Papillary urothelial neoplasm of low malignant potential

Papillary Urothelial Neoplasm of Low Malignant Potential

Papillary urothelial neoplasm of low malignant potential under microscope

Papillary urothelial neoplasm of low malignant potential (PUNLMP) is a type of urothelial neoplasm that occurs in the urinary bladder. It is characterized by its papillary architecture and low potential for progression to invasive cancer. PUNLMP is considered a non-invasive neoplasm and is distinct from urothelial carcinoma due to its lower risk of recurrence and progression.

Pathology

PUNLMPs are defined by their papillary structures lined by urothelial cells that exhibit minimal cytological atypia. The architecture is typically orderly, with a low degree of cellular proliferation. Unlike papillary urothelial carcinoma, PUNLMPs do not show significant nuclear atypia or mitotic activity.

Histological image of PUNLMP showing papillary structures

The diagnosis of PUNLMP is primarily based on histological examination of tissue obtained via transurethral resection. Pathologists look for the presence of papillary fronds with a fibrovascular core and a urothelial lining that lacks the significant atypia seen in higher-grade lesions.

Clinical Presentation

Patients with PUNLMP often present with hematuria, which is the presence of blood in the urine. This symptom prompts further investigation, typically starting with urinalysis and cystoscopy. During cystoscopy, PUNLMPs appear as papillary lesions projecting into the bladder lumen.

Management

The management of PUNLMP involves complete resection of the lesion via transurethral resection. Regular follow-up with cystoscopy is recommended due to the potential for recurrence, although the risk of progression to invasive cancer is low.

Prognosis

The prognosis for patients with PUNLMP is generally favorable. The risk of progression to muscle-invasive bladder cancer is low, and the overall survival rate is high. However, recurrence can occur, necessitating regular surveillance.

Molecular Characteristics

Expression of p53 in urothelial neoplasms

Molecular studies of PUNLMP have shown that these lesions often lack the genetic alterations seen in higher-grade urothelial carcinomas. For example, alterations in the TP53 gene, which are common in high-grade urothelial carcinoma, are typically absent in PUNLMP.

Related Pages

• Urothelial carcinoma
• Bladder cancer
• Hematuria
• Cystoscopy