Marek’s disease – microscopy image

Marek’s disease is a lymphoproliferative avian illness similar to avian leukosis. Above, on the left, note how the neoplastic infiltration resulted in the destruction of several hepatocytes (H&E, 100x). In greater magnification (on the right), it can be clearly seen that the neoplastic cells comprise a mixed population of mature lymphocytes and lymphoblasts (H&E, 400x). Below, note the peripheral nerve infiltration by lymphoid neoplastic cells (which is not found in avian leukosis) (H&E, 100x).