Vasculitis and Cryoglobulinemia

1. intravascular cryoprecipitation and hyperviscosity (non-inflammatory, as regards significant cellular infiltrates)

2. activated complement system

3. phagocytosis of proteinaceous material

a. related to size of aggregates

b. phagocytic ability of R-E system or mesangium

S8C24VA6-1: Abnormal proteins of the blood under special conditions may precipitate and occlude blood vessels. The precipitates histologically may have a proteinaceous quality; the patterns may be relatively free of inflammatory infiltrates. For some examples, the patterns are associated with inflammatory infiltrates; they then qualify as a leukocytoclastic angiitis.

Vasculitis and Cryoglobulinemia

1. single component (monoclonal immunoglobulin)

a. myeloma

b. Waldenstrom’s macroglobulinemia

c. primary phenomenon

Vasculitis and Cryoglobulinemia

1. mixed component

a. rheumatoid arthritis

b. systemic lupus erythematosus

c. atypical lymphomas

d. infections

e. liver disease

f. endomyocardial fibrosis

S8C24VA6-4: Disorders that may be associated with cryoglobulinemia of mixed type are listed.

Lymphocytic Capillaritis

1. histologic requisites

a. extravasated red blood cells

b. lichenoid epidermal response (+/-)

c. hemosiderosis

2. syndromes (purpura pigmentosa progressiva)

S8C24P6-5: Histologic features of lesions in the category of the progressive pigmented purpuras are listed.

Hyalinizing Angiopathies

1. lupus erythematosus

2. porphyria cutanea tarda

3. erythropoietic protoporphyria

4. diabetes mellitus

5. amyloidosis

S8C24VA6-6: Hyalinization of the walls of vessels is a common finding in some disorders. Examples are listed.