Urothelial (Transitional Cell) Carcinoma with Chordoid Features

Definition

• Subtype of urothelial carcinoma with abundant myxoid stroma

Alternate Name

• Urothelial carcinoma with abundant myxoid stroma (some cases)

Diagnostic Criteria

• Invasive urothelial carcinoma with abundant myxoid stroma
  • Faintly basophilic stroma
    • Alcian blue positive, mucicarmine faint
• Carcinoma cells arranged in cords
  • Reminiscent of chordoma or extraskeletal myxoid chondrosarcoma
  • Scant cytoplasm
  • May have microcystic pattern
• Stromal change may be focal or predominant

Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342

Original posting/updates: 10/20/12

Supplemental studies

Immunohistology

• High molecular weight keratin, p63 positive
• Negative for: brachyury, glypican 3, calponin, S100, GFAP

Histochemistry

• Mucin stains may reveal intracytoplasmic lumens

Differential Diagnosis

• Fibromyxoid Nephrogenic Adenoma

  Nephrogenic Adenoma with Fibromyxoid Stroma	Urothelial Carcinoma with Chordoid Features
  Areas of typical nephrogenic adenoma (papillae and tubules lined by single layer of cuboidal cells)	Areas of usual transitional carcinoma
  p63 negative	p63 positive

  In the fibromyxoid areas these may be identical
  
  
• Adenocarcinoma
• No glandular differentiation in chordoid urothelial carcinoma
• Yolk sac tumor
  • Glypican 3 negative in chordoid urothelial carcinoma
• Mesenchymal lesions with myxoid patterns
  • All are essentially ruled out by identification of areas of usual urothelial carcinoma
  • Inflammatory myofibroblastic tumor
    • Actin positive, p63 negative
      • Both are keratin positive
  • Extraskeletal myxoid chondrosarcoma
    • Keratin, p63 negative
  • Myoepithelioma/mixed tumor
    • Actin, calponin, GFAP positive

Grading / Staging

Grading

• Plasmacytoid carcinoma is definitionally high grade

Staging

• Node involvement and peritoneal surface spread are common
• Although non-invasive papillary urothelial neoplasms are technically in situ, they are staged as Ta and are not referred to as carcinoma in situ
• If possible, the extent of lamina propria / submucosa invasion should be reported
• Muscularis mucosae is variable and its involvement does not affect staging
  • Generally loose strands of muscle
• Muscularis propria involvement is significant and should be evaluated carefully
  • Dense, well defiined bundles of muscle
  • Depth of muscularis propria involvement cannot be assessed in transurethral specimens
  • Presence or absence of propria should be reported even if not involved
• Lymphatic invasion should be confirmed by immunohistochemistry
  • Pseudovascular tissue retraction is common

Clinical

• Appears to be an aggressive variant of urothelial carcinoma
  • Frequently presents with nodal metastases

Classification / Lists

Flat Lesions of the Urinary Bladder

• Flat urothelial hyperplasia
• Reactive urothelial atypia
• Atypa of unknown significance
• Dysplasia
• Urothelial carcinoma in situ

Papillary Lesions of the Urinary Bladder

• Nephrogenic adenoma
• Fibroepithelial polyp
• Polypoid/papillary cystitis
• Papillary urothelial hyperplasia
• Urothelial papilloma
• Papillary urothelial neoplasm of uncertain malignant potential (PUNLUMP)
• Low grade urothelial carcinoma
• High grade urothelial carcinoma

Subtypes of High Grade Urothelial Carcinoma

• Micropapillary urothelial carcinoma
  
• Plasmacytoid urothelial carcinoma
• Small cell carcinoma
• Urothelial carcinoma with chordoid features
• Urothelial carcinoma with sarcomatoid differentiation
• Urothelial carcinoma with squamous differentiation
  

Inverted Lesions of the Urinary Bladder

• Florid hyperplasia of von Brunn nests
• Cystitis cystica/glandularis
• Inverted urothelial papilloma
• Inverted urothelial carcinoma
• Nested variant urothelial carcinoma
• Verrucous squamous carcinoma

Glandular Lesions of the Urinary Bladder

• Nephrogenic adenoma
• Cystitis cystica/glandularis
• Intestinal Metaplasia
• Villous adenoma
• Urothelial carcinoma with glandular differentiation
• Nested urothelial carcinoma with cystic structures
• Non-urachal adenocarcinoma
• Mulllerian lesions
  • Endometriosis
  • Endocervicosis
  • Endosalpingosis
• Urachal lesions
  • Urachal remnant
  • Urachal adenocarcinoma
• Metastatic/direct spread of non-bladder adenocarcinomas

Bibliography

• Murphy WM, Grignon DJ, Perlman EJ. Tumors of the Kidney, Bladder and Related Urinary Structures, Atlas of Tumor Pathology, AFIP Fourth Series, Fascicle 1, 2004
• Eble JN, Sauter G, Epstein JI, Sesterhenn IA eds. World Health Organization Classification of Tumors. Pathology and genetics of tumors of the Urinary System and Male Genital Organs. IARC Press: Lyon 2004.
• Cox RM, Schneider AG, Sangoi AR, Clingan WJ, Gokden N, McKenney JK. Invasive urothelial carcinoma with chordoid features: a report of 12 distinct cases characterized by prominent myxoid stroma and cordlike epithelial architecture. Am J Surg Pathol. 2009 Aug;33(8):1213-9
• Tavora F, Epstein JI. Urothelial carcinoma with abundant myxoid stroma. Hum Pathol. 2009 Oct;40(10):1391-8.