Head and neck cancer is the fifth most common cancer worldwide . In the United States, head and neck cancers account for 3.3% of all malignancies . The cervical lymph nodes are a common site of metastasis for cancers originating in the upper aerodigestive tract. Rarely, cancers originating from sites other than the head and neck can metastasize to the cervical lymph node chain. However, genitourinary tract neoplasms make up a significant proportion of these cancers and should be considered in the differential diagnosis of neoplastic lesions of the head and neck . A study reported and identified 31 (3.7%) of 845 genitourinary tumors metastasized to the head and neck and 21 tumors (2.5%) metastasized to the cervical lymph nodes . Ferlito et al.  reported a series of genitourinary tumors and found this group to be the third most frequent tumor site to metastasize to the supraclavicular fossa.
Epithelioid tumors in the head and neck are common and include both primary and metastatic lesions . Metastatic lesions, clinical factors, tumor location, and ancillary immunohistochemical studies must be taken into consideration to help the clinician and the pathologist to determine the site of origin. A group of unusual, but important, primary tumors that can metastasize to the head and neck are genitourinary tumors consisting of carcinoma of the prostate (CAP), renal cell carcinoma (RCC), which is also known as clear cell carcinoma, and bladder cancer, of which the most common type by far is transitional cell carcinoma (TCC) .
Prostate carcinoma is the second most common cause of cancer death among American men . It has been established that more than 30% of men over the age of 50 will develop this devastating disease . Established risk factors include age, ethnicity and family history . Although most of the metastatic prostate cancers will arise in the axial skeleton or the pelvic lymph nodes, it has been reported to spread to the axillary and cervical lymph nodes of the head and neck region [3, 4]. A retrospective study identified 26 cases of metastatic prostatic carcinoma involving the supraclavicular lymph nodes, which were the most common site of invasion . One study reported 26 cases in which the most common primaries with metastasis to the sphenoid sinus were prostate adenocarcinoma, with an incidence of 20% . Ferlito et al.  reported 5 of 21 cases (24%) were normal for serum acid phosphatase, 7 of 20 cases (35%) had no evidence of metastases to bones, 8 of 19 (42%) cases had normal rectal examination and 19 of 26 cases presented with physical findings of urinary obstructive symptoms or enlarged lymph nodes despite no history of prostate cancer. This shows that the diagnosis of prostate cancer cannot rely only on clinical or serological examination. Rather it also depends highly on the combination of cytological or histological features with immunostaining using prostate-specific antigen and prostatic acid phosphatase.
Renal cell carcinoma accounts for 3% of all malignancies and can metastasize to any location in the body, and its propensity to metastasize to unusual sites has been well documented. Approximately, 30% of patients with RCC present with metastatic disease, 25% with locally advanced renal carcinoma, and 45% with localized disease . It is the third most frequent neoplasm to metastasize to the head and neck region preceded only by breast and lung cancer . In spite of being reported infrequently, head and neck region metastases may be linked to RCC in up to 8–15% of cases . Specifically, regions in the head and neck include the paranasal sinuses, larynx, jaws, temporal bones, thyroid gland, and parotid glands [13, 14]. RCC metastases to the nose and paranasal sinuses are most commonly affected followed by the tongue .
In a minority of patients, the classical presentation of RCC manifests itself in the classical triad of pain, hematuria, and flank mass. Unfortunately, head and neck metastasis from RCC is usually a manifestation of widespread disease and it is often indicative of advanced disease. RCC may remain clinically occult for most of its course. The expected 5- and 10-year survival rates for these patients are 5–30 and 0–5%, respectively . Approximately, 75% of patients with RCC metastasize most commonly to the lungs, 20% to bone, 18% to liver, 36% to soft tissue and 8% to central nervous system .
Bladder neoplasm accounts for 2–6% of all tumors, with bladder cancer becoming the fourth most common cancer occurring in the United States, with an increase in incidence after 65 years . Bladder cancer is the second most prevalent cancer for men and the tenth most prevalent cancer for women . Bladder carcinoma metastases are commonly found in bone (75%), followed by lymph nodes (26%) and lung (20%) . Supraclavicular lymph node metastases are rare and indicate widespread disease with poor prognosis. Metastases of the head and neck regions are also uncommon and their most frequent sites are the brain, supraclavicular nodes, neck nodes and the skull . Hessan et al.  reported and identified 3 of 207 cases (1.4%) for cervical lymph nodes. Very few cases of TCC metastasize to the oral cavity, including one reported case in the maxilla  and seven reports identified in the mandible . Only four cases have been described in the oral soft tissues one in the tongue  and one in the submandibular gland .
Metastatic tumors to the head and neck are extremely rare. Therefore, the literature is based largely on sporadic case reports. Possible routes of metastasis to the head and neck include arterial, venous and lymphatic circulations. These include paravertebral venous plexus (Batson’s) or through the thoracic lymphatic duct. Overall, correct diagnosis is important, as these patients may achieve remission and prolonged survival with chemotherapy, irradiation and/or hormonal therapy.