Mai Kien T, Elmontaser Ghazi, Perkins D Garth, Yazdi Hossein M, Stinson William A, Thijssen Anthony
Division of Anatomical Pathology, Department of Laboratory Medicine, The Ottawa Hospital Civic Campus, Ontario, Canada.
BJU Int. 2004 Sep;94(4):544-7. doi: 10.1111/j.1464-4096.2004.04923.x.
To report five cases of papillary urothelial neoplasm of low malignant potential (UNLMP) and papillary urothelial carcinoma of low grade (UCLG) associated with extensive muscle invasion, and to investigate the clinical and histopathological presentation and their immunohistochemical properties.
Consecutive cystectomy and correlating transurethral resection (TUR) of urinary bladder tumour specimens were reviewed to identify cases of UCLG having extensive invasion into the urinary bladder wall. All specimens were stained immunohistochemically, as were those from 10 control cases having reactive urothelium or superficial UNLMP. The clinical charts were reviewed.
Of a total of 95 cystectomy cases there were four of UNLMP or UCLG with extensive invasion. An additional case was added from our consultation file. All five cases had biopsies misdiagnosed as benign lesions or prostatic adenocarcinoma. The superficial invasive components consisted of UCLG conforming to the previously described entities of nested transitional cell carcinoma (TCC), microcystic or deceptively benign-appearing TCC. Immunostaining for cytokeratin 20, MIB-1 and p53 was similar to reactive epithelia, whereas E-cadherin immunoreactivity was slightly different, with focal negativity compared with extensive immunoreactivity in invasive vs noninvasive UCLG. Four patients developed distant metastases; three died within a follow-up of 3 years.
UNLMP and UCLG that widely and deeply invade the bladder accounted for 4% of urothelial carcinoma (UC) in cystectomy specimens and commonly pose diagnostic problems in superficial TUR specimens. From this study with few cases the diagnosis of this entity in superficial biopsies is aided by an awareness of it and by identifying 'benign appearing' nests of urothelial cells which are deeply seated in the stroma. Immunostaining is unlikely to be very useful.
报告5例伴有广泛肌层浸润的低恶性潜能乳头状尿路上皮肿瘤（UNLMP）和低级别乳头状尿路上皮癌（UCLG），并研究其临床和组织病理学表现及其免疫组化特性。
回顾性分析连续膀胱切除标本及相关经尿道膀胱肿瘤切除术（TUR）标本，以确定UCLG广泛浸润膀胱壁的病例。所有标本均进行免疫组化染色，10例具有反应性尿路上皮或浅表UNLMP的对照病例标本也进行免疫组化染色。查阅临床病历。
在总共95例膀胱切除病例中，有4例为UNLMP或UCLG伴广泛浸润。从我们的会诊档案中又增加了1例。所有5例活检均被误诊为良性病变或前列腺腺癌。浅表浸润成分由符合先前描述的巢状移行细胞癌（TCC）、微囊性或看似良性的TCC实体的UCLG组成。细胞角蛋白20、MIB-1和p53的免疫染色与反应性上皮相似，而E-钙黏蛋白免疫反应性略有不同，与浸润性和非浸润性UCLG广泛免疫反应相比，有局灶性阴性。4例患者发生远处转移；3例在3年随访期内死亡。
广泛且深度浸润膀胱的UNLMP和UCLG占膀胱切除标本中尿路上皮癌（UC）的4%，在浅表TUR标本中通常存在诊断问题。在本病例数较少的研究中，对浅表活检中该实体的诊断可通过对其有所认识并识别位于基质深部的“看似良性”的尿路上皮细胞巢来辅助。免疫组化不太可能非常有用。
