|Ahead of print publication
Chromoblastomycosis: Masquerading as squamous cell carcinoma
Puneet Baveja1, Gurpreet Kaur Walia1, Gourang Paliwal1, Tankala Rajkamal2
1 Department of Pathology, Armed Forces Medical College, Pune, Maharashtra, India
2 Department of Venereology, INHS Kalyani, Vishakhapattnam, Andhra Pradesh, India
|Date of Submission||14-Oct-2020|
|Date of Decision||02-Feb-2021|
|Date of Acceptance||02-Feb-2021|
Department of Pathology, Armed Forces Medical College, Pune, Maharashtra
Source of Support: None, Conflict of Interest: None
Chromoblastomycosis is a chronic fungal infection of the skin and subcutaneous tissue caused by one of several dematiaceous (naturally pigmented) fungi. Predominantly, an infection of the humid tropical and subtropical regions, chromoblastomycosis does occur in India, and its diagnosis is usually delayed due to the low level of clinical suspicion. Here, we present the case of a 65-year-old male who presented with gradually progressive raised lesions over the right thigh of 8 years' duration with a history of sustaining injury through horse tail. Dermatological examination revealed a well-defined, erythematous, verrucous plaque on the lower third of the right thigh and knee with ill-defined advancing margins. Histopathological examination of skin biopsy and potassium hydroxide preparation of material scraped from the surface of lesions showed characteristic “sclerotic bodies” of chromoblastomycosis, and the patient was started on anti-fungal drugs to which he responded very well with regression of most of his lesion.
Keywords: Chromoblastomycosis, chronic subcutaneous mycosis, histopathology, sclerotic bodies
| Introduction|| |
Chromoblastomycosis is a chronic fungal infection of the skin and subcutaneous tissue caused by one of the several dematiaceous (naturally pigmented) fungi, which is distinguished by the unique finding of muriform “sclerotic bodies” on the microscopic examination of the material from the lesions. It has a worldwide distribution but has been reported most frequently from the tropical or subtropical locations. Particularly, the high incidence reports have been reported from Brazil, Madagascar, and Costa Rica; the causative organisms have been isolated from the soil and decaying vegetation in these areas. There has been a male predominance in most series, and many affected individuals work outdoors without footwear.
| Case Report|| |
A 65-year-old male patient, farmer by occupation, presented to the skin outpatient department (OPD) of a tertiary care center with raised pigmented lesions over the right thigh of 8 years' duration. The onset was insidious, and he gave a history of sustaining injury through the horse tail before the onset of lesion. Lesions were gradually progressive in nature and had increased to its present size of 25 cm × 18 cm. He would also feel pain at the lesional site on and off. There was no history of fever, cough, hemoptysis, and weight loss. He was evaluated at remotely located hospitals initially and was given antibiotics with no regression of his lesions. Later on, he underwent a lesional biopsy which was reported as “Lupus vulgaris;” following which he was given a full course of antitubercular drugs with no response. Finally, he presented to the skin OPD of a tertiary care center, 8 years after the onset of his lesions. General and systemic examination was not contributory.
Dermatological examination revealed a well-defined, erythematous, exuberant, verrucous plaque with irregular borders measuring 25 cm × 18 cm on the lower third of the right thigh and knee [Figure 1]. The lesion had ill-defined advancing margins right leg with surface discharge, few black dots, and crusting. No bony lesion was seen on the radiological examination. Hematological investigations and biochemical tests were within the normal limits. Differential diagnosis of squamous cell carcinoma, lupus vulgaris, and subcutaneous mycosis was considered. A skin biopsy was performed which on hematoxylin and eosin stain showed extensive pseudoepitheliomatous hyperplasia [Figure 2]a, numerous neutrophilic microabscesses, and interspersed giant cells in the dermis. Dark brown, round, and septate sclerotic bodies were seen both inside and outside the giant cells [Figure 2]b. A potassium hydroxide preparation of material scraped from the surface of lesions showed similar sclerotic bodies [Figure 3]. Based on the characteristic pigmented sclerotic bodies, a diagnosis of chromoblastomycosis was made, and the patient was put on tablet itraconazole. The patient responded very well to therapy, and his lesions started reducing within a month of starting the treatment. At present, his lesions have regressed to a great extent, 3 months after the institution of antifungals [Figure 4].
