Bladder Mass in an Older Female

Deloar Hossain, M.D.

Specimen Type:

Bladder

History:

A 50 year old female with bladder mass underwent bladder biopsy.

Pathologic Features:

The surface urothelium is compressed. Under the surface, there are areas with inter-anastomosing cords of cytologically bland urothelium. Peripheral palisading and spindle cell appearance is present within the nests (Fig 1). In other areas, the cells are arranged in broad nests and have mild to moderate cytologic atypia. Mitosis are scnty (Figs 2A and B). Immunostain with CK 20 is negative in areas of the tumor arranged in narrow inter-anastomosing cords (Fig 3A). Other areas of the tumor, arranged in broad nests show strong reactivity with CK20 (Fig 3B), MIB-1 (Fig 3C) and p53 (Fig 3D).

Differential Diagnosis:

  • Inverted urothelial papilloma
  • Cystitis cystica et glandularis
  • Grade 1 (of 3) Papillary urothelial carcinoma, inverted growth pattern

Diagnosis:

Grade 1 (of 3) Papillary urothelial carcinoma, inverted growth pattern

Urothelial carcinoma with an inverted growth pattern tends to show greater degree of cytologic atypia, increased mitoses and grows typically as thick bulbous cords. Inverted papillomas on the other hand grow as narrow anastomosing cords, are cytologically bland and typically lack mitoses. However, endophytic growth in urothelial carcinoma with an inverted pattern may also exist as inter-anastomosing cords and columns of urothelium, with resemblance to inverted papilloma (inverted papilloma-like pattern). In difficult cases, immunostains for CK20, p53 and MIB-1 are helpful in making the distinction.

References:

  1. Jones, TD et al., Urothelial carcinoma with an inverted growth pattern can be distinguished from inverted papilloma by fluorescence in situ hybridization, immunohistochemistry, and morphologic analysis. Am J Surg Pathol. 2007 Dec; 31(12):1861-7.