Subcutaneous phaeohyphomycosis of the scalp-a rare fungal infection treated by excision

Fungal infections are known to occur in immunecompromised individuals. Most are treated by antifungal chemotherapeutic agents either by local m e a s u r e s o r b y s y s t e m i c t r e a t m e n t . Phaeohyphomycosis, derived from the Greek language meaning dark fungi with hyphae, is a rare condition. We describe what we believe is the first ever case report of phaeohyphomycosis in the occipital region of the scalp which mimicked a dermoid cyst.


Introduction
Fungal infections are known to occur in immunecompromised individuals.Most are treated by antifungal chemotherapeutic agents either by local m e a s u r e s o r b y s y s t e m i c t r e a t m e n t .Phaeohyphomycosis, derived from the Greek language meaning dark fungi with hyphae, is a rare condition.We describe what we believe is the first ever case report of phaeohyphomycosis in the occipital region of the scalp which mimicked a dermoid cyst.

Case report
A 23 year old male presented with a 3 year history of a painless scalp swelling in the occipital region.He had had a history of trivial head trauma.He did not suffer from medical illnesses and had no previous surgical procedures.The swelling was 3 cm in diameter and situated over the midline of the occipital region, just above the occipital protuberance.It was soft, cystic in consistency and had a smooth surface.The lump was in the subcutaneous plane, mobile and was not transilluminant.There was no cough impulse or bony indentation.The provisional diagnosis was dermoid cyst of the scalp.Fine needle aspiration cytology assessment was undertaken and reported as an epidermoid cyst.A computed tomography image of the skull was taken which revealed a hypo dense soft tissue swelling over the occipital region of the scalp, probably dermoid cyst (Figure 1).Under local anesthesia, the swelling was excised completely and sent for histopathological examination.
The histopathological examination report was a fibrocollagenous tissue with clusters of pigmented fungal hyphae infiltrating into the fibrocollagenous t i s s u e , s u g g e s t i v e o f a s u b c u t a n e o u s phaeohyphomycosis (Figure 2).We were not able to find the causative species as the specimen was fixed in formalin after excision.

Discussion
In 1983, McGinnis introduced the concept of phaeohyphomycosis [1]."Phaeo" is a Greek word which means "dark" and "hypho" stands for "fungi with hyphae" [2].Phaeohyphomycosis is a fungal infection caused by dematiaceous fungi or melanised fungi, since group of fungi has melanin in their cell wall.Wangiella dermatitidis, alternaria, curvularia, cladophialophora and expholia jeanselmei are the common species causing phaeohyphomycosis.
Phaeohyphomycosis is a rare disease.In 2002, Sharma et al. reported 23 cases of subcutaneous phaeohyphomycosis in India [3].In Malawi, O Donnell PJ et al. reported nine cases of subcutaneous phaeohyphomycosis in extremities [4].In Brazil, Correspondence: V. Arunagiri E-mail: surgeonvarun@yahoo.comThe clinical presentation of subcutaneous phaeohyphomycosis is a painless swelling, which is cystic to firm in consistency in the subcutaneous plane and is common in immunocompromised patients.Usually the diagnosis is made after excision with the histopathological examination as in this case.Treatment is by surgical excision.Itraconazole in the postoperative period has shown promising results in the treatment of subcutaneous phaeohyphomycosis both in immuno-compromised and normal patients

Key Points:
F Phaeohyphomycosis is a rare fungal infection which presents as a painless swelling .F This condition occurs commonly in individuals who are immunocompromised.
F Dermoid cyst is a differential diagnosis.
F Treatment is by surgical excision and treatment with itraconazole.

Figure 1 .
Figure 1.Computerised tomogram of the brain showing a hypodense lesion in the subcutaneous plane of the occipital region (arrow) -this is subcutaneous phaeohyphomycosis mimicking a dermoid cyst

Figure 2 .
Figure 2. Subcutaneous phaeohyphomycosis -dematiaceous mold under low power light microscopy (A).B,C,D are high power light microscope images of the characteristic brown pigmented hyphae (B) and neutrophils (C) .D shows fungus stained with per-iodic acid Schiff diastase stain.