Pheochromocytoma and paraganglioma characteristically form small nests of uniform polygonal chromaffin cells ("zellballen"). A diagnosis of malignancy can only be made by identifying tumor deposits in tissues that do not normally contain chromaffin cells (e.g., lymph nodes, liver, bone, lung, and other distant metastatic sites).
Regional or distant metastatic disease is documented on initial pathology in only 3% to 8% of patients; thus, an attempt has been made...
There are three ways that cancer spreads in the body.
The three ways that cancer spreads in the body are:
Through tissue. Cancer invades the surrounding normal tissue.
Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.
When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.
The following stages are used for gallbladder cancer:
Stage 0 (Carcinoma in Situ)
In stage 0, abnormalcells are found in the innermost (mucosal) layer of the gallbladder. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.
In stage I, cancer has formed. Stage I is divided into stage IA and stage IB.
Stage IA: Cancer has spread beyond the innermost (mucosal) layer to the connective tissue or to the muscle (muscularis) layer.
Stage IB: Cancer has spread beyond the muscle layer to the connective tissue around the muscle.
Stage II is divided into stage IIA and stage IIB.
Stage IIA: Cancer has spread beyond the visceral peritoneum (tissue that covers the gallbladder) and/or to the liver and/or one nearby organ (such as the stomach, small intestine, colon, pancreas, or bile ducts outside the liver).
Stage IIB: Cancer has spread:
beyond the innermost layer to the connective tissue and to nearby lymph nodes; or
to the muscle layer and nearby lymph nodes; or
beyond the muscle layer to the connective tissue around the muscle and to nearby lymph nodes; or
through the visceral peritoneum (tissue that covers the gallbladder) and/or to the liver and/or to one nearby organ (such as the stomach, small intestine, colon, pancreas, or bile ducts outside the liver), and to nearby lymph nodes.
In stage III, cancer has spread to a main blood vessel in the liver or to nearby organs and may have spread to nearby lymph nodes.
In stage IV, cancer has spread to nearby lymph nodes and/or to organs far away from the gallbladder.