Urothelial carcinoma-invasive
Microcystic variant

Author: Rugvedita Parakh, M.D. (see Authors page)

Revised: 18 July 2016, last major update December 2014

Copyright: (c) 2003-2016,, Inc.

PubMed Search: Microcystic variant urothelial
Cite this page: Microcystic variant. website. Accessed October 28th, 2016.
Definition / General
  • Predominant features of urothelial carcinoma, but with prominent inter- or intracellular lumens and no true glands
  • Cyst-like structures may be due to ability of urothelium to form and line spaces (as occurs in bladder)
  • May also be due to cell degeneration (based on presence of luminal debris and necrotic cells)
Clinical Features
  • Uncommon variant associated with high stage and high grade tumors (Br J Urol 1997;79:722)
  • Report as “urothelial carcinoma with microcystic differentiation”
Case Reports
Micro Description
  • Prominent intercellular or intracellular lumens / microcysts surrounded by neoplastic urothelial or squamous cells
  • Lumens are usually empty, but may contain granular eosinophilic debris, necrotic cells or mucin
  • Cysts vary in size, are round/oval, up to 2 mm; are lined by urothelium, flattened cells or low columnar cells, but not colonic epithelium or goblet cells (Am J Clin Pathol 1991;96:635)
  • Cysts are infiltrative and may invade the muscularis propria
  • Pattern resembles cystitis glandularis et cystica
  • Also elongated, irregular branching spaces
  • May rarely have neuroendocrine differentiation (Virchows Arch 2009;454:223)
Micro Images

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Urothelial carcinoma with gland-like lumina (H&E and Alcian blue)

Urothelial carcinoma with gland-like lumina (H&E and mucicarmine)

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Multicystic and papillary architecture

Lumens contain PAS+ material (hematoxylin-eosin)

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Signet-ring cells present in walls of cysts

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Tumors of renal pelvis

Differential Diagnosis
  • Adenocarcinoma: diffusely lined by goblet cells or intestinal cells, not flattened urothelial-like cells; usually deeply invasive, high grade
  • Cystitis cystica / glandularis: glands in lamina propria lined by columnar, cuboidal or intestinal epithelium; no atypia, mitotic figures or necrosis
  • Mucoid cytoplasmic inclusions: present in up to 37% of urothelial carcinomas, often high grade (Hum Pathol 1992;23:860)
  • Müllerianosis: presence of 2 of 3 (endocervicosis, endometriosis or endosalpingiosis); no atypia, no mitotic figures
  • Nephrogenic metaplasia / adenoma: small hollow tubules similar to mesonephric tubules, usually lined by single layer of bland cuboidal or hobnail cells, surrounding eosinophilic or basophilic secretions; typically not cystic, no/minimal atypia or mitotic figures; no true invasion
  • Urothelial carcinoma with glandular differentiation: similar, but has true glands lined by goblet cells or colonic epithelium; is primarily a urothelial tumor, in contrast to adenocarcinoma
  • Urothelial carcinoma, nested variant: may have focal tubular differentiation