Talk:Lymph node pathology

Castleman's disease

Microscopic description

A, B. The sections show lymphoid tissue with small, round germinal centers, that have hyaline material and are devoid of mitotic activity. The germinal centers are surrounded by markedly enlarged, concentric, "onion skin"-like mantle zones. The mantle zones are penetrated by large hyalined vessels, extending from the interfollicular zones to the germinal centers, and with the mantle zone form "lolli-pop"-like structures. Some mantle zones enclose two germinal centers. The sinuses are effaced and partially replaced by hyaline material.

The elastic trichrome stain demonstrates collagen between the follicles and around intermediate-sized blood vessels. The PAS stain marks the intermediate-sized vessels that penetrate the mantle zone.

D2-40 and CD21 immunostaining demonstrate a mesh-like network within the mantle zone and within the compact germinal centers. Cyclin D1 immunostaining shows rare, small, scattered lymphoid cells. BCL2 immunostaining marks the cell membrane of the mantle zone lymphocytes and intrafollicular lymphocytes, but does not stain cells within the germinal centers. The FDC stain is non-contributory.

Final diagnosis

A. Axillary mass, right suprascapular, excision - features consistent with Castleman disease, hyaline vascular variant.

B. Axillary mass, right deep, excision - Castleman disease, hyaline vascular variant.

Sinus histiocytosis

Microscopic description

The section shows a lymph node with sinus histiocytosis and prominent secondary follicles with germinal centers that contain numerous tingible body macrophages. The sinus histiocytes have a normal sized nucleus and no emperipolesis is identified with routine stains. Rare eosinophils and neutrophils are found among the sinus histiocytes. There are no granulomas and no necrosis is identified.

Final diagnosis

A. Lymph node, angle of mandible, excision - Lymph node with reactive sinus histiocytosis.