lymphomatoid papulosis

^[1]

Introduction

Asymptomatic, chronic, self-healing polymorphous eruption.

idiopathic
considered to be a low grade lymphoma or a pseudolymphoma involving T-helper cells without systemic involvement

lesions limited to skin
low, but real risk of malignant transformation
- occasional progression to Hodgkin's disease or cutaneous T-cell lymphoma
superficial or deep, perivascular or interstitial mixed cell infiltrate
- atypical cells may comprise 50% of infiltrate
- large, atypical histiocytic lymphocytes; occasional Reed-Sternberg like cells
- smaller, atypical lymphocytes
epidermis:
- focal spongiosis
- mild exocytosis
- necrotic keratinocytes
- extravasated erythrocytes are frequent
small vessel lymphocytic vasculitis (10%)

generally asymptomatic
occasionally lesions are pruritic, tender or painful
NO weight loss, fever, night sweats
lesions appear in crops of recurrent, self-healing eruptions
lesions may resolve spontaneously at any point in their evolution
some lesions may persist & produce scarring
individual lesions evolve over 2-8 week period
primary lesions are erythematous to red-brown with central hemorrhage & necrosis (black)
lesions are papular with diameter 2 mm to 3 cm, a few to hundreds in number
lesions are usually random, but may be grouped
lesions occur primarily on trunk & extremities; rarely on oral or genital mucosa
lesions may ulcerate
atrophic scars may persist
post-inflammatory hyperpigmentation or hypopigmentation may occur

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