Definition
An angiocentric, angiodestructive lymphoproliferative disease of extranodal sites composed of EBV-positive B-cells and reactive T-cells5,7.
Angiocentric immunoproliferative lesion.
This is a rare condition, usually presenting in adults9, but also seen in children with immunodeficiency. The male to female ratio is 2:16,9. Predisposing factors include immunodeficiency from various causes; AIDS4,5, allogeneic organ transplantation5, Wiskott-Aldrich syndrome5, and X-linked lymphoproliferative syndrome, treatment for leukaemia or lymphoma, and agnogenic myeloid metaplasia. In idiopathic cases, impairment of various immune parameters has been reported: immunoglobulin concentrations are often abnormal9. There is a case report of LYG after treatment of a GIST with imatinib.
Most commonly involves the lung, with most patients developing pulmonary involvement at some stage. Other common sites are skin (25-50%)1,5, kidney (32%)5, liver (29%)5, brain (26%)5, upper respiratory tract and gastrointestinal tract. Lymph nodes and spleen are rarely involved. Most patients present with respiratory tract signs6,9, fever9, rash9, malaise, weight loss, arthralgias, myalgias and GI symptoms. The upper respiratory tract may show ulcero-destructive lesions.
The pulmonary involvement results in nodules9 of varying size within the mid and lower zones, often of "cannon ball" appearance. Large nodules become centrally necrotic and cavitate.
There is an angiocentric angiodestructive polymorphous lymphoid infiltrate. This is composed of lymphocytes admixed with plasma cells, immunoblasts and histiocytes10. Neutrophils and eosinophils are inconspicuous and well-formed granulomata are absent. The lymphocytes are mainly T-cells, which are negative for EBV3. The EBV-positive B-cells3,4,8,10 resemble immunoblasts or Hodgkin cells; multinucleate forms may be present. However, Reed-Sternberg cells are not seen. The vessel walls are infiltrated by lymphocytes, which may result in infarct-like tissue necrosis. Fibrinoid necrosis of vessel wall is common. Despite the name, granulomas are not a feature. There may be progression to EBV-positive DLBCL.
Grading:
grade 1: no or few (less than 5 per HPF) EBV-infected cells. Clonality is difficult to demonstrate.
grade 2: scattered (less than 5 to 20 per HPF) EBV-infected cells. There may be foci of necrosis, but the infiltrate is polymorphous.
grade 3: sheets of EBV-infected cells, necrosis and cellular monomorphism. This may be considered a type of DLBCL.
Skin lesions1 consist of red dermal papules or subcutaneous nodules. The histology mirrors that seen in the lungs. They consist predominantly of CD4+ T-cells. The infiltrate is angiodestructive and necrosis occurs. EBV-positive cells are harder to demonstrate than in the lungs. A few patients have white atrophic plaques in which EBV-positive cells are not demonstrable.
|
negative |
||
|
usually positive |
||
|
variably positive |
||
|
may be aberrantly expressed by the atypical B-cells4 |
||
|
may be aberrantly expressed by the atypical B-cells4 |
||
|
variably positive |
||
|
positive in the larger atypical / pleomorphic cells |
||
extranodal NK/T-cell lymphoma, nasal type, which is also often angiodestructive and is associated with EBV. The pattern of necrosis is similar to that of LYG5. The EBV-positive cells have an NK cell immunophenotype, being negative for B-cell markers. LYG is rare in the nasal region but may occur in the oral cavity.
Enteropathy-associated T-cell lymphoma
Acute T-cell lymphoblastic leukaemia
World Health Organization Classification of Tumours, Tumours of the haematopoietic and lymphoid tissues, IARC Press 2001.
0 Tumours of the Lung, Pleura, Thymus and Heart. WHO Classification of Tumours. IARC Press 2004.
This page last revised 21.6.2005.
©SMUHT/PW Bishop