Bladder & urothelial tract

Squamous cell neoplasms

Squamous cell papilloma

Last author update: 12 April 2022
Last staff update: 12 April 2022

Copyright: 2020-2024,, Inc.

PubMed Search: Squamous cell papilloma bladder[TIAB] "last 5 years"[DP]

Harsh Batra, M.B.B.S., D.C.P., D.N.B.
Anil Parwani, M.D., Ph.D., M.B.A.
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Cite this page: Batra H, Parwani A. Squamous cell papilloma. website. Accessed June 16th, 2024.
Definition / general
  • Rare, benign tumor of the urinary bladder showing delicate fibrovascular cores lined by squamous epithelium
Essential features
  • Rare, benign bladder lesion with female predilection
  • Presents with gross hematuria and irritative bladder symptoms
  • Recurrence is rare
  • Not related to condyloma acuminatum
  • Squamous papilloma
ICD coding
  • ICD-O: 8052/0 - squamous cell papilloma, NOS
  • ICD-10: D30.3 - benign neoplasm of bladder
  • Rare, benign urothelial lesion with < 20 cases reported in known literature
  • F > M (6:1) (Cancer 2000;88:1679)
  • Fourth to seventh decade (Cancer 2000;88:1679)
  • Can arise de novo or along with previous urothelial lesions
  • Most cases involve the dome and the lateral and posterior walls of the bladder (Cancer 2000;88:1679)
  • Largely unknown
  • Smoking
  • Occupational exposure to amines
Clinical features
  • Urine cytology is negative for malignant cells
Radiology description
  • Ultrasonography may show thickened bladder wall
Prognostic factors
  • Recurrence is very rare and progression to carcinoma has not been reported (Cancer 2000;88:1679)
Case reports
  • 32 - 82 year old patients with squamous cell papilloma of urinary bladder, including squamous papilloma related to HPV (Cancer 2000;88:1679)
  • 74 year old man with irritative voiding symptoms and exophytic mass found at the mucosa of the floor and the posterior wall of the bladder (Case Rep Pathol 2013;2013:486312)
  • Noninvasive squamous lesions in the urinary bladder; a case series with 5 reported cases of squamous cell papilloma of the urinary bladder (Am J Surg Pathol 2006;30:883)
Clinical images

Images hosted on other servers:
Cystoscopy finding: whitish exophytic lesion

Cystoscopy finding: whitish exophytic lesion

Gross description
  • Small, whitish, polypoid lesion
Microscopic (histologic) description
Microscopic (histologic) images

Contributed by Harsh Batra, M.B.B.S., D.C.P., D.N.B. and Anil Parwani, M.D., Ph.D., M.B.A.
Transverse section of papillae

Transverse section of papillae

Transverse section through a single papilla

Transverse section through a single papilla

Fibrovascular cores

Fibrovascular cores

Positive stains
Molecular / cytogenetics description
Sample pathology report
  • Urinary bladder, lateral wall, transurethral resection of bladder tumor:
    • Squamous papilloma (see comment)
    • Comment: Microscopic examination shows multiple papillae with fibrovascular core lined by keratinized squamous epithelium. No evidence of stromal invasion, atypia or koilocytic changes seen in the biopsy submitted. Clinical correlation with follow up is advised.
Differential diagnosis
  • Condyloma acuminatum:
    • Multiple, extensive lesions
    • External genitalia condyloma or history of immunosuppression
    • Papillary fronds lined by hyperplastic, metaplastic squamous epithelium that may be hyperkeratotic
    • Presence of koilocytes
    • p53 overexpression by IHC
    • HPV DNA present
    • Aneuploid
  • Verrucous carcinoma:
    • Rare variant of squamous cell carcinoma
    • Diffuse, extensive lesions
    • Endophytic growth pattern with broad nests of tumor cells intimately associated with lamina propria or detrusor muscle with minimal stromal reaction
    • Margins of the lesion are pushing
    • Nuclear atypia is minimal to moderate
    • p53 staining is positive
    • HPV DNA negative
  • Keratinizing squamous metaplasia:
    • Nonpolypoid, flat lesion showing thick squamous epithelium with pronounced hyperkeratosis and hypergranulosis
    • Extensive lesions are associated with neoplasia, so it is recommended to report the presence and the extent (focal versus extensive) of keratinizing squamous metaplasia
  • Squamous cell carcinoma:
    • Irregular infiltrating nests or sheets of malignant squamous cells with destructive stromal invasion
    • Presence of keratin pearls, individual cell keratinization or intercellular bridges
    • Often associated with surface keratinizing squamous metaplasia and dysplasia
Board review style question #1
Squamous papilloma of the urinary bladder is which of the following?

  1. Benign lesion
  2. Carcinoma in situ
  3. Malignant
  4. Papillary urothelial neoplasm of unknown malignant potential (PUNLMP)
Board review style answer #1
A. Benign lesion

Comment Here

Reference: Squamous cell papilloma
Board review style question #2

Which of the following histopathological features distinguishes squamous papilloma of the bladder from condyloma acuminatum?

  1. Absence of fibrovascular cores in the papillae
  2. Absence of koilocytes
  3. Presence of invasion into submucosa
  4. Presence of umbrella cells
Board review style answer #2
B. Absence of koilocytes. Squamous papilloma shows absence of koilocytic change, whereas koilocytes are present in condyloma acuminatum.

Comment Here

Reference: Squamous cell papilloma
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