Few positive cells are present. Inflammatory reactions would show similar numbers of kappa and lambda-reactive cells. The restriction of most of the staining to the kappa-positive cells indicates clonality and hence, neoplasia. This disease is an extranodal lymphoproliferative disorder with a prominent polymorphous, reactive inflammatory component. It has been divided into two grades depending on the number of atypical cells present.
Radiographs usually show multiple nodules with or without cavitation, bilaterally.
Cutaneous and peripheral nerve manifestations may accompany it. Both, however, are considered to be non-neoplastic, reactive lymphocytes. As a result, ischemic necrosis of tumor is common. The arrows indicate the outer borders of the vessel wall. An elastic van Gieson stain is useful to find these obstructed vessels.