CASE PRESENTATION: A 74-year-old indigenous Malaysian man with underlying chronic kidney disease presented with recurrent admissions for hyponatremia with parameters indicative of syndrome of inappropriate antidiuretic hormone secretion, constitutional symptoms, and diffuse skin lesions suggestive of multiple seborrheic keratoses. A radiological workup revealed metastatic renal cell carcinoma with evidence of metastasis to the brain, adrenal glands, bone, and lungs.
CONCLUSIONS: To the best of our knowledge, renal malignancy presenting as syndrome of inappropriate antidiuretic hormone secretion and Leser-Trélat concurrently is rare. The causes of hyponatremia in the elderly, approach to investigation, and value as a poor prognostic marker in malignancy are highlighted. We also discuss Leser-Trélat syndrome, its pathophysiology, and its possible implications on clinical practice.
MATERIALS AND METHODS: Thirty-six clear cell RCC cases were selected. There were 21 (58.3%) men and 15 (41.7%) women with median age of 56.6 years (range: 16-74 years). Chinese constituted 16 (44.4%) of the cases; Malays 14 (38.9%) cases and Indian 6 (16.7%) cases. There were 6 (16.7%) grade 1, 20 (55.6%) grade 2, 10 (27.8%) grade 3 and none was grade 4. The paraffin embedded tissues were cut at 4 μm thick and stained with COX-2 monoclonal antibody.
RESULTS: Eighteen (50%) of the RCC cases were immunopositive, of which all showed strong positivity. The immunopositive cases showed cytoplasmic membrane positivity.
CONCLUSION: There was no significant association between COX-2 expression with grade, age, sex and ethnicity (p=0.457, p=0.054, p=0.389 and p=0.568 respectively). Strong positivity of COX-2 suggest that COX-2 may play a role in cell proliferation and in carcinogenesis.
MATERIALS AND METHODS: Following the preferred reporting items for systematic review and meta-analysis (PRISMA) guidelines, online searches of multiple databases were performed to retrieve articles from their inception until December 2017. Inclusion criteria included all English-based original articles of immunohistochemistry (IHC) studies investigating CAIX expression in human RCC tissue. Four articles were finally selected for meta-analysis with a total of 1964 patients. Standard meta-analysis methods were applied to evaluate the role of CAIX in RCC prognosis. The relative risk (RR) and its 95% confidence interval (CI) were recorded for the association between biomarker and prognosis, and data were analysed using MedCalc statistical software.
RESULTS: The meta-analysis showed that high CAIX expression was associated with low tumour stage (RR 0.90%, 95% CI 0.849-0.969, p= 0.004), low tumour grade (RR 0.835%, 95% CI 0.732-0.983, p= 0.028), absence of nodal involvement (RR 0.814%, 95% CI 0.712-0.931, p= 0.003) and better ECOS-PS index (RR 0.888%, 95% CI 0.818-0.969, p= 0.007). The high tissue CAIX expression in RCC is hence an indication of an early malignancy with a potential to predict favourable disease progression and outcome.
CONCLUSION: The measurement of this marker may be beneficial to determine the course of the illness. It is hoped that CAIX can be developed as a specific tissue biomarker for RCC in the near future.