Adrenal gland- Adrenocortical adenoma showing weak to moderate PR immunostaining in the majority of tumor cells.

Adrenal gland- Adrenocortical carcinoma with weak PR immunostaining of a fraction of tumor cells.

Adrenal gland- PR negative pheochromocytoma.

Breast- Invasive breast cancer of no special type (NST) with strong PR immunostaining of tumor cells.

Breast- Invasive lobular breast cancer with strong PR immunostaining of tumor cells.

Colon- PR negative colorectal adenocarcinoma.

Kidney- PR negative clear cell renal cell carcinoma.

Liver- PR negative hepatocellular carcinoma.

Lung- PR negative small cell carcinoma.

Lymph node- PR negative diffuse large B-cell lymphoma.

Lymph node- PR negative Hodgkin’s lymphoma.

Ovary- Endometroid carcinoma with strong PR immunostaining of tumor cells.

Ovary- Granulosa cell tumor with weak to moderate PR immunostaining of a majoritiy of tumor cells.

Ovary- PR negative Brenner tumor.

Ovary- Serous high-grade carcinoma with strong PR immunostaining in most tumor cells.

Pancreas- Neuroendocrine tumor with strong PR immunostaining of all tumor cells.

Pancreas- PR negative ductal adenocarcinoma.

Pancreas- PR negative neuroendocrine tumor.

Penis- PR negative squamous cell carcinoma.

Pharynx- PR negative squamous cell carcinoma.

Prostate- PR negative adenocarcinoma (Gleason 3+3=6). Some stroma cells show PR positivity, however.

Prostate- Small cell carcinoma with weak to moderate PR immunostaining of few scattered tumor cells.

Salivary gland- PR negative Warthin tumor.

Skin- PR negative Merkel cell carcinoma.

Soft tissue- PR negative granular cell tumor.

Soft tissue- PR negative liposarcoma.

Stomach- PR negative gastric adenocarcinoma.

Stomach- PR negative gastrointestinal stromal tumor (GIST).

Testis- Leydig cell tumor containing scattered tumor cells showing moderate to strong PR immunostaining.

Testis- PR negative seminoma.

Thyroid- Medullary cancer with moderate PR immunostaining of all tumor cells.

Thyroid- PR negative papillary carcinoma.

Urinary bladder- PR negative muscle-invasive urothelial carcinoma.

Uterus- Endometroid endometrium carcinoma with strong PR immunostaining of tumor and stroma cells.

Uterus- Leiomyoma depicting strong PR immunostaining of all tumor cells.

Uterus, cervix- PR negative squamous cell carcinoma. Stroma cells are PR positive, however.