The 1973 WHO grading system for TCCs (papilloma, G1, G2 or G3) is most commonly used despite being superseded by the 2004 WHO grading (papillary neoplasm of low malignant potential [PNLMP], low grade, and high grade papillary carcinoma).

The criteria for diagnosing BACs have changed since 1999. Under the new definition, BAC is defined as a tumor that grows in a lepidic (that is, a scaly covering) fashion along pre-existing airway structures, without detectable invasion or destruction of the underlying tissue, blood vessels, or lymphatics. Because invasion must be ruled out, BAC can be diagnosed only after complete sectioning and examination of the entire tumor, not using biopsy or cytology samples. BAC is considered a pre-invasive malignant lesion that, after further mutation and progression, eventually generates an invasive adenocarcinoma. Therefore, it is considered a form of carcinoma "in situ" (CIS).

The risk of renal cell carcinoma can be reduced by maintaining a normal body weight.

PUNLMPs are exophytic lesions that appear friable to the naked eye and when imaged during cystoscopy.

They are definitively diagnosed after removal by microscopic examination by pathologists.

Histologically, they have a papillary architecture with slender fibrovascular cores and rare basal mitoses. The papillae rarely fuse and uncommonly branch. Cytologically, they have uniform nuclear enlargement.

They cannot be reliably differentiated from low grade papillary urothelial carcinomas using cytology, and their diagnosis (vis-a-vis low grade papillary urothelial carcinoma) has a poor inter-rater reliability.

Pathologic grading and staging tumors are:

graded by the degree of cellular atypia (G1->G3), and

staged:

Magnetic Resonance Imaging (MRI) scans provide an image of the soft tissues in the body using radio waves and strong magnets. MRI can be used instead of CT if the patient exhibits an allergy to the contrast media administered for the test. Sometimes prior to the MRI scan, an intravenous injection of a contrasting material called gadolinium is given to allow for a more detailed image. Patients on dialysis or those who have renal insufficiency should avoid this contrasting material as it may induce a rare, yet severe, side effect known as nephrogenic systemic fibrosis. A bone scan or brain imaging is not routinely performed unless signs or symptoms suggest potential metastatic involvement of these areas.

MRI scans should also be considered to evaluate tumour extension which has grown in major blood vessels, including the vena cava, in the abdomen. MRI can be used to observe the possible spread of cancer to the brain or spinal cord should the patient present symptoms that suggest this might be the case.

80% of cases in the United States are diagnosed by mammography screening.

PUNLMPs are treated like non-invasive low grade papillary urothelial carcinomas, excision and regular follow-up cystoscopies.

There is a rare occurrence of a pelvic recurrence of a low-grade superficial TCC after cystectomy. Delayed presentation with recurrent low-grade urothelial carcinoma is an unusual entity and potential mechanism of traumatic implantation should be considered. Characteristically low-grade tumors are resistant to systemic chemotherapy and curative-intent surgical resection of the tumor should be considered.

While the histopathologic features and molecular features of ADH are that of (low-grade) DCIS, its clinical behaviour, unlike low-grade DCIS, is substantially better; thus, the more aggressive treatment for DCIS is not justified. In oncology in general, it is observed that tumour size is often strongly predictive of the clinical behaviour and, thus, a number of cancers (e.g. adenocarcinoma of the lung, papillary renal cell carcinoma) are defined, in part, on the basis of a minimum size.

As metanephric adenomas are considered benign, they can be left in place, i.e. no treatment is needed.

According to the NIH Consensus Conference , if DCIS is allowed to go untreated, the natural course or natural history varies according to the grade of the DCIS. Unless treated, approximately 60 percent of low-grade DCIS lesions will have become invasive at 40 years follow-up. High-grade DCIS lesions that have been inadequately resected and not given radiotherapy have a 50 percent risk of becoming invasive breast cancer within seven years. Approximately half of low-grade DCIS detected at screening will represent overdiagnosis, but overdiagnosis of high-grade DCIS is rare. The natural history of intermediate-grade DCIS is difficult to predict. Approximately one-third of malignant calcification clusters detected at screening mammography already have an invasive focus.

