New clinical and histological patterns of acute disseminated histoplasmosis in human immunodeficiency virus-positive patients with acquired immunodeficiency syndrome.

Histoplasmosis has attained increasing relevance in the past 3 decades because of the appearance of the human immunodeficiency virus (HIV). In most immunocompetent persons, the infection is asymptomatic or can produce a respiratory condition with symptoms and radiological images similar to those observed in pulmonary tuberculosis; in non-HIV+ immunocompromised patients, it can cause respiratory symptoms or evolve into a disseminated infection. The same can occur in acquired immunodeficiency syndrome (AIDS) patients. We have observed a series of HIV+ patients with AIDS who presented with cutaneous histoplasmosis and in whom the clinical and histopathological features were highly unusual, including variable mucocutaneous lesions that were difficult to diagnose clinically. These patients displayed unusual, previously undescribed, histological patterns, including lichenoid pattern, nodular pseudomyxoid pattern, pyogenic granuloma-like pattern, perifollicular pattern, and superficial (S), mid (M), and deep perivascular dermatitis; and more commonly encountered patterns, such as histiocytic lobular panniculitis and focal nodular dermatitis. The novel histopathological patterns of cutaneous involvement by histoplasmosis seen in these patients resembled other common inflammatory and infectious conditions and required a high level of suspicion and the application of special stains for organisms for confirmation. These new, clinical, and histological findings do not seem to be commonly encountered in HIV- patients infected with the fungus but seem to be displayed most prominently in HIV+ patients with AIDS.