Purely Intramuscular Giant Epidermoid Cyst of the Temporalis Muscle

Introduction

An 18-year-old lady presented with a right temporal region swelling that was progressively increasing over several years duration. There was no history of trauma, and the lesion was nontender, soft, noncompressible, not attached to skin, approximately 10 × 9 cm in size and showed no transillumination. The skin over the swelling was normal and the lesion became slightly less prominent when the patient clenched her teeth indicating that it was probably below the temporalis fascia. Magnetic resonance imaging (MRI) scans showed a well-demarcated T2 hyperintense and T1 hypointense lesion within the substance of the temporalis muscle ([Fig.’1A] [C]). The underlying skull was normal, and the lesion had no intracranial extension. There was no enhancement on administration of contrast. There was diffusion restriction of the lesion on diffusion-weighted imaging (DWI) sequences ([Fig. 1D]).

Fig. 1 Magnetic resonance imaging showing an encapsulated well-defined lesion, with no intracranial extension in right temporalis muscle (A). The lesion is hypointense to the muscle on T1 sequences and hyperintense to the muscle on T2 axial (B) and coronal images (C). It shows diffusion restriction on diffusion-weighted imaging sequences (D). Intraoperative images showing (E) lesion to be beneath the temporalis fascia; (F) cheesy material and hair seen after the capsule is opened while piecemeal removal is carried out. The cut edges of the temporalis muscle are shown (blue arrows); and (G) temporalis fascia resutured after complete removal of lesion with capsule.

The patient underwent excision of the lesion under general anesthesia. Intraoperatively the lesion was within the substance of the thinned out right temporalis muscle and was accessed after opening the temporalis fascia ([Fig. 1E]). It had a firm capsule that was opened and cheesy toothpaste like material and strands of hair were removed piecemeal from inside the lesion ([Fig. 1F]). The cyst wall was then easily separated off the muscle fibers and total removal was achieved with closure of the temporalis fascia ([Fig. 1G]). Histopathology was reported as an epidermoid cyst. Her postoperative course was uneventful.

Informed Consent

Received.

Publikationsverlauf

Artikel online veröffentlicht:
31. August 2023

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