Pathology of Intravascular Large B-cell Lymphoma
Distinctive B-cell lymphoma with Atypical Lymphoid cells inside the Blood Vessels
Intravascular Large B-Cell lymphoma is the preferred term for a distinctive of lymphoma previously described under a variety of names including malignant angioendothelimatosis, angiotropic lymphoma and intravascular lymphomatosis.
Intravascular Large B-Cell lymphoma is considered to consist of 2 types: a conventional European type and an Asian variant.
The Asian variant of intravascular large B-cell lymphoma is characterized by hemophagocytic syndrome, i.e. the clinical features include pancytopenia, hepatosplenomegaly, and rarely mass formation.
It usually lacks any neurological abnormality or skin lesions, which are typical features of classical intravascular large B-cell lymphoma.
The tumour usually affects elderly patients and is characterized by general fatigue, disorders of various organs, and elevated serum lactate dehydrogenase (LDH) and soluble interleukin-2 receptor (sIL-2R) levels.
Common symptoms include skin eruptions, neurological abnormalities, and gastrointestinal abnormalities.
Intravascular large B-cell lymphoma is an important cause of fever of unknown origin and multiple organ failure.
The skin changes and neurological symptoms are more frequent in the conventional type of Intravascular Large B-Cell lymphoma but are not rare in the Asian variant.
Neurological manifestations are primarily caused by varying degrees of ischemia due to intravascular tumour cells.
The tumour almost invariably affects only extranodal sites.
Any organ or system may be involved but most commonly it is central nervous system and skin.
Trunk, extremities and face are favoured sites.
Cutaneous manifestations usually take the form of erythematous or violaceous nodular subcutaneous masses which may ulcerate.
Microscopic features: The lesion is characterised by an accumulation of large atypical lymphocytes within the lumens of small to intermediate-sized blood vessls of the affected tissue.
The tumor cells primarily grow within the blood vessel lumina but may cause minimal extravascular infiltration around the involved vessels in some patients.
Some rare cases contain extravascular infiltrates as well.
In the skin the blood vessels in the dermis and the subcutis are almost completely occluded by atypical lymphoid cells.
These cells are larger than the endothelial cells and have high nuclear:cytoplasmic ratio.
The cell nuclei are round to oval with prominent nucleoli.
Multiple atypical mitotic figures are present.
The intravascular cells are positive for CD19, CD20, CD22 and CD79A.
The bcl2 protein is positive in these lesions.
Note: Random skin biopsy is an extreme useful tool for the diagnosis of Intravascular Large B-Cell lymphoma.
The rate of positive diagnoses is high, since sufficient specimens can be obtained easily with little invasion.
To yield positive results, the biopsy should:
(i) target a visible skin lesion, if possible;
(ii) include not only the dermis but also deeper layers, including the hypodermic adipose tissue;
(iii) be relatively large; and
(iv) should be performed at, at least, 3 different locations such as the upper arm, thigh, and abdomen
[Proposal of possible diagnostic strategy for intravascular large B-cell lymphoma--usefulness of biopsy from senile hemangioma].
Intravascular large B-cell lymphoma with involvement of the abdominal subcutis: a case report and literature review.
Intravascular large B-cell lymphoma presenting as cholecystitis and pancytopenia: case report with literature review.
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