Selected Topics on Lymphoid Lesions in the Head and Neck Regions

Abstract

Lymphoid tissue located in the head and neck region include multiple regional lymph node chains as well as mucosa associated lymphoid tissue of the conjunctiva, buccal and nasopharyngeal cavities (Waldeyer's ring), and thyroid and salivary glands. This region is a rich source of antigenic stimuli including infectious agents coming from the outside environment. Many reactive conditions that affect lymphoid tissue in this region may mimic neoplasia. In fact, distinguishing between benign and malignant lymphoid proliferations in the head and neck region is a relatively frequent diagnostic challenge and in many instances, this distinction is not straightforward. It therefore behooves the practicing pathologist to be able to recognize the benign lymphoproliferative disorders that affect this region so as to effectively guide the appropriate clinical management of such patients. Kimura disease, Epstein Barr lymphadenitis, HIV associated salivary gland disease and chronic sialadenitis are benign conditions that not infrequently affect lymphoid tissue in the head and neck region and that share certain overlapping features with malignant lymphoma. In this brief review, we discuss these conditions and highlight clinicopathological features that may help distinguish them from neoplastic lymphoproliferations that may share similar features.

Intravascular Large B-Cell Lymphoma

“…Such distortions are particularly common in Kimura disease, Epstein-Barr lymphadenitis, human immunodeficiency virus-associated salivary gland disease, and chronic sialadenitis. 32 Polymerase chain reaction testing for clonal B-and T-cell receptor genes is useful to distinguish between benign and malignant lymphoproliferation, as is careful assessment of cellular features such as degree of atypia and inclusions indicating viral infection. 32 Diagnosis and distinction of acute leukemias from IVLBCL is critical, with peripheral blood smear and analysis of degree of peripheral blood involvement being an important tool.…”

“…32 Polymerase chain reaction testing for clonal B-and T-cell receptor genes is useful to distinguish between benign and malignant lymphoproliferation, as is careful assessment of cellular features such as degree of atypia and inclusions indicating viral infection. 32 Diagnosis and distinction of acute leukemias from IVLBCL is critical, with peripheral blood smear and analysis of degree of peripheral blood involvement being an important tool. Further distinction can be made by carrying out cytogenetic analysis, because the majority of lymphoblastic tumors have nonrandom karyotypic abnormalities.…”

Imaging Evaluation of Pediatric Parotid Gland Abnormalities

“…Definition.-Owing to their origin in the mucosal lymphoid tissue, primary lymphomas of the parotid gland are classified as MALT (mucosa-associated lymphoid tissue) lymphomas (MALToma), and these account for 4.7% of lymphomas from all sites of the body (67). focal or diffuse, single or multiple, and unilateral or bilateral masses (67,68).…”

“…The pattern can be diffuse or nodular. MALT lymphomas characteristically show infiltrates of small centrocytes and monocytoid B cells with variable plasma cell differentiation, which invade parotid ductal and acinar tissue(68).…”

Human BK Polyomavirus—The Potential for Head and Neck Malignancy and Disease

“…HIV-associated non-Hodgkin lymphomas now account for most AIDS-defining cancer types, despite the overall incidence having decreased [ 113 ]. While the salivary B cell lymphoma is rather indolent and tends to remain localized, as the disease progresses, regional lymph node involvement or other extra-nodal site involvement may take place [ 114 ].…”