Chromoblastomycosis with malignant transformation and cutaneous-synovial secondary localization. The potential therapeutic role of itraconazole

Chromoblastomycosis in Latin America and the Caribbean: epidemiology over the past 50 years

Chromoblastomycosis is a chronic disease caused by melanized fungi that mainly affect individuals performing soil-related labour. The objective of this study was to analyse the epidemiological and clinical characteristics of chromoblastomycosis in Latin America and the Caribbean by an extensive literature review. An integrative review was performed of English, French, Portuguese, and Spanish publications in LILACS, SciELO, PubMed, SCOPUS and Web of Science databases covering the period 1969-2019. A total of 1,211 articles were identified, of which 132 were included in the review, covering 2,081 patients, 80.3% were male, the mean age was 56.1 years. The mean duration of the disease was 10.8 years. The lesions were mainly described in the lower limbs (60%). The most frequent clinical forms were verrucous (46.4%) and tumorous (21.7%). Major disease symptoms and signs consisted of itching and pain. Bacterial infection and functional limitation were important complications. Immunosuppression post-kidney transplantation was the most frequent comorbidity while leprosy was the main concomitant infectious disease. Fonsecaea pedrosoi and Cladophialophora carrionii were the predominant etiological agents. Majority of the cured cases were treated with itraconazole as monotherapy or in combination with other antifungals, surgery or cryosurgery. Chromoblastomycosis affects hundreds of rural workers in Latin America and the Caribbean, causing disability and personal, family and economic losses. It is important to prioritize epidemiological surveillance and early diagnosis of this disease in order to reveal its real prevalence and direct resources to preventive actions, diagnosis and early treatment.

LAY SUMMARY

Chromoblastomycosis is a slowly progressing chronic disease caused by melanized fungi. We collected data from South America and the Caribbean covering 1969-2019, the 132 articles included 2 081 patients, mean disease duration was 10.8 years. Fonsecaea pedrosoi and Cladophialophora carrionii predominated.

Chromoblastomycosis

Chromoblastomycosis (CBM), also known as chromomycosis, is one of the most prevalent implantation fungal infections, being the most common of the gamut of mycoses caused by melanized or brown-pigmented fungi. CBM is mainly a tropical or subtropical disease that may affect individuals with certain risk factors around the world. The following characteristics are associated with this disease: (i) traumatic inoculation by implantation from an environmental source, leading to an initial cutaneous lesion at the inoculation site; (ii) chronic and progressive cutaneous and subcutaneous tissular involvement associated with fibrotic and granulomatous reactions associated with microabscesses and often with tissue proliferation; (iii) a nonprotective T helper type 2 (Th2) immune response with ineffective humoral involvement; and (iv) the presence of muriform (sclerotic) cells embedded in the affected tissue. CBM lesions are clinically polymorphic and are commonly misdiagnosed as various other infectious and noninfectious diseases. In its more severe clinical forms, CBM may cause an incapacity for labor due to fibrotic sequelae and also due to a series of clinical complications, and if not recognized at an early stage, this disease can be refractory to antifungal therapy.

Squamous cell carcinoma derived from chronic chromoblastomycosis in Brazil

BACKGROUND

Chromoblastomycosis (CBM) is a chronic fungal infection caused mainly by the melanized fungi Fonsecaea species. The chronic lesions may be predisposed to develop into cancer, the most serious complication of the disease.

METHODS

In this report, 7 cases of squamous cell carcinoma (SCC) resulting from chronic CBM in patients from Maranhão in the Brazilian Amazon are described.

RESULTS

The 7 patients presented with SCC that resulted from chronic CBM, caused by Fonsecaea species >10 years' duration. The malignant lesions occurred independent of the antifungal therapy and all patients underwent curative amputation, except for 1 patient who developed metastases in the inguinal and intra-abdominal lymph nodes and thigh muscles. A majority of previous reports have focused on the malignant transformation of CBM described in only 1 patient each. This is a first report describing a group of patients from a single Brazilian state.

CONCLUSIONS

Here, we provide new epidemiologic data on malignant CBM lesions, an endemic disease that is seemingly neglected worldwide. We reinforce the idea that typically chronic lesions may be predisposed to turn malignant.

Invasive squamous cell carcinoma arising from chromoblastomycosis

Chromoblastomycosis is a chronic subcutaneous mycosis seen mainly in tropical regions. While malignant transformation rarely occurs, the present report describes a 69-year-old man with a 21-year history of chromoblastomycosis complicated by invasive squamous cell carcinoma requiring amputation of the affected limb. A review of previous reported cases shows malignancy arising after 20-30 years of infection in ≥60-year-old males who have received inadequate treatment of chromoblastomycosis and have had relapses. An immunocompromised state is not an associated feature of such cases. The extremities are commonly affected as carcinomas occur from the most chronic lesions which are generally found on these limbs.

Granulomatous reaction and tissue remodelling in the cutaneous lesion of chromomycosis

The cell-mediated immune reaction was studied in the cutaneous lesion of chromomycosis, using monoclonal antibodies against polymorphonuclear neutrophils, macrophage and lymphocyte subsets, endothelial and fibroblast cells. In addition, immunostaining of the main degradative enzymes (neutrophil elastase and interstitial collagenase) and certain important cytokines (transforming growth factor-beta, tumour necrosis factor-alpha and interferon-gamma) suggested an explanation for the granulomatous reaction and the associated tissue remodelling. The distribution pattern of neutrophils and macrophage subsets, observed by computer-aided image analysis, suggests that the in situ persistence of fungi is the main pathological factor.