Macroscopically the grains are yellow or white. They are difficult to distinguish from the surrounding fat. Histologically the large grains have a characteristic variegated pattern. The periphery of the grain is dense, homogenous and deep purple while the centre is less dense or even appears hollow. Not infrequently the grain fragments into geometric fragments. The periphery shows a brightly eosinophilic material forming clubs. This, material contains immunoglobulins. Smaller grains are more homogeneous and are difficult to distinguish from A. pelletierii.
However, even the small grains of A. madurae have a more deeply stained purple fringe, which is not seen in A. pelletierii. The inflammatory reaction is similar to that of A. pelletierii.