|Figure 1: Warty, erythematous plaque with brownish black spots over the surface|
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|Figure 2: Hematoxylin and eosin-stained micropictographs of skin biopsy: (a) Pseudoepitheliomatous hyperplasia (×100); (b) Neutrophilic microabscess with giant cells; brownish-colored sclerotic bodies (arrows) seen inside as well as outside giant cells (×400)|
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|Figure 3: Potassium hydroxide mount showing sclerotic bodies (arrows) (×100)|
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|Figure 4: Marked regression of lesions after 3 months of itraconazole administration|
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| Discussion|| |
Chromoblastomycosis is a chronic mycotic infection of the cutaneous and subcutaneous tissues. It was first described by Max Rudlof in 1914 in Brazil. In India, sporadic cases have been reported as case reports; hence, definite incidence is not known. So far, 169 cases have been reported in the Indian literature between 1957 and 2016, with an increase in number of cases since 2012. The highest number of cases was reported in the southern part of India. The etiologic agents gain entrance through transcutaneous puncture wounds, usually by a thorn or a splinter. Less frequently, animal-associated trauma (horse buck cock's spine, insect bite or sting) or other kinds of trauma can be identified as the portal of entry of the fungus. Tissue proliferation usually occurs around the area of inoculation producing crusted, verrucous, wart-like lesions as in our case. The characteristic “sclerotic bodies” (also known as medlar bodies, muriform cells, and copper pennies) seen in these lesions were at one time thought to be budding yeast cells, are now considered to be a form of the fungus arrested between the yeast and hyphal morphology which develops as a result of acidic conditions in the involved tissues and possibly other undefined local factors.
Lesions of chromoblastomycosis are most often found on the exposed parts of the body. The most common sites involved include legs, arms, and buttocks. In the present case, the lesion occurred on the lower extremity on the thigh region. Lesions usually start as small scaly papules or nodules which are painless but may be itchy. Satellite lesions may gradually arise and as the disease develops rash-like areas enlarge and become raised irregular plaques that are often scaly or verrucous as was seen in this case. In long-standing infections, lesions may become tumorous and even cauliflower-like in appearance. Contiguous spread to the underlying bone may produce an osteolytic lesion.
Farming is the most common occupation in patients with chromoblastomycosis. Approximately 70% of cases are seen in men. The explanation for this male predominance is not clear, but men are assumed to be more commonly involved in agricultural work and are more prone to inflict injuries on themselves, thereby causing self-inoculation.
Lesions of chromoblastomycosis spread very slowly and are rarely fatal, but can be very difficult to cure. The primary complications of long-standing cases are ulceration, lymphedema, and secondary bacterial infection. Squamous cell carcinoma, a rare sequel, is reported to occur in long-standing cases. Our patient, however, showed a very good response to therapy.
Many patients in India remain undiagnosed or are misdiagnosed due to neglect on part of patient as well as ignorance about this condition on part of treating physician. Progressive nature, associated secondary changes, and delay in diagnosis can cause considerable anxiety to the patient. Treatment is difficult, and many patients are not able to afford the drugs prescribed for this condition. Early lesions respond well to surgical debridement. Systemic antifungals are required in advanced cases and include iatraconazole, terbinafine with or without flucytosine. Response to therapy may be poor in these locally advanced cases with the persistence of warty changes, hyperpigmentation, and lymphedema even after the completion of therapy.
To summarize, chromoblastomycosis is an uncommon cause of fungal infection in India. High index of suspicion is required to diagnose the case, so that early treatment can be given for complete cure of these lesions to prevent the complications.
Declaration of patient consent
The authors certify that they had obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images, and other clinical information to be reported in the journal. The patient understands that their names and initials will not be published, and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
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Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4]