The prognosis of IDC depends, in part, on its histological subtype. Mucinous, papillary, cribriform, and tubular carcinomas have longer survival, and lower recurrence rates. The prognosis of the most common form of IDC, called "IDC Not Otherwise Specified", is intermediate. Finally, some rare forms of breast cancer (e.g., sarcomatoid carcinoma, inflammatory carcinoma) have a poor prognosis. Regardless of the histological subtype, the prognosis of IDC depends also on tumor size, presence of cancer in the lymph nodes, histological grade, presence of cancer in small vessels (vascular invasion), expression of hormone receptors and of oncogenes like HER2/neu.

These parameters can be entered into models that provide a statistical probability of systemic spread. The probability of systemic spread is a key factor in determining whether radiation and chemotherapy are worthwhile. The individual parameters are important also because they can predict how well a cancer will respond to specific chemotherapy agents.

Overall, the 5-year survival rate of invasive ductal carcinoma was approximately 85% in 2003.

It is diagnosed based on tissue, e.g. a biopsy. Histomorphologically, it has architectural changes seen in low-grade ductal carcinoma in situ (DCIS), e.g. cribriform architecture, and like low-grade DCIS has minimal nuclear atypia and no necrosis.

Prognosis and treatment is the same as for the most common type of ovarian cancer, which is epithelial ovarian cancer.

The median survival of primary peritoneal carcinomas is usually shorter by 2–6 months time when compared with serous ovarian cancer. Studies show median survival varies between 11.3–17.8 months. One study reported 19-40 month median survival (95% CI) with a 5-year survival of 26.5%.

Elevated albumin levels have been associated with a more favorable prognosis.

Intraductal papillary mucinous neoplasms can come to clinical attention in a variety of different ways. The most common symptoms include abdominal pain, nausea and vomiting. The most common signs patients have when they come to medical attention include jaundice (a yellowing of the skin and eyes caused by obstruction of the bile duct), weight loss, and acute pancreatitis. These signs and symptoms are not specific for an intraductal papillary mucinous neoplasm, making it more difficult to establish a diagnosis. Doctors will therefore often order additional tests.

Once a doctor has reason to believe that a patient may have an intraductal papillary mucinous neoplasm, he or she can confirm that suspicion using one of a number of imaging techniques. These include computerized tomography (CT), endoscopic ultrasound (EUS), and magnetic resonance cholangiopancreatography (MRCP). These tests will reveal dilatation of the pancreatic duct or one of the branches of the pancreatic duct. In some cases a fine needle aspiration (FNA) biopsy can be obtained to confirm the diagnosis. Fine needle aspiration biopsy can be performed through an endoscope at the time of endoscopic ultrasound, or it can be performed through the skin using a needle guided by ultrasound or CT scanning.

IPMN forms cysts (small cavities or spaces) in the pancreas. These cysts are visible in CT scans (X-ray computed tomography). However, many pancreatic cysts are benign (see Pancreatic disease).

A growing number of patients are now being diagnosed before they develop symptoms (asymptomatic patients). In these cases, the lesion in the pancreas is discovered accidentally (by chance) when the patient is being scanned (i.e. undergoing an ultrasound, CT or MRI scan) for another reason. Up to 6% of patients undergoing pancreatic resection did so for treatment of incidental IPMNs.

In 2011, scientists at Johns Hopkins reported that they have developed a gene-based test that can be used to distinguish harmless from precancerous pancreatic cysts. The test may eventually help patients with harmless cysts avoid needless surgery. Bert Vogelstein and his colleagues discovered that almost all of the precancerous cysts (intraductal papillary mucinous neoplasms) of the pancreas have mutations in the KRAS and/or the GNAS gene. The researchers then tested a total of 132 intraductal papillary mucinous neoplasms for mutations in KRAS and GNAS. Nearly all (127) had mutations in GNAS, KRAS or both. Next, the investigators tested harmless cysts such as serous cystadenomas, and the harmless cysts did not have GNAS or KRAS mutations. Larger numbers of patients must be studied before the gene-based test can be widely offered.

a) Surgical resection is mainstay of treatment, whenever possible. If tumor is completely removed, post-operative radiation therapy is typically not needed since acinic cell is considered a low-grade histology. Post-operative radiation therapy for acinic cell carcinoma is used if: 1) margins are positive, 2) incomplete resection, 3) tumor invades beyond gland, 4) positive lymph nodes.

b) Neutron beam radiation

c) Conventional radiation

d) Chemotherapy

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

The criteria for diagnosing BAC have changed since 1999. Under the new definition, BAC is not considered to be an invasive tumor by pathologists, but as one form of carcinoma in situ (CIS). Like other forms of CIS, BAC may progress and become overtly invasive, exhibiting malignant, often lethal, behavior. Major surgery, either a lobectomy or a pneumonectomy, is usually needed to control it, and like other forms of non-small cell lung carcinoma, recurrences are frequent. Therefore, oncologists classify it among the other malignant tumors, which are invasive tumors.

