Actinic keratosis occasionally develops into squamous cell carcinoma and is generally removed prophylactically. Actinic keratosis is not associated with development of any of the other skin cancer types listed.

A fibroma is considered a benign fibrous tissue tumor. The other tumor types are all malignant.

Papillary carcinoma is the most common thyroid cancer (60-70% of all thyroid cancers). Follicular carcinoma is the second most common thyroid cancer type (10-20% of cases), followed by medullary thyroid cancer (5%), then anaplastic carcinoma (under 5% of cases).

90% of medulloblastomas are in pediatric patients. It is the tumor type in 14.5% of primary brain malignancies of childhood and adolescence. Glioblastoma is the most common type of brain tumor in adults and accounts for 52% of all primary brain tumors. Meningiomas are also fairly common in adult populations, accounting for 34% of primary brain tumors. Juvenile pilocytic astrocytoma is a brain tumor of childhood but only accounts for 2% of cases.

Hepatocellular carcinoma accounts for approximately 75% of all primary liver cancers.

Cholangiocarcinoma and hepatoblastoma are rare forms of liver cancer, and a teratoma is a tumor that contains normal-appearing tissues from multiple germ layers, which can appear in multiple locations in the body.

Breast, lung, kidney, and prostate cancers make up approximately 80% of metastases to bone. Stomach cancer can metastasize to bone, but it does so only rarely.

Kaposi sarcoma presents with red, purple, brown, or black papular lesions on the extremities, back, face, mouth, and genitalia. It is caused by human herpes virus 8 (HHV8) and is typically seen in immunocompromised patients.

Neither Burkitt lymphoma nor pancreatic cancer typically present with any associated skin lesions, while melanomas tend to be singular lesions.

Small cell carcinoma (also called oat cell cancer) makes up 15% of lung cancers and almost always presents in patients with a history of cigarette smoking.

Adenocarcinoma is the most common type of lung cancer in patients who have never smoked. Mesothelioma is most commonly caused by asbestos exposure, while bronchial carcinoids are often of unknown etiology.

Multiple myeloma, also known as plasma cell myeloma or Kahler's disease, presents with lytic bone lesions, blood count abnormalities, elevated blood calcium, and an abnormal paraprotein antibodies which can cause damage to kidneys.

Osteosarcoma, while located in the bone, tends to present with a mass visible on imaging. Gastric and ovarian cancer are not associated with any changes in bone (unless due to metastasis).

Paget's disease of the breast will often present as itchy, scaling, cracked, red lesions around the nipple. The other conditions mentioned are all forms of breast cancer, but all of them originate in tissues deeper to the breast and will generally present without a visible rash, though some skin changes such as redness or dimpling may occur.