it is a mycotic disease caused by melanin containing fungus , characterized by the presence of dematiaceous ( dark - walled ) septate hyphae , pseudohyphae and sometimes yeast or a combination of all these in tissue . it is a saprophyte found in soil , wood and plant material in tropical and subtropical areas . subcutaneous infection results from invasive traumatic injury usually in immunocompromised individuals . most of the time , diagnosis is unsuspected and delayed because of its rarity and varied presentation . we report a case of subcutaneous phaeohyphomycosis of foot in immunocompetent patient presenting as a post traumatic chronic non healing ulcer of 2 years duration . a 46 year old lady , resident of urban delhi , presented with non healing ulcer over left foot since two years . she met a road traffic accident 23 years back and had avulsion injury of dorsum of left foot and had skin grafting over the dorsum of foot , with amputation of great toe . apparently , it was healthy till 13 years and thereafter she started having recurrent breakdown of graft , which subsided after taking local wound care . she presented to our department with complaints of non - healing painful ulcer since 2 years , which was not responding to previous medications . enzyme - linked immunosorbent assay ( elisa ) for human immunodeficiency virus -1 and 2 ( hiv-1 and hiv-2 ) were non - reactive and viral marker study was negative for hepatitis - b and hepatitis - c infection . clinically , it was suspected as tubercular versus carcinomatous ulcer because of its longer duration . local wide excision was done and tissue was sent for histopathological initially , and later for mycological examination after histopathological diagnosis of phaeohyphomycosis . excised tissue sections were stained with hematoxylin and eosin [ figure 1 ] , gomori 's methenamine silver ( gms ) stains [ figure 2 ] and periodic acid - schiff [ figure 3 ] . sections stained by hematoxylin and eosin showed dark brown pigmented hyphal elements along with yeast like spores surrounded by mixed inflammatory infiltrates , epitheloid cells , and multinucleated giant cells . pigmented septate hyphae with diffuse chronic inflammatory infiltrates ( hematoxylin and eosin stain , 40 ) dark pigmented fungal hyphae ( gomori 's methenamine silver stain , 40 ) pigmented septate fungal hyphae ( periodic acid - schiff stain , 40 ) special staining by periodic - acid - schiff and gms stains demonstrated numerous darkly pigmented , septate , hyphal fragments admixed with yeast like spores consistent with the diagnosis of phaeohyphomycosis . histopathological examination of serial sections and margins of ulcer tissue have shown no evidence of dysplasia or carcinomatous changes . ziehl - nielsen staining was done for acid fast bacilli and it was negative for tubercle bacilli . since wide excision biopsy was sent in formalin , no ulcer tissue was left to perform mycological study to find out species . however , swab cultures and tissues taken from post - operative resected margins were sent for mycological examination . direct potassim hydroxide - koh ( 10% ) mount was prepared and no hyphae or budding yeast cells were seen . tissue was sub cultured on three culture media  sda ( sabouraud 's dextrose agar ) with gentamycin , sda without gentamycin and pda ( potato dextrose agar ) , and incubated for three weeks at 37c and 22c and no growth was seen . at present , she is on antifungal treatment with tab itraconazole 400 mg daily for 3 weeks with tapering dosage to 200 mg daily for 2 weeks and final dose of 100 mg daily for 1 month . there are three types of mycosis by dematiaceous fungi , namely , phaeohyphomycosis , chromoblastomycosis and mycetoma . phaeohyphomycosis is a rare cutaneous , subcutaneous or systemic infection that contains brown pigmented mycelial elements in tissue , which differs from the chromoblastomycosis and mycetoma by absence of sclerotic cells and grains . these fungi are often found in soil , wood and plant as saprophytes in tropical and subtropical areas . it is more commonly found in northern and southern part of india , which provide ideal environment for their growth . in india 18 melanin acts as a virulence factor because of its scavenging effects over free radicals and hypochlorite 's produced by phagocytic cells , and moreover it binds to hydrolytic enzymes . mode of transmission of infection is usually trauma in immunocompromised and immunocompetent individuals . in this case , presumed source of infection is due to inoculation of fungus while she had avulsion injury in road traffic accident . delayed presentation of symptoms may be due to dormant infective nidus under the grafted wound in this immunocompetent case , which overtime went on to become symptomatic . case report by torstrick et al . had documented a case of a slowly enlarging olecranon bursal mass due to phaeohyphomycosis after a thorn puncture wound sustained over 30 years before . another case report by kaell et al . had mentioned a case where a patient had a glass injury to the knee in childhood and several years later , this nidus was likely a source of the acute fungal arthritis observed in this case ( phaeoacremonium parasiticum ) . since it is a ubiquitous fungus with increasing incidence after trauma , it should also be remembered that it is often misdiagnosed as carcinomatous non healing ulcer . we have presented this case report to increase awareness about this rare fungal infection in immunocompetent individuals , with longer duration of trauma history . here it was previously considered as a non - healing ulcer of either tuberculous or carcinomatous type , with high level of suspicion . histopathological examination of tissue section along with special staining plays a vital role in deciding the confirmatory diagnosis of phaeohyphomycosis , which then alleviated the anxiety of patient as well as the treating clinician .
we report a case of subcutaneous phaeohyphomycosis of foot , which is a mycotic disease that produces brown pigmented hyphae , pseudohyphae and yeast form in combination . 
 the patient was immunocompetent and had injury 23 years before , and developed a non healing foot ulcer which was clinically suspected as tuberculous or carcinomatous etiology . 
 local wide excision was done and sent in formalin for histopathological examination . 
 microscopically pigmented septate , hyphae and yeast forms were identified on hematoxylin and eosin stained sections which were confirmed by special stains such as periodic acid - schiff and gomori 's methenamine silver stains .