Mutants Identifies a Secreted Protease Required for Proper Spore Wall Assembly

The ascospores of Saccharomyces cerevisiae are surrounded by a complex wall that protects the spores from environmental stresses. The outermost layer of the spore wall is composed of a polymer that contains the cross-linked amino acid dityrosine. This dityrosine layer is important for stress resistance of the spore. This work reports that the dityrosine layer acts as a barrier blocking the diffusion of soluble proteins out of the spore wall into the cytoplasm of the ascus. Diffusion of a fluorescent protein out of the spore wall was used as an assay to screen for mutants affecting spore wall permeability. One of the genes identified in this screen, OSW3 (RRT12/YCR045c), encodes a subtilisin-family protease localized to the spore wall. Mutation of the active site serine of Osw3 results in spores with permeable walls, indicating that the catalytic activity of Osw3 is necessary for proper construction of the dityrosine layer. These results indicate that dityrosine promotes stress resistance by acting as a protective shell around the spore. OSW3 and other OSW genes identified in this screen are strong candidates to encode enzymes involved in assembly of this protective dityrosine coat

Cryptococcus gattii Virulence Composite: Candidate Genes Revealed by Microarray Analysis of High and Less Virulent Vancouver Island Outbreak Strains

Human and animal cryptococcosis due to an unusual molecular type of Cryptococcus gattii (VGII) emerged recently on Vancouver Island, Canada. Unlike C. neoformans, C. gattii causes disease mainly in immunocompetent hosts, despite producing a similar suite of virulence determinants. To investigate a potential relationship between the regulation of expression of a virulence gene composite and virulence, we took advantage of two subtypes of VGII (a and b), one highly virulent (R265) and one less virulent (R272), that were identified from the Vancouver outbreak. By expression microarray analysis, 202 genes showed at least a 2-fold difference in expression with 108 being up- and 94 being down-regulated in strain R265 compared with strain R272. Specifically, expression levels of genes encoding putative virulence factors (e.g. LAC1, LAC2, CAS3 and MPK1) and genes encoding proteins involved in cell wall assembly, carbohydrate and lipid metabolism were increased in strain R265, whereas genes involved in the regulation of mitosis and ergosterol biosynthesis were suppressed. In vitro phenotypic studies and transcription analysis confirmed the microarray results. Gene disruption of LAC1 and MPK1 revealed defects in melanin synthesis and cell wall integrity, respectively, where CAS3 was not essential for capsule production. Moreover, MPK1 also controls melanin and capsule production and causes a severe attenuation of the virulence in a murine inhalational model. Overall, this study provides the basis for further genetic studies to characterize the differences in the virulence composite of strains with minor evolutionary divergences in gene expression in the primary pathogen C. gattii, that have led to a major invasive fungal infection outbreak