Hodgkin Lymphoma Overview

Definition and Etiology

• Hodgkin lymphoma, also known as Hodgkin's disease, is a type of cancer of the lymphatic system.
• Epstein-Barr virus infection may play a significant role in the development of some subtypes, especially in pediatric patients from tropical or developing countries.

Epidemiology

• There are three peaks of incidence: childhood (0-14 years), young adult (15-34 years), and older adult Hodgkin's disease (55+ years).

Clinical Features

• Localized painless lymphadenopathy
• Fever, night sweats, and weight loss are more common in CHL than NLPHL

Types of Hodgkin Lymphoma

• Nodular sclerosing
• Mixed cellularity
• Lymphocyte depleted
• Lymphocyte rich
• Nodular lymphocyte predominant

Histologic Description

• Classic Hodgkin Lymphoma:
  • Neoplastic cells are Hodgkin and Reed-Sternberg (HRS) cells which usually express CD15 and CD30
  • Effaced lymph node with variable number of HRS cells in a background of inflammatory cells
• Types of Reed-Sternberg cells:
  • Classic HRS cells: large, binucleate or bilobed nucleus, may have single/multiple multilobate nucleoli or large, inclusion-like, owl-eyed eosinophilic nucleoli
  • Mononuclear RS variant: single round or oblong nucleus with large inclusion-like nucleoli
  • "Mummified" cells: HRS cells with condensed cytoplasm and pyknotic reddish nuclei
  • "Lacunar" cells: HRS cells surrounded by formalin retraction artifact, characteristic for nodular sclerosing subtype
  • Popcorn cells: found in nodular lymphocyte predominant subtype

Subtypes of Hodgkin Lymphoma

• Nodular sclerosis:
  • Nodular growth pattern with broad fibroblast-poor birefringent collagen bands surrounding at least one nodule
  • Highly variable numbers of HRS cells, small lymphocytes, and other inflammatory cells
• Mixed cellularity:
  • Effaced lymph node architecture; interfollicular pattern also possible
  • May have interstitial fibrosis but no broad bands of sclerosis or capsular thickening
  • Typical HRS cells in a variable inflammatory background
• Nodular lymphocyte predominant:
  • Total replacement of nodal architecture by expansive vague nodules of small lymphocytes -Sparse, relatively large tumor cells with multilobulated or round nucleus, thin nuclear membrane, finely granular chromatin, and variable small nucleoli (popcorn cells)

Staging

• Stage I: A single lymph node area or single extranodal site
• Stage II: 2 or more lymph node areas on the same side of the diaphragm
• Stage III: Lymph node areas on both sides of the diaphragm
• Stage IV: Disseminated or multiple involvement of the extranodal organs