Angiomatosis with luminal cryoprotein deposition.

Background: Angioendotheliomatosis has recently been separated into two types. Malignant angioendotheliomatosis is a lymphoma in which the neoplastic cells accumulate in vascular lumens. Reactive angioendotheliomatosis is a proliferation of capillaries that is less well characterized.
Objective: Our purpose was to describe the clinical and histopathologic features of three cases of reactive angiomatosis in patients with cryoproteinemia.
Methods: Clinical and histologic data were correlated. Immunoperoxidase staining and electron microscopy were used in the histologic evaluation.
Results: All three cases showed tufts of capillaries with luminal deposits of cryoproteins. Immunohistochemical studies showed that the cellularity of the tufts was primarily caused by a proliferation of pericytes.
Conclusion: Cryoproteinemia can cause angiomatosis that simulates a vascular neoplasm.