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Journal of Cancer Research and Therapeutics, Vol. 7, No. 2, April-June, 2011, pp. 223-225 Case Report Urachal papillary cystadenocarcinoma: A rare case report Kavita Mardi, Neelam Gupta Department of Pathology, Indira Gandhi Medical College, Shimla, Himachal Pradesh, India Code Number: cr11056 PMID: 21768722 Abstract Urachal papillary mucinous cystadenocarcinoma is a rare tumor and represents 0.17-0.34% of all bladder tumors. It has an insidious course and variable clinical presentation. We present a case report of a 37-year-old female who presented with a lump in the abdomen. MRI revealed a solidcystic mass in the right lumbar region. Fine needle aspiration cytology was suggestive of adenocarcinoma. Histopathological examination of the excised mass revealed papillary adenocarcinoma that brought out the presence of focal PAS-positive intracytoplasmic mucin in the tumor cells. Clinicians should have a high degree of suspicion for these rare tumors. Keywords: Papillary adenocarcinoma, urachal remnants, urinary bladder Introduction The urachus is a vestigial structure that connects the bladder to the allantois during early embryonic development. It remains patent in a small proportion of adults and becomes clinically important when only complicated by infection, cystic dilation, or when neoplasia develops in it. Urachal adenocarcinomas are extremely rare and their accurate preoperative diagnosis needs a high degree of clinical suspicion and correlation with the radiological findings. We herein report a case of papillary cystadenocarcinoma arising from the urachal tract in a 37-year-old female, to increase awareness regarding this rare entity. Case Report A 37-year-old female presented with complaints of a lump in the abdomen since 1 month. On examination, a firm-to-hard, immobile lump in the right lumbar region measuring 5 × 5 cm was found. Postcontrast MRI revealed a cystic mass with a solid component in the right lumbar region. The cystic mass showed enhancement of the wall and the solid part [Figure - 1]. On fine needle aspiration (FNA) of this lump, the fluid was aspirated and smears prepared from the sediment revealed papillary fragments of tumor cells with a hyperchromatic nucleus, variably prominent nucleoli, and moderate amounts of basophilic cytoplasm. Serum CA-125 levels were also within normal limits. The patient underwent exploratory laparotomy. Peroperatively, a well-circumscribed and irregular mass measuring 6 × 5 cm originated from the urachal tract which was extending up to the dome of the bladder. The mass was excised. On gross examination, a fat-laden soft tissue mass measuring 7 × 6 × 5 cm was revealed. The cut Surface of the mass was partly solid and partly cystic. The solid portion was revealing papillary excrescences [Figure - 2]. The cystic portion was thick walled with variably sized solid nodules and focal papillary excrescences on the inner surface. Microscopic examination revealed pleomorphic tumor cells arranged in papillae, acini, labrynthine pattern, and solid sheets, separated by thick fibrous septae. These pleomorphic tumor cells showed a vesicular to hyperchromatic nucleus with prominent eosinophilic nucleoli [Figure - 3] and [Figure - 4]. Numerous bizarre mitotic figures were seen. In addition, there were extensive areas of hemorrhage and necrosis. The PAS stain revealed focal intracytoplasmic mucin in some of the tumor cells. The diagnosis of papillary mucinous cystadenocarcinoma arising from the patent urachus was rendered. Discussion The urachus is the embryologic remnant of allantois and the adjoining ventral cloaca. It is a tubular structure and its lumen becomes obliterated with the advancing age. However, in a small proportion of adults (2%), its patency with the urinary bladder persists. [1] In such instances, urachus runs downward in the extraperitoneal space from the umbilicus to the apex of the bladder. Histologically, urachal remnants consist of tubular structures and canals, usually lined the by transitional type epithelium. The lumen of the lower part of the persistent urachus may communicate with the cavity of the bladder. Persistent urachal remnants are more likely a normal phenomenon and become clinically important when complicated by infection, cystic dilation, or when neoplasia develops in them. [2],[3],[4],[5] Focal mucinous glandular metaplasia is often seen and may provide a morphological basis for the development of intestinal type tumors. [2] Primary urachal adenocarcinoma is a rare and a devastating disease, representing 0.17-0.34% of all bladder tumors [6] and theoretically might occur at any point up to the umbilicus. Carcinomas arising in the urachus or urachal remnants are generally adenocarcinomas, although occasionally, they can have squamous and transitional cell features. Urachal adenocarcinomas are mostly well-differentiated mucinous adenocarcinomas. The next most frequent pattern is the enteric type; these tumors closely resemble colonic adenocarcinomas and must be distinguished from colonic adenocarcinomas involving the bladder. Rarely, urachal adenocarcinomas can have a signet ring pattern. [7],[8],[9] Immunohistochemically, these tumors are positive for CK20 and can show variable positivity for CK7 and 34BE12. [10] Immunostains do not unequivocally discriminate a urachal from a colorectal carcinoma, but diffuse positivity for 34BE12 would support, and diffuse nuclear immunoreactivity for β-catenin would militate against, a diagnosis of urachal carcinoma. [10] These relatively rare genitourinary neoplasms usually present as a supravesical mass. Most cases occur in individuals in their 40s and 50s, with a mean age of occurrence approximately 10 years younger than that for carcinoma arising in the urothelium. The identification of adenocarcinomas of urachal origin is based on several clinical and pathologic features, the most important of which are location of the tumor in the bladder dome, location centered in the muscular wall rather than in the mucosa, and the absence of intestinal metaplasia or CIS on the urothelium surface. Also helpful is the identification of urachal remnants, a sharp demarcation between tumor and normal urothelium, and the exclusion of metastatic adenocarcinoma from other sites. The pathologic stage is an important prognostic factor in urachal carcinoma. Urothelial surface involvement by the carcinoma and the presence of cystitis cystica/glandularis do not necessarily exclude the diagnosis of urachal carcinomas. Urachal carcinomas commonly occur in the bladder dome and are generally treated by partial cystectomy with an en bloc resection of the median umbilical ligament and umbilicus. Local recurrence may be seen owing to seeding within the distal urothelial tract, particularly in tumors with a polypoid configuration that open into the bladder cavity. Prognosis does not appear to be significantly influenced by histology and grade of the tumor. Metastatic disease has a poor response to chemotherapy. Some tumors may respond to cisplatin-based regimens. The overall survival for all stages is 62 months with 34% of the patients showing survival after 5 years. The type of surgery performed may have an effect on local recurrence despite negative margins of resection. [10] To conclude, misdiagnosis of urachal carcinoma is still a reality. Accurate diagnosis necessitates a high degree of clinical suspicion and imaging studies. Appropriate local treatment is the key for improved survival. References
Copyright 2011 - Journal of Cancer Research and Therapeutics The following images related to this document are available:Photo images[cr11056f2.jpg] [cr11056f3.jpg] [cr11056f1.jpg] [cr11056f4.jpg] |
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