Contributor: Gordon K. Klintworth
Carcinoma arises in many organs and many different subtypes are recognized. The prognosis of the different types varies considerably. The different types of carcinoma include carcinoma-in-situ, squamous carcinoma [carcinoma - squamous cell], adenocarcinoma, adenoid cystic carcinoma, mucoepidermoid carcinoma and neuroendocrine carcinoma. Some are grouped together based on the histologic appearance such as clear cell carcinoma [carcinoma - clear cell], medullary carcinoma [carcinoma - medullary], pigmented carcinoma [carcinoma - pigmented], monomorphic adenocarcinoma [adenocarcinoma - monomorphic] and pleomorphic adenocarcinoma.
Some carcinomas arise from tissues in the vicinity of the eye, including the skin of the eyelid. Such tumors include  basal cell carcinoma [carcinoma - basal cell], sebaceous carcinoma, sweat gland carcinoma [carcinoma - sweat gland]), conjunctiva [carcinoma - conjunctiva], eyelid [carcinoma - eyelid], lacrimal sac [carcinoma - lacrimal sac] and lacrimal gland [carcinoma - lacrimal gland], 
Adenocarcinoma may also arise in the ciliary body [adenocarcinoma - ciliary body]. 
Carcinoma can arise in many organs of the body, including the adrenal gland [carcinoma - adrenal], bladder [carcinoma - bladder], breast [carcinoma - breast], bronchus [carcinoma - bronchus], colon [carcinoma - colon],  endometrium [carcinoma - endometrium], esophagus [carcinoma - esophagus], kidney [carcinoma - kidney], larynx [carcinoma - larynx],  lung [carcinoma - lung], nasopharynx [carcinoma - nasopharynx], ovary [carcinoma - ovary], pancreas [carcinoma - pancreas],  prostate gland [carcinoma - prostate], rectum [carcinoma - rectum], salivary gland [carcinoma - salivary gland], stomach [carcinoma - stomach], trachea [carcinoma - trachea], thyroid gland [carcinoma - thyroid],  uterus [carcinoma - uterus]. Such tumors can metastasize to the eye, orbit eyelid and other distant tissues [carcinoma - metastatic].