Infectious Diseases in Clinical Practice:
Letters to the Editor
Infected Dermoid Cyst Presenting as Scalp Abscess
Agrawal, Amit MCh
Division of Neurosurgery, Department of Surgery, Datta Meghe Institute of Medical Sciences, Maharashtra, India
To the Editor:
Extracranial subcutaneous masses involving the scalp and/or skull in young children are uncommon lesions.1 An 8-year-old male child presented with slowly progressive swelling over left temporal region, which has been existing since he was 1 year old. For the last 1 month, the swelling was associated with pain. The child also developed pus discharge from the swelling and low-grade fever without chills and rigors. The child underwent incision and drainage for the abscess outside and started on antibiotics. Despite the drainage and a course of antibiotics, pus discharge was persisting. Local examination revealed 4 × 4-cm firm, tender, nonpulsatile swelling with indurated margins over left frontotemporal region. There was yellowish non-foul-smelling pus discharge from the swelling. Pus culture showed Staphylococcus aureus sensitive to all antibiotics. Skull radiograph showed lytic lesion involving left temporal bone with sclerotic margins (Fig. 1). Computed tomographic scan of the brain with bone window showed same lytic lesion without intracranial extension (Fig. 2). He underwent drainage of abscess with excision of cyst wall. The cystcontained cheesy material and thin, nonfoul-smelling pus. There was erosion of both the tables of calvaria, and dura was exposed. The child did well after surgery, and the wound was healed. Histopathology was suggestive of dermoid cyst.
Dermoid and epidermoid cysts are uncommon masses in the head and neck region of children, and most commonly involve the midline.2-4 Although the most common reported lesion is the dermoid cyst, but the spectrum of pathologies in these lesions can present diagnostic challenges to the treating surgeon.1,5 As in present case, skull radiographs demonstrate a lytic lesion surrounded by a sclerotic rim typical of dermoid cyst of the cranium.4 Expansion and erosion of the cranial bones are even rarer; however, these tumors may expand (1) laterally in the cranial bones, (2) externally to present as masses in the scalp or facial region, or (3) internally to involve the intracranial contents.6,7 High-risk cases can be identified by clinical and radiological features, confirmed by a computed tomographic scan, and then referred for neurosurgical treatment.6 In calvarial masses of uncertain nature, surgical excision both for diagnosis and for treatment is recommended.4 Present case signifies that scalp abscess in a child may have these types of lesions and needs further work up, histopathological confirmation, and definite treatment.
Amit Agrawal, MCh
Division of Neurosurgery
Department of Surgery
Datta Meghe Institute of Medical Sciences
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4. Martinez-Lage JF, Garcia S, Torroba A, et al. Unusual osteolytic midline lesion of the skull: benign osteoblastoma of the parietal bone. Childs Nerv Syst. 1996;12(6):343-345.
5. Peter JC, Sinclair-Smith C, De Villiers JC. The congenital bregmatic dermoid: an African cyst? Br J Neurosurg. 1992;6(2):107-114.
6. Crawford R. Dermoid cyst of the scalp: intracranial extension. J Pediatr Surg. 1990;25(3):294-295.
7. Wax MK, Briant TD. Epidermoid cysts of the cranial bones. Head Neck. 1992;14(4):293-296.
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