lymphomatoid papulosis

Asymptomatic, chronic, self-healing polymorphous eruption. Etiology: 1) idiopathic 2) considered to be a low grade lymphoma or a pseudolymphoma involving T-helper cells without systemic involvement Epidemiology: 1) incidence: 1.2-1.9/million 2) affects all ages; mean age 40 years 3) affects both sexes equally 4) occurs sporadically Pathology: 1) lesions limited to skin 2) low, but real risk of malignant transformation -> occasional progression to Hodgkin's disease or cutaneous T-cell lymphoma 3) superficial or deep, perivascular or interstitial mixed cell infiltrate a) atypical cells may comprise 50% of infiltrate b) large, atypical histiocytic lymphocytes; occasional Reed-Sternberg like cells c) smaller, atypical lymphocytes 4) epidermis: a) focal spongiosis b) mild exocytosis c) necrotic keratinocytes d) extravasated erythrocytes are frequent 5) small vessel lymphocytic vasculitis (10%) Clinical manifestations: 1) generally asymptomatic 2) occasionally lesions are pruritic, tender or painful 3) NO weight loss, fever, night sweats 4) lesions appear in crops of recurrent, self-healing eruptions 5) lesions may resolve spontaneously at any point in their evolution 6) some lesions may persist & produce scarring 7) individual lesions evolve over 2-8 week period 8) primary lesions are erythematous to red-brown with central hemorrhage & necrosis (black) 9) lesions are papular with diameter 2 mm to 3 cm, a few to hundreds in number 10) lesions are usually random, but may be grouped 11) lesions occur primarily on trunk & extremities; rarely on oral or genital mucosa 12) lesions may ulcerate 13) atrophic scars may persist 14) post-inflammatory hyperpigmentation or hypopigmentation may occur Laboratory: 1) skin biopsy -> immunohistochemistry a) IL-2 receptor positive b) HLA-DR-positive c) CD30 positive d) CD4 positive 2) negative workup for systemic involvement Differential diagnosis: 1) lymphoma cutis 2) scabies 3) histiocytosis X 4) papular urticaria 5) viral exanthem Management: 1) may remit in 3 weeks or continue for decades 2) may be periods or remission or continuous repetitive outbreaks 3) no treatment is consistently effective 4) pharmaceutical agents a) corticosteroids b) carmustine (BCNU) c) tetracycline d) retinoids e) methotrexate f) chlorambucil g) cyclophosphamide h) cyclosporin i) interferon alpha-2b 5) electron-beam radiation 6) PUVA may control disease, but does NOT affect long-term prognosis

General

skin disease (dermatologic disorder, dermatopathy, dermatosis) lymphoproliferative disorder papulosis

References

Color Atlas & Synopsis of Clinical Dermatology, Common & Serious Diseases, 3rd ed, Fitzpatrick et al, McGraw Hill, NY, 1997, pg 570-71