Histologic examination of the skin revealed classic graft versus host morphologic features consisting of a dense perivascular mononuclear cell infiltrate in the papillary and reticular dermis extending into the epidermis with vacuolar changes in the epidermal basement membrane, extensive dyskeratosis in the epidermis with severe apoptosis, and fibrin thrombi in superficial veins.
Histologic features seen in the gastrointestinal tract sections (including stomach, jejunum, ileum, appendix and colon) each showed marked perivascular mononuclear infiltrates extending throughout the lamina propria. Extensive karyorrhexis, nuclear debris and apoptotic bodies in the glandular epithelium was present.
All neck and mediastinal soft tissue was submitted for histologic examination and failed to reveal parathyroid and thymic tissue.
The bone marrow sections revealed a markedly hypocellular marrow, replace by adipose tissue. Triliniage hematopoiesis was present but in significantly depressed numbers.
Histologic sections of the spleen revealed effacement of the normal architecture with global depletion of lymphocytes and loss of germinal centers.
The architecture of the liver was distorted by massive sinusoidal congestion and centri lobular necrosis. The portal tracts contained lymphocytes with severe bile duct epithelial damage.
Renal sections revealed fibrin thrombi in the capillary loops of most glomeruli. Acute tubular necrosis was present.
Pulmonary sections revealed diffuse alveolar damage with extensive hyaline membrane formation in the alveolar air spaces.