CRP-44
CRP-44
Clinical History
History of polymyositis, hypercalcemia and proteinuria. Negative serology.
Gross Description
Received in transport medium are two cores that measure 12 and 18 mm in length and 2 mm in diameter. A 5-mm fragment is taken for immunofluorescence, four 1-mm pieces are taken for EM, and the remaining tissue is submitted for light microscopy.
Pathology
Case CRP-044 H&E
Case CRP-044 PASH
Microscopic Description
Light Microscopy
The specimen consists of two fragments of renal cortex that contain eight-six glomeruli in the three levels. Fourteen of these are obsolete, but the rest show minimal mesangial expansion and no proliferation. The capillary basement membranes are unremarkable with the silver stain. The PASH and trichrome stains show diffuse mild interstitial fibrosis and focal tubular atrophy. There are numerous lymphoid aggregates throughout the cortex, and there are also numerous noncaseating granulomata. Special stains for acid fast bacilli and fungi are negative with adequate controls. Occasional examples of mild tubulitis are identified. There is mild hyaline arteriosclerosis. The larger vessels are unremarkable.
Immunofluorescence
There are five glomeruli in the sections. There is 1+ segmental mesangial staining for IgM, IgA, C3 and lambda. There is no glomerular staining for IgG, Clq, albumin or kappa. There is no staining of the tubular basement membranes or vessels.
Electron Microscopy
Three thick sections are available, but there is only one glomerulus, which is unremarkable by light microscopy. Ultrastructural examination reveals no significant increase in mesangial matrix, and no mesangial deposits are identified. The glomerular basement membranes show focal mild thickening and wrinkling, and there is also focal fusion of the foot processes. No deposits are noted along the capillary loops.