Urachal carcinoma

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Urachal carcinoma
Diagnosis in short

Urachal carcinoma (right of image) and benign urothelium (left of image). H&E stain.

LM atypical cells - usually gland forming, +/-mucinous component, +/-signet rings
Subtypes enteric, mucinous, signet ring
LM DDx adenocarcinoma of the urinary bladder, invasive urothelial carcinoma with glandular differentiation, metastatic adenocarcinoma
IHC CK20 +ve, beta-catenin +ve (non-nuclear), p63 -ve, CK34betaE12 +ve
Site urachus, urinary bladder - specifically the dome

Signs +/-hematuria
Prevalence very rare
Prognosis usually poor
Clin. DDx other bladder tumours - esp. urothelial carcinoma

Urachal carcinoma is an uncommon malignant tumour that arises from the urachus. Most urachal carcinomas are adenocarcinomas.

General

  • Very rare[1]~ 0.2% of bladder cancers.[2]
  • Often younger <55 years-old.

Treatment:

  • Partial cystectomy +/- umbilectomy.

Gross

  • Lesion must be in urachus or dome of urinary bladder.

Microscopic

Features of epithelial malignancy:

  • Atypical (epithelial) cells.
  • Usually gland forming, i.e. adenocarcinoma.
  • +/-Mucinous component.

Features making it urothelial carcinoma (modified Sheldon criteria) - all required:[3]

  1. Located in bladder dome or anterior wall.
  2. Centered on bladder wall (as opposed to the mucosa).
  3. No widespread cystitis cystica/glandularis outside of the bladder dome and anterior wall.
  4. No known urothelial carcinoma elsewhere.

DDx:[4]

Patterns

  • Enteric - looks like colonic adenocarcinoma.
  • Mucinous.
  • Signet ring.

Note:

  • Urachal carcinoma may be nonglandular.[3]

Images

IHC

Features:[5]

  • CK20 +ve.
  • CK7 +ve/-ve.
  • CK34betaE12 +ve/-ve.
  • Beta-catenin -- usu cytoplasmic/membranous +ve.

Others:[6]

  • p63 -ve (+ve in only 3%).

UC versus CRC -- not absolute but useful:

  • CK34betaE12 +ve in UC (-ve in CRC).
  • Beta-catenin -ve nuclei in UC (+ve nuclei in CRC).

Sign out

  • The diagnosis is a clinicopathologic diagnosis - one needs imaging to make it.[4]
  • May be staged with the Sheldon system.[2]

Sheldon staging system

Staging as Sheldon et al.:[7][5]

  • pT1 - confined to urachal mucosa.
  • pT2 - confined to the urachus.
  • pT3a - extension into the bladder wall
  • pT3b - extension into the abdominal wall.
  • pT3c - structures other than the bladder.
  • pT4a - metastasis to regional lymph nodes.
  • pT4b - metastasis to distant sites.

See also

References

  1. Ashley, RA.; Inman, BA.; Sebo, TJ.; Leibovich, BC.; Blute, ML.; Kwon, ED.; Zincke, H. (Aug 2006). "Urachal carcinoma: clinicopathologic features and long-term outcomes of an aggressive malignancy.". Cancer 107 (4): 712-20. doi:10.1002/cncr.22060. PMID 16826585.
  2. 2.0 2.1 Bruins, HM.; Visser, O.; Ploeg, M.; Hulsbergen-van de Kaa, CA.; Kiemeney, LA.; Witjes, JA. (Oct 2012). "The clinical epidemiology of urachal carcinoma: results of a large, population based study.". J Urol 188 (4): 1102-7. doi:10.1016/j.juro.2012.06.020. PMID 22901574.
  3. 3.0 3.1 Paner, GP.; Barkan, GA.; Mehta, V.; Sirintrapun, SJ.; Tsuzuki, T.; Sebo, TJ.; Jimenez, RE. (Mar 2012). "Urachal carcinomas of the nonglandular type: salient features and considerations in pathologic diagnosis.". Am J Surg Pathol 36 (3): 432-42. doi:10.1097/PAS.0b013e31823fe49c. PMID 22301493.
  4. 4.0 4.1 Amin, Mahul B. (2010). Diagnostic Pathology: Genitourinary (1st ed.). Amirsys. pp. 2-143. ISBN 978-1931884280.
  5. 5.0 5.1 Gopalan, A.; Sharp, DS.; Fine, SW.; Tickoo, SK.; Herr, HW.; Reuter, VE.; Olgac, S. (May 2009). "Urachal carcinoma: a clinicopathologic analysis of 24 cases with outcome correlation.". Am J Surg Pathol 33 (5): 659-68. doi:10.1097/PAS.0b013e31819aa4ae. PMID 19252435.
  6. Paner, GP.; McKenney, JK.; Barkan, GA.; Yao, JL.; Frankel, WL.; Sebo, TJ.; Shen, SS.; Jimenez, RE. (Jun 2011). "Immunohistochemical analysis in a morphologic spectrum of urachal epithelial neoplasms: diagnostic implications and pitfalls.". Am J Surg Pathol 35 (6): 787-98. doi:10.1097/PAS.0b013e3182189c11. PMID 21572312.
  7. Sheldon, CA.; Clayman, RV.; Gonzalez, R.; Williams, RD.; Fraley, EE. (Jan 1984). "Malignant urachal lesions.". J Urol 131 (1): 1-8. PMID 6361280.