Hodgkin lymphoma

Hodgkin's lymphoma, formerly known as Hodgkin's disease, is a type of lymphoma described by Thomas Hodgkin in 1832, and characterized by the presence of Reed-Sternberg cells. more...

Epidemiology

Unlike other lymphomas, whose incidence increases with age, Hodgkin's lymphoma has a bimodal incidence curve: that is, it occurs more frequently in two separate age groups, the first being young adulthood (age 15-35), the second being in those over 50 years old. Overall, it is more common in males, except for the nodular sclerosis variant (see below) of Hodgkin disease, which is more common in women.

The incidence of Hodgkin's disease is about 4/100,000 people/year, and accounts for a bit less than 1% of all cancers worldwide.

Symptoms

Swollen, but non-painful, lymph nodes are the most common sign of Hodgkin's lymphoma, often occurring in the neck. The lymph nodes of the chest are often affected and these may be noticed on a chest X-ray.

Splenomegaly, or enlargement of the spleen, occurs in about 30% of people with Hodgkin's lymphoma. The enlargement, however, is seldom massive. The liver may also be enlarged due to liver involvment in the disease in about 5% of cases.

About one-third of people with Hodgkin's disease may also notice some systemic symptoms, such as low-grade fever, night sweats, weight loss, itchy skin (pruritis), or fatigue. Systemic symptoms such as fever and weight loss are known as B symptoms.

Diagnosis

Hodgkin's lymphoma must be distinguished from non-cancerous causes of lymph node swelling (such as various infections) and from other types of cancer. Definitive diagnosis is by lymph node biopsy (removal of a lymph node for pathological examination). Blood tests are also performed to assess function of major organs, to detect lymphoma deposits or to assess safety for chemotherapy. Positron emission tomography is used to detect small deposits that do not show on CT scanning.

Pathology

Macroscopy

Affected lymph nodes (most often, laterocervical lymph nodes) are enlarged, but their shape is preserved because the capsule is not invaded. Usually, the cut surface is white-grey and uniform; in some histological subtypes (e.g. nodular sclerosis) may appear a nodular aspect.

Microscopy

Microscopic examination of the lymph node biopsy reveals complete or partial effacement of the lymph node architecture by scattered large malignant cells known as Reed-Sternberg cells (typical and variants) admixed within a reactive cell infiltrate composed of variable proportions of lymphocytes, histiocytes, eosinophils, and plasma cells. The Reed-Sternberg cells are identified as large often binucleated cells with prominent nucleoli and an unusual CD45-, CD30+, CD15+/- immunophenotype. In approximately 50% of cases, the Reed-Sternberg cells are infected by the Epstein-Barr virus.

Read more at Wikipedia.org