Isolated Collagenoma on the Scalp: A Rare Presentation
The present case is about a 20-year-old male patient who presented with an asymptomatic swelling on the left fronto-parieto-occipital region of the scalp since last 10 years. The swelling was insidious in onset, started as single papular lesion in the parietal region and gradually progressed to reach the present size []. Contrast enhanced computed tomography scan of the head showed that the swelling was outside the skull bones, without any intracranial extension. Patient had gone to a plastic surgeon 5 years back and had undergone partial excision of the swelling. Excised tissue was subjected to histopathological examination at that time, but the report was not available with the patient. The swelling again increased in size and attained the present size. There was no history of trauma or any manual or other manipulation at the site prior to the development of the swelling. There was no history of spontaneous regression or reduction in size. There was no history of fainting and other localizing neurological sign. There was no feature suggestive of tuberous sclerosis such as adenoma sebeceum, seizures, ash leaf macules or confetti like macules. On physical examination, a well-defined circumscribed swelling measuring 14 cm × 11 cm, presented over scalp, involving left fronto-parieto-occipital region with some extension over right []. It was firm in consistency and non-compressible with a smooth surface. The skin and hairs overlying the swelling were normal except the brownish discoloration of the skin. Linear scar of size 13.5 cm × 0.5 cm of previous surgery was present over the swelling on the left side []. Systemic examination including skin, mucosa, nail and hair did not show any abnormality. A 4 mm incisional punch biopsy at the margin of swelling was sent for histopathological examination, which showed hyperplastic epidermis with thickened reticular dermis with dense collagen bundles that were arranged haphazardly in lower reticular dermis []. A single terminal follicle showed dense perifollicular fibroplasia with an increased number of fibrocytes. Special staining with Masson's trichrome stain showed green colored collagen bundles arranged haphazardly []. As patient had cosmetics concerns so he was referred to the plastic surgery for the complete excision of the lesion in steps.