[Association of borderline tuberculoid leprosy and tuberculosis: A case report and review of the literature]

INTRODUCTION

In metropolitan France, nearly 20 new cases of leprosy are diagnosed each year. The incidence of tuberculosis in France is 8/100,000 inhabitants and there are very few accounts of association of these two mycobacteria. Herein we report a case of co-infection with borderline tuberculoid (BT) leprosy and disseminated tuberculosis diagnosed in metropolitan France.

PATIENTS AND METHODS

A male subject presented with diffuse painless infiltrated erythematous plaques. The biopsy revealed perisudoral and perineural lymphohistiocytic epithelioid cell granuloma as well as acid-alcohol-fast bacilli on Ziehl staining. PCR was positive for Mycobacterium leprae, confirming the diagnosis of leprosy in the BT form. The staging examination revealed predominantly lymphocytic left pleural effusion, right-central necrotic adenopathy without histological granuloma, negative screening for BK, a positive QuantiFERON-TB™ test, and a positive intradermal tuberculin reaction. The clinical and radiological results militated in favour of disseminated tuberculosis. Combined therapy (rifampicin, isoniazid, ethambutol and pyrazinamide) together with clofazimine resulted in regression of both cutaneous and extra-cutaneous lesions. This rare co-infection combines leprosy, often present for several years, and tuberculosis (usually pulmonary) of subsequent onset. The pathophysiological hypothesis is that of cross-immunity (with anti-TB immunity protecting against subsequent leprosy and vice versa), supported by the inverse correlation of the two levels of prevalence and by the protection afforded by tuberculosis vaccination. In most cases, treatment for TB and leprosy improves both diseases. Patients presenting leprosy should be screened for latent tuberculosis in order to avoid reactivation, particularly in cases where corticosteroid treatment is being given.

[Cutaneous plasmacytosis with Darier's sign in a woman of European origin]

INTRODUCTION

Cutaneous plasmacytosis is a rare skin condition first described in 1976 and it is seen mainly in patients of Asian descent. Patients usually present with multiple reddish-brown macules and nodules chiefly on the trunk and face, with clusters of well-differentiated plasma cells in the dermis. The aetiopathogenesis and nosological features of this entity remain obscure. We report herein a case of cutaneous plasmacytosis in a European middle-aged woman with presence of Darier's sign.

PATIENTS AND METHODS

A 56-year-old woman of European descent presented with asymptomatic hyperpigmented patches affecting the dorsal aspect of her trunk for at least two years. Darier's sign was present in some episodes. Cutaneous biopsy showed a moderately dense interstitial and perivascular infiltrate containing numerous well-differentiated mature plasma cells affecting the entire dermal surface. Kappa and lambda immunochemistry demonstrated polyclonal plasma cell infiltrates with absence of light-chain restriction. Immunohistochemical examination was negative for HHV-8 and Treponema pallidum spirochetes. Laboratory findings revealed hypergammaglobulinaemia with no monoclonal bands being detected on immunofixation. A diagnosis of cutaneous plasmacytosis was made. In the absence of systemic involvement initial management consisted of clinical surveillance.

DISCUSSION

The characteristic clinico-pathological features of CP allowed diagnosis of this skin condition in our patient, although it is very rarely reported in patients of European descent. The main differential diagnoses were ruled out, namely plasmacytic infiltrates related to infections and marginal B-cell lymphoma.