Clinicopathologic characterization of visceral gout of various internal organs -a study of 2 cases from a venom and toxin research center

BACKGROUND: Gout is a metabolic disorder that results in hyperuricemia and the deposition of positively birefringent monosodium urate crystals in various parts of the body. The purpose of this study was to characterize the incidence and diagnostic features of visceral gout found at necropsy in two patients. CASE PRESENTATION: The authors present an unusual report of untreated gout leading to major structure destructions in visceral organs. Gross post-mortem examination revealed a white powdery substance and display needle-like crystalline symmetry under the macroscopic on the visceral surfaces. Microscopically, the presence of crystalline deposits (urate tophi) were detected in visceral organs, such as; kidney, liver, lung and mesentery. Irrespective of its location, gout was observed, by H&E, as intracellular and extracellular eosinophilic deposits that compressed surrounding tissues. Moreover, numerous necrotizing granulomas of multifarious sizes were observed that were compounded by large aggregations of eosinophilic material (gout), surrounded by epithelioid macrophages, lymphoplasmacytic cells, foreign body multinucleated giant cells, fibrosis, fibroplasia and few edema. On the other hand, our results revealed that granulomatous nodules in the mesentery and kidney contained large numbers of gout foci compared with lung and liver. Furthermore, the immediate cause of death in these cases were not identified, but appeared to result from multiple factors, including the visceral gout due to unsuitable environmental conditions. CONCLUSION: In summary, we have identified a valid histopathologic damage index for use in laboratory studies of visceral gout. This system provides a feasible method of representing visceral damage in gout, and may allow for better understanding of the natural history, pathophysiology and the management of acute attacks of gouty visceral in this disease. Finally, to the best of our knowledge, understanding of the distribution of monosodium urate crystals within the body can aid clinical diagnosis and further understanding of the resulting pathology. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1293547351151638.