Connective tissue nevus—Isolated collagenoma

Abstract

Dear editorAn 8-years-old boy presented with a single skin-colored plaque the size of a pea on the left lumbar rib cage 2 weeks after birth. He came to the dermatology department because the rash had grown to the size of a palm with age. None had a family history, no history of trauma and medication. Dermatologic examination: skin-colored plaque on the left side of the lumbar rib cage, measuring about 11 cm × 13.5 cm, with a rough surface and several subcutaneous plaques of different sizes distributed in local clusters, partially fused, soft and without pressure pain (Figure 1A). Reflective confocal microscopy showed mild epidermal thickening in the lesion area, with approximately normal intraepidermal structures and subdermal fibrous tissue hyperplasia (Figure 1B). Dermatoscopy showed scattered brown pigmented spots and pigmented network with unclear borders visible under the microscope (Figure 1C). Histopathology showed no abnormality in the epidermis and increased, thickened, and disorganized collagen fiber bundles in the dermis (Figure 2A). Masson trichrome staining showed a significant increase in blue collagen fibers (Figure 2B). Elastic staining showed a significant decreased in elastic fibers (Figure 2C). Diagnosis is isolated collagenoma (IC). The family refused surgical treatment. F I G U R E 1 (A) General photo showed: skin-colored plaque on the left side of the lumbar rib cage, measuring about 11 cm × 13.5 cm, with a rough surface and several subcutaneous plaques of different sizes distributed in local clusters, partially fused, soft and without pressure pain. (B) Reflective confocal microscopy showed: mild epidermal thickening in the lesion area, with approximately normal intraepidermal structures and subdermal fibrous tissue hyperplasia. (C) Dermatoscopy showed: scattered brown pigmented spots and pigmented network with unclear borders were visible under the microscope This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.