Renal intratubular casts Intratubular hemoglobin casts Intratubular haemoglobin casts A type of acelluar intratubular casts that have a surface composed of granules, which can vary in size. The granules can be rather heterogeneous, ranging from fine (finely granular cast) up to coarse (coarsely granular cast), dark, clear, and pigmented. On H&E (red granular), PAS (purple), trichrome (red granular), Hall (yellow brown). Stain positively for Hemoglobin A.