| • | AKA lymphocytoma cutis; cutaneous lymphoid hyperplasia; Speigler-Fendt sarcoid |
| • | most cases, cause unknown |
| • | clinically = purple plum |
| • | face, chest, and upper extremities |
histology:
| • | by definition, composed of nodular collections of mature B lymphocytes |
| • | infiltrate tends to favor papillary dermis (“top heavy”) |
| • | monomorphous infiltrate with atypical cells |
| • | epidermal, adnexal and vascular infiltration |
| • | “bottom heavy” pattern of infiltration |
| • | dissection of lymphoid cells between collagen bundles |
| • | poor circumscription of lymphoid aggregates |
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| • | a patchy rather than a heavy diffuse infiltrate |
| • | germinal centers containing “tingible body” macrophages |
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Immunohistochemistry:
Borrelial Lymphocytoma Cutis
| • | distribution classically: earlobe, areola, nose, scrotum (i.e. low skin temperature) |
| • | check serum antibody titer of B. burgdorferi (elevated in 50%) |
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