The 1973 WHO grading system for TCCs (papilloma, G1, G2 or G3) is most commonly used despite being superseded by the 2004 WHO grading (papillary neoplasm of low malignant potential [PNLMP], low grade, and high grade papillary carcinoma).

Diagnostic tests typically include complete blood tests, urinalysis, urine culture, X-rays of the abdomen and chest, and bladder imaging. The definitive diagnosis of bladder cancer will require a tissue biopsy and subsequent examination of the cells under the microscope.

Diagnosis may include a fluorescence in situ hybridization (FISH) test, computed tomography urography (CTU), magnetic resonance urography (MRU), intravenous pyelography (IVP) x-ray, ureteroscopy, or biopsy.

Because most bladder cancers are invasive into the bladder wall, surgical removal is usually not possible. The majority of transitional cell carcinomas are treated with either traditional chemotherapy or nonsteroidal anti-inflammatory drugs.

The diagnosis of urachal cancer can be difficult and usually requires a multidisciplinary approach. A calcification in the midline can be detected in some patients in abdominal imaging studies. A cystoscopy is helpful in most cases. For diagnosis evaluation of a tissue biopsy is needed, which is usually obtained by transurethral resection (TURBT). Measurement of serum concentrations of CEA, CA19-9 and CA125 can be helpful in monitoring urachal cancer

Cystoscopy, a procedure in which a flexible tube bearing a camera and various instruments is introduced into the bladder through the urethra allows diagnosis and by biopsying suspicious lesions.

The gold standard for diagnosing bladder cancer is biopsy obtained during cystoscopy. Urine cytology can be obtained in voided urine or at the time of the cystoscopy ("bladder washing"). Cytology is not very sensitive (a negative result cannot reliably exclude bladder cancer). There are newer non-invasive urine bound markers available as aids in the diagnosis of bladder cancer, including human complement factor H-related protein, high-molecular-weight carcinoembryonic antigen, and nuclear matrix protein 22 (NMP22). NMP22 is also available as a prescription home test. Other non-invasive urine based tests include the CertNDx Bladder Cancer Assay, which combines FGFR3 mutation detection with protein and DNA methylation markers to detect cancers across stage and grade, UroVysion, and Cxbladder.

The diagnosis of bladder cancer can also be done with a Hexvix/Cysview guided fluorescence cystoscopy (blue light cystoscopy, Photodynamic diagnosis), as an adjunct to conventional white-light cystoscopy. This procedure improves the detection of bladder cancer and reduces the rate of early tumor recurrence, compared with white light cystoscopy alone. Cysview cystoscopy detects more cancer and reduces recurrence. Cysview is marketed in Europe under the brand name Hexvix

However, visual detection in any form listed above, is not sufficient for establishing pathological classification, cell type or the stage of the present tumor. A so-called cold cup biopsy during an ordinary cystoscopy (rigid or flexible) will not be sufficient for pathological staging either. Hence, a visual detection needs to be followed by transurethral surgery. The procedure is called transurethral resection of bladder tumor (TURBT). Further, bimanual examination should be carried out before and after the TURBT to assess whether there is a palpable mass or if the tumour is fixed ("tethered") to the pelvic wall. The pathological classification obtained by the TURBT-procedure, is of fundamental importance for making the appropriate choice of ensuing treatment and/or follow-up routines.

As of 2010 there is insufficient evidence to determine if screening for bladder cancer in people without symptoms is effective or not.

In 2013 a preliminary, small study of 98 samples of urine, all from men—24 who had cancer, and 74 with bladder-related problems but no cancer yet used a gas chromatograph to successfully examine the vapor from heated urine samples to identify cancer.

Transitional refers to the histological subtype of the cancerous cells as seen under a microscope.

Urachal cancer usually is an adenocarcinoma (about 90%) mostly with mucinous/colloidal histology. The histology can be difficult to distinguish especially from colorectal cancer and primary adenocarcinoma of the urinary bladder. Immunohistochemistry in this situation is of little help with stains for betaCatenin and Cytokeratin 7 can be helpful. Other rare types include urothelial carcinoma, squamous cell carcinoma, neuroendocrine carcinoma and sarcoma.

Diagnostic systems in use are the Sheldon system based on proposals from Wheeler and Hill and Mostofi. Recent diagnostic classification schemes have been proposed by Herr et al and Gopalan et al. For non-adenocarcinoma urachal cancer a diagnostic classification scheme has been proposed by Paner et al.

Diagnosis is established by transurethral biopsy. Types of urethral cancer include transitional cell carcinoma, squamous cell carcinoma, adenocarcinoma, and melanoma.

Prognosis is highly variable and dependent upon a multitude of factors. Reoccurrence does occur. Treatment is determined on a case-by-case basis.

Large-cell carcinoma (LCC), like small-cell carcinoma (SCC) is very rare and only accounts for about 5% of all cervical cancers. Early-stage LCC are extremely aggressive and difficult to diagnose due to the sub-mucosal location of the tumor and intact overlying mucosa. As with SCC, in LCC early cases are asymptomatic. Later stages present with irregular bleeding, vaginal spotting, discharge, and pelvic pain. The basis for treatment of LCC tumors is derived from therapy used for SCC; when diagnosed, multimodal therapy should be considered just as with SCC.

Cancer screening uses medical tests to detect disease in large groups of people who have no symptoms. For individuals with high risk of developing lung cancer, computed tomography (CT) screening can detect cancer and give a person options to respond to it in a way that prolongs life. This form of screening reduces the chance of death from lung cancer by an absolute amount of 0.3% (relative amount of 20%). High risk people are those age 55–74 who have smoked equivalent amount of a pack of cigarettes daily for 30 years including time within the past 15 years.

