One of the reasons for this procedure is for a bladder tumor that is present in the dome with clinical suspicion of origin in the urachus. A portion of bladder is attached via urachal tract to the skin and must be resected. The skin is usually a circular excision that has a tubular tract or fibroadipose tissue connecting the bladder and the umbilical skin. Usually the specimen is a circular portion of full thickness bladder wall, and the periphery of the bladder wall is sampled for frozen section margins. The bladder dome is usually the portion of bladder submitted. If there is additional tissue, try to identify the walls and/or look for orientation from surgery.
- Ink the surgical margin of the skin excision. If there is orientation, designate the margins with different colors.
- Ink the surgical margin of the bladder excision. If there is orientation, ink the margins different colors.
- Sections of the umbilical opening into the tubular segment may show the transition of the skin into mucosa, in other cases this connection may be stenosed or obliterated.
- When the tumor is in the lumen, ink the external half one color and the half closer to the bladder another color.
- The description must mention all of the different surfaces.
Usually you get a circular portion of full thickness bladder wall, and surgeons ask for the periphery of the bladder wall to be done as frozen section margins. If they aren't done on frozen, you can shave the peripheral margins or breadloaf the specimen, depending on what works better for that particular case. Then it is important to look in the soft tissue below the bladder wall for the remnant urachus (which may be present as a small cyst or nodule if not as a tube). Extending from the bladder is a long piece of fibroadipose tissue to the umbilical skin, which should contain a fibrosed or obliterated (sometimes it can have a residual small lumen, kind of like a ureter) tube extending from beneath the skin to beneath the bladder. Sample this tube liberally, and also sample the majority of the end of the tube that is closest to the bladder because that is where the cancer would arise from.
If the tumor is close to the skin, you focus on the skin margins and less on the bladder margins. If the urachal tumor is closer to the bladder, then usually you do not have to submit skin margins - one section of the umbilical skin with underlying tissue should suffice.
If a partial cystectomy and urachus is resected, there is a tumor or an ulcer from prior biopsy in the center of the bladder specimen, at which point you should sample the residual ulcer and underlying tissue, paying attention to any nodules or the end of the urachus present there.
Sections for Histology
- Submit shave margins of the skin and make the note to embed them ink side down.
- The sections of the urachal tract should be done on the short axis, showing the lumen as a circle.
- Take sections of the bladder mucosa transitioning to the mucosa of the tubular segment.
- Take any sections of other bladder structures and their margins, if included.
"Bladder tumor, urachus, umbilicus". Received in a medium container is a
3.8 x 3.5 cm circular portion of bladder mucosa and wall with attached fibrous tissue
and adipose tissue. In the center of the portion of mucosa is a 2.0 x 0.5 cm
central ulcer which extends into the underlying soft tissue and approaches the
underlying peritoneum. At the base of the ulcer is a 0.5 cm firm nodule with a cystic center.
Attached to the bladder is a 15.0 x 2.8 x 1.5 cm portion of soft tissue,
partially lined by peritoneum, which connects to a 3.0 x 1.5 cm portion of
umbilical skin with no gross abnormality except for small linear scars. Within
the portion of soft tissue connecting the umbilicus is a 0.3 cm diameter,
round tubular structure with no clear lumen present. This structure, probable
remnant urachus, extends close to the bladder and the underlying cystic nodule.
1A-F. Shave of bladder margins. Frozen section controls (ss)
1G. Sample of ulcer. Frozen section control. (ss)
1H-K. Remaining bladder mucosa and wall.
1L. Peritoneum beneath tumor with urachal remnant/soft tissue nodule.
1M and N. Sections of probable urachal remnant and surrounding tissue.
1O. Umbilical skin. (ss)
Modified February 2009