Micrograph showing a classic<unk>  Micrograph showing a "popcorn cell", the<unk>  variant seen in nodular lymphocyte predominant Hodgkin lymphoma.H&E stain<unk> s (also known as lacunar histiocytes for certain types) are distinctive, giant cells found with light microscopy in biopsies from individuals with Hodgkin lymphoma. They are usually derived from B lymphocytes, classically considered crippled germinal center B cells. In the vast majority of cases, the immunoglobulin genes of<unk> s have undergone both V(D)J recombination and somatic hypermutation, establishing an origin from a germinal center or postgerminal center B cell. Despite having the genetic signature of a B cell, the<unk> s of classical Hodgkin lymphoma fail to express most B-cell–specific genes, including the immunoglobulin genes. The cause of this wholesale reprogramming of gene expression has yet to be fully explained. It presumably is the result of widespread epigenetic changes of uncertain etiology, but is partly a consequence of so-called “crippling” mutations acquired during somatic hypermutation. Seen against a sea of B cells, they give the tissue a moth-eaten appearance.<unk> s are large (30–50 microns) and are either multinucleated or have a bilobed nucleus with prominent eosinophilic inclusion-like nucleoli (thus resembling an "owl's eye" appearance).<unk> s are CD30 and CD15 positive, usually negative for CD20 and CD45. The presence of these cells is necessary in the diagnosis of Hodgkin lymphoma<unk>  the absence of<unk> s has very high negative predictive value. The presence of these cells is confirmed mainly by use of biomarkers in immunohistochemistry. They can also be found in reactive lymphadenopathy (such as infectious mononucleosis immunoblasts which are RS like in appearance, carbamazepine associated lymphadenopathy) and very rarely in other types of non-Hodgkin lymphomas. Anaplastic large cell lymphoma may show RS-like cells as well.
Reed–Sternberg cell
Touton giant cell
Small cleaved cells
Langhans giant cell
Howell–Jolly body
Lutzner cells
Hematoxylin body
Acanthocyte