bladder adenocarcinoma

The differential diagnosis of bladder adenocarcinoma involves identifying and ruling out other glandular lesions in the urinary bladder, as well as secondary involvement of the bladder by an adenocarcinoma from a different organ.

Primary Malignancies

• Urothelial carcinoma with predominantly glandular features/differentiation: This type of cancer can mimic the appearance of adenocarcinoma and requires careful histological examination to differentiate.
• Urachal adenocarcinoma: A rare type of bladder cancer that arises from the urachal remnant, typically located in the dome of the bladder.

Secondary Malignancies

• Metastatic colonic adenocarcinoma (MCA): This is a common secondary malignancy to consider in the differential diagnosis of bladder adenocarcinoma.
• Other metastatic tumors: Such as those from the stomach, small intestine, or other organs, which can also present with glandular differentiation.

Benign Entities

• Cystitis glandularis: A benign condition characterized by gland-like structures in the bladder lining, which can be mistaken for adenocarcinoma.
• Intestinal metaplasia (IM): A condition where the bladder lining takes on characteristics of intestinal tissue, which can also mimic adenocarcinoma.

Immunohistochemical Markers

• Loss of MMR proteins (MLH1, MSH2, MSH6, and PMS2) can help differentiate between urachal adenocarcinoma and colorectal adenocarcinoma.
• Other immunohistochemical markers, such as CK7, CK20, β-catenin, and thrombomodulin, may also be useful in differentiating primary bladder adenocarcinoma from metastatic colonic adenocarcinoma.

Clinical Relevance

• Accurate diagnosis of bladder adenocarcinoma is crucial to determine the best course of treatment and prognosis.
• A comprehensive clinical workup, including imaging studies and histological examination, is essential to rule out other glandular lesions and secondary involvement of the bladder by an adenocarcinoma from a different organ.

References:

[1] Primary bladder adenocarcinoma usually lacks GATA3 staining, rendering this stain useless in differential diagnosis from secondary colorectal adenocarcinoma [6]. [2] The accurate diagnosis of adenocarcinoma of the urinary bladder can be very challenging, as a wide variety of benign and malignant glandular lesions occur in the urinary bladder. 5,6 [3] Aims: This study evaluates immunohistochemical markers for the differential diagnosis of primary bladder adenocarcinoma (BAC) from secondarily involving colorectal adenocarcinoma (CAC). [15] [4] Useful immunohistochemical antibodies in the differential diagnosis of urachal adenocarcinoma (UrC), colorectal adenocarcinoma (CRC), and primary bladder adenocarcinoma (PBAC). [14] [5] Accurate diagnosis of adenocarcinoma of the urinary bladder is important and challenging. It has to prompt an extensive clinical workup to rule out other glandular lesions in the urinary bladder, especially the possibility of secondary involvement of the bladder by an adenocarcinoma from a different organ. [12] [6] Adenocarcinoma is an uncommon malignancy in the urinary bladder which may arise primarily in the bladder as well as secondarily from a number of other organs. Our aim is to provide updated information on primary and secondary bladder adenocarcinomas, with focus on pathologic features, differential diagnosis, and clinical relevance. [13]