case_images: PMC11732275_01
case_images: Clinical appearance of pigmentation of the lip, labial mucosa, and vermilion border.
case_images: CRID2025-4265486.001.jpg
case_images: PMC11732275_01_CRID2025-4265486.001.jpg
case_images: fig1
case_images: On examination, multiple well-demarcated, superficial, dark brown macules measuring 4*2 mm are seen on the lips, adjacent labial mucosa, and vermilion border of the upper and lower lips (Figures 1, 2, and 3).
case_images: Clinical appearance of pigmentation of the lip and labial mucosa.
case_images: CRID2025-4265486.002.jpg
case_images: PMC11732275_01_CRID2025-4265486.002.jpg
case_images: fig2
case_images: On examination, multiple well-demarcated, superficial, dark brown macules measuring 4*2 mm are seen on the lips, adjacent labial mucosa, and vermilion border of the upper and lower lips (Figures 1, 2, and 3).
case_images: Clinical measurements of pigmentations.
case_images: CRID2025-4265486.003.jpg
case_images: PMC11732275_01_CRID2025-4265486.003.jpg
case_images: fig3
case_images: On examination, multiple well-demarcated, superficial, dark brown macules measuring 4*2 mm are seen on the lips, adjacent labial mucosa, and vermilion border of the upper and lower lips (Figures 1, 2, and 3).
case_images: Histological H&E image showing mild acanthosis and abundant melanin in the basal layer without hyperplasia.
case_images: CRID2025-4265486.004.jpg
case_images: PMC11732275_01_CRID2025-4265486.004.jpg
case_images: fig4
case_images: Furthermore, the colonoscopy did not reveal any abnormalities (Figure 4).