Under the new, more restrictive WHO criteria for lung cancer classification, BAC is now diagnosed much less frequently than it was in the past. Recent studies suggest that BAC comprises between 3% and 5% of all lung carcinomas in the U.S.

Prognosis is good for acinic cell carcinoma of the parotid gland, with five-year survival rates approaching is 90%, and 20-year survival exceeding 50%. Patients with acinic cell carcinomas with high grade transformation (sometimes also called dedifferentiation) have significantly worse survival.

The prognosis of an acinic cell carcinoma originating in the lung is much more guarded than cases of this rare histotype occurring in most other organs, but is still considerably better than for other types of lung cancer.

MTSCC can be a difficult diagnosis due to its morphologic heterogeneity. Several morphological variants have been described, as the ‘‘mucin-poor variants’’, showing a predominance of tubular or spindle cell components and only minimal pale mucinous background.

Focal papillations or papillary cores and foamy histiocytes can also be seen, creating confusion with type 1 papillary RCC. Helpful features for diagnosis are bland cytologic features and adjacent tubular and spindle cell components. Focal areas of clear cells and oncocytic cells can also be present.

Metanephric adenoma is diagnosed histologically. The tumours can be located at upper pole, lower pole and mid-hilar region of the kidney; they are well circumscribed but unencapsulated, tan pink, with possible cystic and hemorrhagic foci. They show a uniform architecture of closely packed acinar or tubular structures of mature and bland appearance with scanty interposed stroma. Cells are small with dark staining nuclei and inconspicuous nucleoli. Blastema is absent whereas calcospherites may be present. Glomeruloid figures are a striking finding, reminiscent of early fetal metenephric tissue. The lumen of the acini may contain otherwise epithelial infoldings or fibrillary material but it is quite often empty. Mitoses are conspicuously absent.

In the series reported by Jones "et al." tumour cells were reactive for Leu7 in 3 cases of 5, to vimentine in 4 of 6, to cytocheratin in 2 of 6, to epithelial membrane antigen in 1 of 6 cases and muscle specific antigen in 1 of 6.

Olgac "et al." found that intense and diffuse immunoreactivity for alpha-methylacyl-CoA racemase (AMACR) is useful in differentiating renal cell carcinoma from MA but a panel including AMACR, CK7 and CD57 is better in this differential diagnosis.

Differential diagnosis may be quite difficult indeed as exemplified by the three malignancies initially diagnosed as MA that later metastasized, in the report by Pins et al.

The diagnosis is based on tissue examination, e.g. biopsy.

The name of the lesion describes it microscopic appearance. It has nipple-like structures with fibrovascular cores () that are long in relation to their width (villus-like), which are covered with a glandular pseudostratified columnar epithelium.

Tumor size staging and node involvement staging can be combined into a single clinical staging number.

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

Carcinoma "in situ" is, by definition, a localized phenomenon, with no potential for metastasis unless it progresses into cancer. Therefore, its removal eliminates the risk of subsequent progression into a life-threatening condition.

Some forms of CIS (e.g., colon polyps and polypoid tumours of the bladder) can be removed using an endoscope, without conventional surgical resection. Dysplasia of the uterine cervix is removed by excision (cutting it out) or by burning with a laser. Bowen's disease of the skin is removed by excision. Other forms require major surgery, the best known being intraductal carcinoma of the breast (also treated with radiotherapy). One of the most dangerous forms of CIS is the "pneumonic form" of BAC of the lung, which can require extensive surgical removal of large parts of the lung. When too large, it often cannot be completely removed, with eventual disease progression and death of the patient.

Because DCIS is normally found early and it is treated or managed, it is difficult to say what occurs if left untreated. About 2% of women who are diagnosed with this condition and treated died within 10 years. Biomarkers can identify which women who were initially diagnosed with DCIS are at high or low risk of subsequent invasive cancer.

Papillary renal cell carcinoma: MTSCC may have some morphologic similarities to the more common papillary renal cell carcinoma (papillary RCC), particularly the basophilic tumors (type 1 papillary RCC) with prominent solid growth pattern with sarcomatoid transformation.