Hodgkin lymphoma in the 2002 Wold Health Organization (WHO) classification. is divided into two major groups, one of which is subdivided:

Nodular lymphocyte predominant Hodgkin lymphoma

Classical Hodgkin lymphoma

Nodular sclerosis classical Hodgkin lymphoma

Mixed cellularity classical Hodgkin lymphoma

Lymphocyte-rich classical Hodgkin lymphoma

Lymphocyte-depleted classical Hodgkin lymphoma

NODULAR LYMPHOCYTE PREDOMINANT HODGKIN LYMPHOMA

HD,LP is often vaguely nodular. There is recent immunologic evidence indicating that the nodular form of LP Hodgkin lymphoma is of B cell origin and thus distinct from other forms of Hodgkin lymphoma.

Although relatively infrequent (<10%), lymphocyte predominant HD has a good prognosis with a 5-year survival of approximately 90%.

NODULAR SCLEROSIS CLASSICAL HODGKIN LYMPHOMA

"Lacunar" R-S variants and sclerosing bands of collagenous fibrosis forming a nodular pattern are characteristic features.

The fibrosis thickens the capsule and divides the proliferating process into "nodules" or islands.

Classic Reed-Sternberg cells are generally infrequent, but there may be numerous "lacunar" variants.

Nodular sclerosis classical Hodgkin Lymphoma is the most common type of Hodgkin lymphoma (70%).

Nodular sclerosing Hodgkin lymphoma is more common in women than other forms of Hodgkin lymphoma. Most cases (80%) have mediastinal involvement present with stage II disease.

MIXED CELLULARITY CLASSICAL HODGKIN LYMPHOMA

Mixed cellularity Hodgkin Lymphoma has numerous R-S cells in a mixed inflammatory background that obliterates the normal architecture.

Plasma cells and eosinophils are frequent. Only small amounts of fibrosis and occasional necrosis may be present.

Patients with MC Hodgkin lymphoma frequently have systemic manifestations.

Mixed cellularity Hodgkin Lymphoma is less common (20-25%) than NS,HD. Most patients are men (70%) an present with late stage (III-IV) disease and B-symptoms.

LYMPHOCYTE RICH CLASSICAL HODGKIN LYMPHOMA

Classic R-S cells are rare and difficult to find, but mononuclear "L&H" Hodgkin cells with "popcorn" shaped nuclei and inconspicuous nucleoli are present against a background of small lymphocytes. HD,LP may be diffuse (shown here) or vaguely nodular.

LYMPHOCYTE DEPLETED CLASSICAL HODGKIN LYMPHOMA

Lymphocyte-depleted classical Hodgkin lymphoma is characterized by many Reed-Sternberg cells and variants (small lymphocytes are virtually absent) or by extensive fibrosis. There are two subtypes, a sarcomatous subtype with numerous bizarre Reed-Sternberg cells and a "diffuse fibrosis" variant, with extensive fibrosis and rare Reed-Sternberg cells.

Rare (5%), this subtype is often associated with HIV infection.

Clinical features: Abdominal organs, retroperitoneal lymph nodes, and bone marrow are often involved. Peripheral lymph node involvement is less common. Approximately 70% of patients present at an advanced stage and most (80%) have B symptoms. 

In the sarcomatous variant sheets of bizarre anaplastic Reed-Sternberg-like variants are seen.

Small lymphocytes are virtually absent. You can see why many of these are now called non-Hodgkin ML, large cell anaplastic. 

In the diffuse fibrosis variant there is a disorderly diffuse fibrosis, rare lymphocytes, and often few, but easily identifiable Reed-Sternberg cells in a hypocellular background. 

The poor prognosis seen with LD,HD (<20% five year survival) may reflect the poorly differentiated state of the proliferating cells.

Reed-Sternberg cells and most Hodgkin variants express the monoclonal antigens CD15 (Leu M-1) and CD30 (Ki-l), but are CD45 (LCA-leukocyte common antigen) negative.

The exception is the Hodgkin cell of LP,HD - the "L&H" or "popcorn" cell, which is CD45 positive; CD15 negative, CD20 (L26) positive, and light-chain restricted (monoclonal). Therefore HD,LP is immunologically distinct from the other types of HD.

Despite recent advances and although there is good evidence that most if not all Hodgkin lymphomas are B-cell in origin, the etiology and pathogenesis of Hodgkin lymphoma remains largely unknown.