ABSTRACT
BACKGROUND: According to WHO, succinate dehydrogenase (SDH)-deficient renal cell carcinoma is characterized by negative immunostaining for SDHB, which remains positive in non-tumor tissue despite germline mutations in the SDHB gene. We now report a patient with a SDHB mutation, c.166_170del (p.Pro56Tyrfs*5) who developed renal cell carcinomas with characteristic morphological features of SDH-deficient renal cell carcinoma but had positive SDHB immunostaining. CASE PRESENTATION: Within a 6-year period, the patient developed two different renal cell carcinomas, which had characteristic morphological features of SDH-deficient renal cell carcinoma (uniform cells characteristically displaying eosinophilic granular material intermixed with fewer cells exhibiting clear intracytoplasmic inclusions and bland centered nuclei) but displayed immunohistochemistry for SDHB with a cytoplasmic granular positivity (mitochondrial pattern) in tumor cells. For the second case, this was initially interpreted as positive by IHC, but on review some subtle differences were identified. CONCLUSIONS: SDHB immunostaining may be positive in renal cell carcinoma associated to germline SDHB deficiency which have other typical morphological features. Immunohistochemistry interpretation may be complex.
Subject(s)
Carcinoma, Renal Cell/genetics , Kidney Neoplasms/genetics , Succinate Dehydrogenase/genetics , Adult , Carcinoma, Renal Cell/diagnosis , Carcinoma, Renal Cell/pathology , Cytoplasm/metabolism , Germ-Line Mutation , Humans , Immunohistochemistry , Kidney Neoplasms/diagnosis , Kidney Neoplasms/pathology , Male , NephrectomyABSTRACT
BACKGROUND: The systemic consequences of esthetic filler injections are poorly understood. CASE PRESENTATION: We report a patient with a past history of subcutaneous injection of aesthetic filler material in the lower legs, who presented with post-infectious glomerulonephritis following necrotic leg ulcers at the injection site. Kidney biopsy revealed the presence of translucent, non-birefringent microspherical bodies compatible with polymethylmetacrylate (PMMA) microspheres in some capillary lumens. This had not previously been described. PMMA is a biphasic aesthetical filler composed of polymethylmetacrylate microspheres suspended in a biodegradable bovine collagen carrier. The solid phase (PMMA microspheres) persists in tissues for years. Although PMMA was thought to not disseminate systemically, tissue necrosis may have favored systemic dissemination of the microspheres, although entry in the circulation and microembolization at the time of administration cannot be ruled out. CONCLUSIONS: In conclusion, aesthetic filler implants may cause microembolization into small vessels. Recognition of the characteristic morphology may expedite diagnosis and avoid unnecessary further testing.
