Low Grade Lymphoma

Low-grade lymphoma of BALT

Compare the staining here with that in an adjacent section below. This one is stained for kappa light chains. Note that most of the infiltrating cells have a positive brown stain.

This section is stained for lambda light chains. Few positive cells are present. Inflammatory reactions would show similar numbers of kappa and lambda-reactive cells. The restriction of most of the staining to the kappa-positive cells indicates clonality and hence, neoplasia.

Angioimmunoproliferative Lesion/Lymphomatoid Granulomatosis

This disease is an extranodal lymphoproliferative disorder with a prominent polymorphous, reactive inflammatory component. It has been divided into two grades depending on the number of atypical cells present. Radiographs usually show multiple nodules with or without cavitation, bilaterally. Cutaneous and peripheral nerve manifestations may accompany it. The atypical cells stain with B-cell markers, show rearrangement of the heavy chain gene, and often stain with markers for E-B virus.

Angioimmunoproliferative lesion

Histologic features include:

  • A polymorphous, reactive lymphoid proliferation with PMNs and eosinophils plus scattered atypical cells with vesicular nuclei and prominent nucleoli (arrows).
  • Destructive angioinvasion (below)
  • Coagulation necrosis

AIL stained with the B-cell marker CD20

The large atypical cells stain with the B-cell marker (center). Some small lymphocytes stain with the B-cell marker, but many of them react with a T-cell marker. Both, however, are considered to be non-neoplastic, reactive lymphocytes.

Destructive angioinvasion

Destructive narrowing and occlusion of medium-sized vessels by tumor is a characteristic feature of AIL and high-grade, large cell lymphomas, as well. As a result, ischemic necrosis of tumor is common. The arrows indicate the outer borders of the vessel wall. An elastic van Gieson stain is useful to find these obstructed vessels.