Benign teratoma of the urachus

Urachal carcinoma: The journey so far and the road ahead

Urachal carcinoma, a rare cancer arising from urachus, accounts for about 1% of bladder cancer. The diagnosis at stage I shows about 63% 5-year survival whereas only 8% of the patients at stage IV shows a 5-year survival. Above 90% of urachal carcinomas are adenocarcinomas and most of the urachal carcinoma cases are invasive, showing a high resemblance to adenocarcinoma of various origins, making it hard for a conclusive diagnosis. Even though inconclusive, immunohistochemistry can play a significant role in identifying urachal carcinoma. Most cases show the biomarkers CK20 and CDX2, whereas CK7 and β-catenin are expressed at a lesser frequency. Due to the few cases available, there is a lack of evidence regarding specific markers differentiating urachal carcinoma from colorectal or primary bladder adenocarcinomas. In addition to immunohistochemistry, genomic characterization is emerging to play a role in the classification and treatment of the disease. Urachal carcinoma has been reported to have a molecular level similarity with colorectal malignancies regarding certain gene expressions. The TP53 mutations inactivating the tumor suppressor can probably be explored as a possible target in treating urachal carcinoma. Additionally, certain targets identified in gastric and breast cancer along with anti-HER2 treatment strategies can be explored. Immuno-oncology utilizes immune checkpoint inhibitors for the treatment of MSI-H tumors whereas a combination of tyrosine kinase inhibitors along with immune checkpoint inhibitors are being studied to treat MSI stable tumors. The article is an in-depth overview of urachal carcinoma addressing the current landscape with an emphasis on the future scenario.

Biomarkers in Urachal Cancer and Adenocarcinomas in the Bladder: A Comprehensive Review Supplemented by Own Data

Urachal cancer (UrC) is a rare but aggressive cancer. Due to overlapping histomorphology, discrimination of urachal from primary bladder adenocarcinomas (PBAC) and adenocarcinomas secondarily involving the bladder (particularly colorectal adenocarcinomas, CRC) can be challenging. Therefore, we aimed to give an overview of helpful (immunohistochemical) biomarkers and clinicopathological factors in addition to survival analyses and included institutional data from 12 urachal adenocarcinomas. A PubMed search yielded 319 suitable studies since 1930 in the English literature with 1984 cases of UrC including 1834 adenocarcinomas (92%) and 150 nonadenocarcinomas (8%). UrC was more common in men (63%), showed a median age at diagnosis of 50.8 years and a median tumor size of 6.0 cm. No associations were noted for overall survival and progression-free survival (PFS) and clinicopathological factors beside a favorable PFS in male patients (p = 0.047). The immunohistochemical markers found to be potentially helpful in the differential diagnostic situation are AMACR and CK34βE12 (UrC versus CRC and PBAC), CK7, β-Catenin and CD15 (UrC and PBAC versus CRC), and CEA and GATA3 (UrC and CRC versus PBAC). Serum markers like CEA, CA19-9 and CA125 might additionally be useful in the follow-up and monitoring of UrC.

Paediatric urachal benign teratoma: a case report and review of the literature

Urachal anomalies are most often seen in children, seldom in adults, but are in general considered rare. The estimated incidence is one in 5000-7000 live births and appears twice as common in males. Despite their rarity, they need to be considered by clinicians, as diseases in the urachus can mimic many abdominal and pelvic conditions and constitute an important differential diagnosis to these. Diagnosis can be made by clinical examination and imaging modalities (computed tomography, ultrasonography, magnetic resonance imaging, voiding cystourethrogram), but some are discovered incidentally. Management of symptomatic urachal anomalies is surgery. Histological examination of the specimen should always be performed to rule out malignancy. We report on the first adolescent described in the literature diagnosed with a urachal sinus harboring a benign teratoma. A combination of the two pathologies is by inference an extremely rare condition, which we here report on and we review the relevant literature on this topic.

Angiomatous leiomyoma of the urachus: A rare entity masquerading as extraluminal gastrointestinal stromal tumor

The urachus is a vestigial structure located between the dome of the bladder and the umbilicus, which results from the involution of the allantoic duct and the cloaca. Persistence of an embryonic urachal remnant can cause various problems during childhood and young adulthood. Urachal leiomyoma is a rare entity with very few cases being reported in literature. It can be misdiagnosed and confused with a wide spectrum of intra-abdominal or pelvic disorders. We hereby report a case of angiomatous leiomyoma originating from the urachal remnant in a 45-year-old lady, masquerading as extraluminal gastrointestinal stromal tumor. Understanding the embryological basis of these urachal disorders and their imaging features coupled with histopathological examination is crucial for the correct diagnosis and management. Pathological diagnosis is required to optimize the surgical approach and preclude unnecessary radical surgery.

Radical surgery and IVA-chemotherapeutic regimen to treat embryonal rhabdomyosarcoma of the urachus: case report

Although rhabdomyosarcoma is the most frequent soft tissue tumor in children, there are extremely few reports of this tumor arising from the urachus. The authors describe another case in a 6-year-old female associated with constipation and a painless suprapubic mass. The specimen had the pathological criteria used to define urachal sarcoma (cytological, histological, and immunohistochemical findings) and urachal remnants were not observed. After complete resection of the primary tumor the patient was treated with chemotherapy (ifosfamide, vincristine, and dactinomycin) and remains alive at 4 years' follow-up with no signs of recurrence. Nowadays the management of children with urachal rhabdomyosarcoma usually includes surgery and chemotherapy. Multimodal therapy and surgery are constantly evolving and have significantly improved overall survival of these patients especially in R0 resected patients.

[Dermoid cyst of the urachus: a case report and review of the literature]

The urachus, a normal embryonic remnant of the primitive bladder dome, exists as a fibrous cord in adult. Urachal disorders are not exceptional, and are expression of incomplete regression. Diagnosis is generally ultrasonographic, rarely clinical. We report a case of urachal dermoid cyst revealed by abdominal pain and underline the diagnostic difficulties related to this unusual localization.

Primary yolk sac tumor of the urachus

Pure yolk sac tumor is the most common malignant gonadal tumor of infants and toddlers. However, the majority of extragonadal germ cell tumors in the midline are either seminomas (germinomas) or teratomas, and pure yolk sac tumors account for only a small fraction of these lesions. To date, only 1 primary urachal pure yolk sac tumor has been reported in the literature. We describe another case, occurring in a 7-month-old male infant who presented with a rapidly enlarging intra-abdominal tumor with marked engorgement of the superficial venous plexus around the umbilicus. With periodic follow-up for 3 years following surgical extirpation of the tumor and adjuvant chemotherapy, this patient is still alive without evidence of disease. Notably, the glandular elements predominating in the frozen sections resulted in the initial misdiagnosis of the tumor as a urachal adenocarcinoma, although the entirely resected specimen revealed typical histologic patterns and Schiller-Duval bodies. Immunohistochemistry showed that the tumor cells were diffusely reactive to alpha-fetoprotein, alpha(1)-antitrypsin, and cytokeratin. Tumor cells were negative for p53 protein, but revealed overexpression for MDM2 protein. Flow cytometry demonstrated a diploid DNA content with S-phase being as high as 55.36%. This case emphasizes that pure yolk sac tumor can occur primarily in the remnant of the urachus in young children.