Patient description: A Pap smear in a 54-year-old woman revealed abnormal cervical squamous intraepithelial/glandular lesion. She tested positive for HPV 16. She is sexually active with her husband and has 4 children. She is menopausal and uses no contraception. She smokes and drinks alcohol frequently. She is otherwise healthy. She was offered conization.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  Advanced Malignant Solid Neoplasm Carcinoma of Unknown Primary Metastatic Adrenal Gland Pheochromocytoma Metastatic Kidney Medullary Carcinoma Metastatic Malignant Germ Cell Tumor Metastatic Malignant Solid Neoplasm Metastatic Paraganglioma Metastatic Penile Carcinoma Metastatic Skin Squamous Cell Carcinoma Small Cell Carcinoma Stage III Adrenal Cortex Carcinoma AJCC v7 Stage IV Adrenal Cortex Carcinoma AJCC v7 Stage IV Penile Cancer AJCC v7 Stage IV Renal Cell Cancer AJCC v7 Unresectable Adrenal Gland Pheochromocytoma Unresectable Paraganglioma Unresectable Skin Squamous Cell Carcinoma Unresectable Solid Neoplasm Vascular Neoplasm Be willing and able to provide written informed consent/assent for the trial Have measurable disease based on 1.1 or irRECIST; only cohort 9 and 10 can have evaluable disease (non-measurable lesions); tumor lesions situated in a previously irradiated area are considered measurable if progression has been demonstrated in such lesions; patients may have bone metastatic disease evaluable according to tumor evaluation best suitable and accepted for the tumor type evaluated Have one of the following advanced (unresectable and/or metastatic) solid tumor indications that has progressed following standard therapies, where standard therapies are available Squamous cell carcinoma of the skin Small cell malignancies of non-pulmonary origin Adrenocortical carcinoma Medullary renal cell carcinoma Carcinoma of unknown primary Penile carcinoma Vascular sarcoma  Is currently participating and receiving study therapy or concurrent chemotherapy, immunotherapy, biologic, or hormonal therapy for cancer treatment at the time of administration of first dose of trial treatment; continuation of hormone replacement therapy is permitted; stable regimens of hormonal therapy i.e. for prostate cancer (e.g. leuprolide, a gonadotrophin releasing hormone [GnRH] agonist), ovarian, or breast cancer are not exclusionary Has a diagnosis of immunodeficiency or is receiving systemic steroid therapy or any other form of immunosuppressive therapy within 7 days prior to the first dose of trial treatment Has a known history of active TB (bacillus tuberculosis) Hypersensitivity to pembrolizumab or any of its excipients Has not recovered (i.e., =< grade 1 or at baseline) from adverse events due to a previously administered agent; Note: subjects with =< grade 2 neuropathy are an exception to this criterion and may qualify for the study; Note: if subject received major surgery, they must have recovered adequately from the toxicity and/or complications from the intervention prior to starting therapy Has a known additional malignancy that is progressing or requires active treatment; exceptions basal cell carcinoma of the skin or squamous cell carcinoma of the skin that has undergone potentially curative therapy or in situ cervical cancer, and diseases for which the treatment could reasonably pembrolizumab and are not part of the excluded tumor type list or not eligible for the phase I trial Has known active central nervous system (CNS) metastases and/or carcinomatous meningitis; subjects with previously treated brain metastases may participate provided they are stable (without evidence of progression by imaging for at least four weeks prior to the first dose of trial treatment and any neurologic symptoms have returned to baseline), have no evidence of new or enlarging brain metastases, and are not using steroids for at least 7 days prior to trial treatment; this exception does not carcinomatous meningitis which is excluded regardless of clinical stability Has active autoimmune disease that has required systemic treatment in the past 2 years (i.e. with use of disease modifying agents, corticosteroids or immunosuppressive drugs); replacement therapy (eg., thyroxine, insulin, or physiologic corticosteroid replacement therapy for adrenal or pituitary insufficiency, etc.) is not considered a form of systemic treatment; immunosuppressive corticosteroid doses (> 10 mg prednisone daily or equivalent) within 4 weeks prior to the first dose of pembrolizumab; Note: corticosteroids given within 24 hours of an imaging study for purposes of pre-medication in patients with hypersensitivity to radiologic contrast agents are allowed Has known history of, or any evidence of active, non-infectious pneumonitis Has an active infection requiring systemic therapy