Definition

For the purposes of this review, a primary head and neck lymphoma is one arising from extranodal sites, such as Waldeyer's ring, nasal cavity, paranasal sinuses, oral cavity, salivary glands, thyroid gland, larynx, and orbit. The related disorders, solitary plasma-cytoma and multiple myeloma (MM), are also included.

The myeloproliferative disorders (MPD) are a group of hematopoietic stem-cell diseases that include polycythemia rubra vera (PRV), chronic idiopathic myelofibrosis (MF), essential thrombocytosis (ET), and chronic myelogenous leukemia (CML). Each may occasionally present with head and neck manifestations and are included because of their and association with hematologic malignancies. PRV and ET are characterized by the overproduction of red blood cells and platelets, respectively. CML is often associated with extreme leukocytosis and splenomegaly. MF is characterized by marrow fibrosis resulting in marrow hypocellularity and extramedullary hematopoiesis.

Massive splenomegaly is common. All MPDs are characterized by an underlying tendency to transform into acute leukemia, greatest for CML and least for ET.

0 0

Post a comment