CT screening is associated with a high rate of falsely positive tests which may result in unneeded treatment. For each true positive scan there are about 19 falsely positives scans. Other concerns include radiation exposure and the cost of testing along with follow up. Research has not found two other available tests—sputum cytology or chest radiograph (CXR) screening tests—to have any benefit.

The United States Preventive Services Task Force (USPSTF) recommends yearly screening using low-dose computed tomography in those who have a total smoking history of 30 pack-years and are between 55 and 80 years old until a person has not been smoking for more than 15 years. Screening should not be done in those with other health problems that would make treatment of lung cancer if found not an option. The English National Health Service was in 2014 re-examining the evidence for screening.

These aggressive tumors are generally diagnosed at advanced stages and survival is generally shorter. The prognosis of SRCC and its chemosensitivity with specific regimens are still controversial as SRCC is not specifically identified in most studies and its poor prognosis may be due to its more advanced stage. One study suggests that its dismal prognosis seems to be caused by its intrinsic tumor biology, suggesting an area for further research.

Treatment methods include surgery, chemotherapy, radiation therapy and medication.

Primary signet-ring cell carcinoma of the urinary bladder is extremely rare and patient survival is very poor and occurs mainly in men ages 38 to 83. However, one such patient treated with a radical cystectomy followed by combined S-1 and Cisplatin adjuvant chemotherapy did demonstrate promising long-term survival of 90 months.

HGPIN is diagnosed from tissue by a pathologist, which may come from:

- a needle biopsy taken via the rectum and,

- surgical removal of prostate tissue:

- transurethral resection of the prostate - removal of extra prostate tissue to improve urination (a treatment for benign prostatic hyperplasia),

- radical prostatectomy - complete removal of prostate and seminal vesicles (a treatment for prostate cancer).

Blood tests for prostate specific antigen (PSA), digital rectal examination, ultrasound scanning of the prostate via the rectum, fine needle aspiration or medical imaging studies (such as magnetic resonance imaging) are "not" useful for diagnosing HGPIN.

Several tests are used to diagnose vaginal cancer, including:

- Physical exam and history

- Pelvic exam

- Pap smear

- Biopsy

- Colposcopy

Recommendations for women with vaginal cancer is not to have routine surveillance imaging to monitor the cancer unless they have new symptoms or rising tumor markers. Imaging without these indications is discouraged because it is unlikely to detect a recurrence or improve survival, and because it has its own costs and side effects. MRI provides visualization of the extent of vaginal cancer.

Prevention

Definitive diagnosis of Merkel cell carcinoma (MCC) requires examination of biopsy tissue. An ideal biopsy specimen is either a punch biopsy or a full-thickness incisional biopsy of the skin including full-thickness dermis and subcutaneous fat. In addition to standard examination under light microscopy, immunohistochemistry (IHC) is also generally required to differentiate MCC from other morphologically similar tumors such as small cell lung cancer, the small cell variant of melanoma, various cutaneous leukemic/lymphoid neoplasms, and Ewing's sarcoma. Similarly, most experts recommend longitudinal imaging of the chest, typically a CT scan, to rule out that the possibility that the skin lesion is a cutaneous metastasis of an underlying small cell carcinoma of the lung.

It has been observed that HPV18 is the most prevalent type in Small cell cervical cancer.

Like other types of cervical cancer it seems to be associated with high-risk (e.g. 16, 18, 31) HPV Infection.

HGPIN in isolation does not require treatment. In prostate biopsies it is not predictive of prostate cancer in one year if the prostate was well-sampled, i.e. if there were 8 or more cores.

The exact timing of repeat biopsies remains an area of controversy, as the time required for, and probability of HGPIN transformations to prostate cancer are not well understood.

For surface epithelial-stromal tumors, the most common sites of metastasis are the pleural cavity (33%), the liver (26%), and the lungs (3%).

Prognosis of the CC is affected by age, stage, and histology as well as treatment

The primary treatment is surgical. FIGO-cancer staging is done at the time of surgery which consists of peritoneal cytology, total hysterectomy, bilateral salpingo-oophorectomy, pelvic/para-aortic lymphadenectomy, and omentectomy. The tumor is aggressive and spreads quickly into the myometrium and the lymphatic system. Thus even in presumed early stages, lymphadenectomy and omentectomy should be included in the surgical approach. If the tumor has spread surgery is cytoreductive followed by radiation therapy and/or chemotherapy.

The five years survival was reported to be 68%.

The U.S. Preventive Services Task Force (USPSTF) issues recommendations for various cancers:

- Strongly recommends cervical cancer screening in women who are sexually active and have a cervix at least until the age of 65.

- Recommend that Americans be screened for colorectal cancer via fecal occult blood testing, sigmoidoscopy, or colonoscopy starting at age 50 until age 75.

- Evidence is insufficient to recommend for or against screening for skin cancer, oral cancer, lung cancer, or prostate cancer in men under 75.

- Routine screening is not recommended for bladder cancer, testicular cancer, ovarian cancer, pancreatic cancer, or prostate cancer.

- Recommends mammography for breast cancer screening every two years from ages 50–74, but does not recommend either breast self-examination or clinical breast examination. A 2013 Cochrane review concluded that breast cancer screening by mammography had no effect in reducing mortality because of overdiagnosis and overtreatment.

Screens for gastric cancer using photofluorography due to the high incidence there.