Urachus

Images
Infected urachal remnants: an unusual presentation https://twitter.com/BJR_Radiology/status/789177618293809152
Mixed urachal/omphalomesenteric rests https://twitter.com/mreyesm/status/727507963523510272
See also
omphalomesenteric duct remants

Urachal leiomyoma is a rare entity with very few cases being reported in literature.
Open References
Angiomatous leiomyoma of the urachus: A rare entity masquerading as extraluminal gastrointestinal stromal tumor.
Anand M, Deshmukh SD, Gulati HK, Ladkat SS, Jadhav SE, Purandare SN.
Urol Ann. 2013 Jul;5(3):200-3. doi:10.4103/0974-7796.115752.
PMID: #24049386 # Free
Paywall references
Urachal myoma: a case report.
Ding DC, Yu MH, Wu CC, Liu JY.
Acta Obstet Gynecol Scand. 2003 (...)

Examples
urachal carcinomas urachal adenocarcinoma

Urachal carcinomas occur mostly in the bladder dome, comprising 22% to 35% of vesical adenocarcinomas, and are generally treated by partial cystectomy with en bloc resection of the median umbilical ligament and umbilicus. Detailed pathologic studies with clinical outcome correlation are few.
Pathologic stage is an important prognostic factor in urachal carcinoma. Surface urothelial involvement by carcinoma and presence of cystitis cystica/glandularis do not necessarily exclude the (...)

congenital patent urachus, persistant urachus
Definition: Congenital patent urachus is an extremely rare condition with an incidence of 1-2.5:100’000 deliveries. Males are affected twice as often as females.
Images
8yo m with persist. urachus. There R 2 other wet umbilicus rests: allantoid & omphalomesenteric
https://twitter.com/mreyesm/status/717690105247494144
On prenatal US, the presence of a direct communication between the fetal bladder and the umbilical cord cyst confirms (...)

PO
Definition : A urachal cyst is a collection of tissue and fluid between the bladder and the belly button (umbilicus). The cyst forms in the remnants of the urachus, a structure normally present in a fetus that usually closes up before birth.
Synopsis
cystic structures lined by benign urothelium and cuboidal epithelium expressing GATA3.
lobulated cystic structure lined by benign epithelium
Images
Infected Urachal Cyst https://twitter.com/NEJM/status/816376204987080704
See (...)

See also
urachal anomalies urachal fistula urachal sinus urachal cyst vesical diverticulum ( bladder diverticulum )