Urinary bladder melanosis: case report of a rare mucosal lesion

Urinary Bladder "Melanosis": A Case Report and Review of the Literature

Melanosis of the urinary bladder, so-called melanosis vesicae, is a rare condition characterized by dark, velvety bladder mucosa observed by cystoscopy examination. Up to 20 examples have been reported in the English literature, and the etiology of this disease still needs to be discovered. We present an 82-year-old woman with a history of pelvic organ prolapse-associated urinary symptoms. The patient was found to have pigmented urinary bladder mucosa on cystoscopy and underwent a total hysterectomy and bladder mucosal biopsy. Histologically, pigmented granules were evident in the bladder stroma and epithelium, highlighted by Periodic Acid-Schiff (PAS) stain, suggestive of lipofuscin in nature. We outline the diagnostic features of bladder melanosis, discuss the diagnostic mimickers, and thoroughly review the literature on the subject.

Melanosis of the Bladder: Possible Pathogenetic Mechanisms

Melanin accumulation within the bladder urothelium and/or macrophages in the lamina propria (melanosis of the bladder) is a very rare phenomenon of unknown pathogenesis. Its rarity argues for a complex, likely multifactorial, causation. We describe bladder melanosis developing after Botox therapy in an elderly woman with a history of overactive bladder, treated grade 2 uterovaginal prolapse, and episodes of urinary tract infection and speculate that one factor (probably of many) in its pathogenesis may be a derangement of local neurourothelial interactions.

The color of urine: then and now-a comprehensive review of the literature with emphasis on intracytoplasmic pigments encountered in urinary cytology

The color of urine, once considered by uroscopists to give the most important clues to the diagnosis, still can provide some diagnostic clues in modern medicine. Pigmented cells are an uncommon and surprising find in urine cytology and can at the same time provide important diagnostic clues or represent a dangerous pitfall. We present a review of the significance of pigmented cells in urine cytology. The presence of intracellular pigment granules; their color, size, shape, and variation in size and shape; as well as their staining reactions with special stains can provide useful diagnostic insight, especially when interpreted in the cytologic context (type of pigmented cell and its degree of atypicality) and patient's clinical context. The main differential diagnosis of cytoplasmic pigmented granules includes hemosiderin, lipofuscin, and melanin, each having a different pathogenesis and significance. The goal of this paper is to describe the morphological, histochemical, and ultrastructural characteristics of the pigments seen in urinary cytology, and to review the benign and malignant conditions associated with them.

Unusual case of simple urinary bladder melanosis with complete resolution

A 66-year-old man presented with a long history of recurrent attacks of urinary retention and lower urinary tract symptoms. Flexible cystoscopy showed a urethral stricture. Follow-up cystoscopy 7 years later for recurrent symptoms demonstrated unusual extensive mucosal brown to black pigmentation, which proved histopathologically to be a simple bladder melanosis. Follow-up demonstrated complete resolution over a period of 1 year with no specific treatment. In this report, we highlighted a rare bladder abnormality with uncertain natural history.

Metastasis of Malignant Melanoma to Urinary Bladder: A Case Report and Review of the Literature

Aims. Metastatic malignant melanoma of the urinary bladder is a rare clinical entity, with only twenty-three published cases to date. We present a case of this rare entity, a thorough review of the literature, and differential diagnosis of melanoma in the bladder. Methods and Results. A 55-year-old woman with a history of malignant melanoma of the right thigh, excised eight years ago, presented with back pain, fatigue, and hematuria. She underwent computed tomography (CT) scan and was found to have metastases within the liver, spleen, lungs, and urinary bladder. She underwent cystoscopy and transurethral resection of three polypoid lesions. Histologic and immunohistochemical examination revealed metastatic malignant melanoma involving bladder mucosa. Conclusions. This case illustrates the importance of including malignant melanoma in the differential diagnosis of high grade neoplasms of bladder, especially in cases where the relevant clinical history is not available.

A case of benign vesica melanosis – four-year follow-up

Benign vesica melanosis (BVM) is a rare condition with only 15 reported cases in the literature (Table 1). There is limited understanding of its aetiology. Here we present a four-year follow-up of a case of BVM in a 53-year-old Caucasian male presenting with lower urinary tract symptoms.