PMC9817159_01
Bladder Mucosa (Panel A): Pigmentation of bladder mucosa as seen on cystoscopy. Upper Tract Urothelium (Panel B): Upper tract urothelial pigmentation of mucosa as seen on nephoscopy.
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Inspection of the bladder during cystoscopy showed bladder mucosa that appeared blackish-brown with areas of tan that looked somewhat calcified (Fig. 1).
Melan-A and SOX10 Immunohistochemistry Stain of Bladder Biopsy: Immunostains show background melanin pigment, but are negative for Melan-A (Panel A) and SOX10 (Panel B) expression, excluding a diagnosis of malignant melanoma.
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Immunostains for Melan-A and SOX10 were negative for malignant melanoma (Fig. 2).
H&E Stain of Bladder Biopsy: Abundant black-brown granular pigment consistent with melanin present within the superficial urothelium and in macrophages in the lamina propria as seen on histologic sections of benign bladder mucosa. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)
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He underwent PCNL one month later with similar brown-black granular pigment deposition in the renal pelvis (Fig. 3).