Syndrome of inappropriate antidiuretic hormone secretion associated with oral squamous cell carcinoma

SIADH Induced by Pharyngeal Squamous Cell Carcinoma: Case Report and Literature Review

Background. The Syndrome of Inappropriate Antidiuretic Hormone (SIADH) is considered to be the most common cause of euvolemic hyponatremia. The most common malignancy associated with SIADH is small cell lung cancer. We present a rare case of a patient with SIADH secondary to well differentiated squamous cell carcinoma of the naso-oropharynx. Case. A 46-year-old Caucasian woman presented to emergency department with four-week history of progressive dysphagia. On examination, she was found to have a pharyngeal mass. CT scan and MRI of neck confirmed a mass highly suspicious of carcinoma. Patient's serum sodium level decreased to 118 mEq/L and other labs including serum and urine osmolality confirmed SIADH. She was started on fluid restriction and oral sodium tablets which gradually improved her serum sodium levels. Biopsy confirmed diagnosis of squamous cell carcinoma of pharynx. Conclusion. SIADH can be caused by squamous cell carcinoma. Appropriate management includes fluid restriction.

Review of paraneoplastic syndromes associated with oropharyngeal squamous cell carcinoma

Malignancies are usually preceded by the presence of various paraneoplastic syndromes (PNS), which could be the indirect and/or remote effects of the metabolites produced by neoplastic cells. PNS manifested by oropharyngeal squamous cell carcinomas, which is the most common head and neck malignancy, are highlighted in this review. Knowledge of the clinical spectrum of these syndromes will equip the oral physician for early diagnosis and management of these hidden malignancies, especially of the pharyngeal region.

Paraneoplastic syndromes in patients with oral cancer

The diagnosis of a paraneoplastic syndrome (PNS) may precede, follow or be concurrent with the diagnosis of a malignant tumor. There is increasing knowledge of association between PNS and head and neck cancers, but the relationship between oral cancer and paraneoplastic disease has not been previously investigated. PNS associated with head and neck cancer can be divided into six main groups: endocrine, cutaneous or dermatologic, hematologic, osteoarticular or rheumatologic, neurologic, and ocular syndromes. We have comprehensively reviewed the literature to evaluate the incidence of occurrence of PNS with oral cancer, and conclude that only endocrine and dermatologic PNS have been associated with oral cancer. Humoral hypercalcemia is the most frequent PNS related to oral cancer, and has a negative prognostic significance. Dermatologic PNS are less common, but when they occur, they may precede the diagnosis of the oral tumor. Awareness of these conditions is important for clinicians who deal with cancer.

Synchronous orofacial granulomatosis and mucoepidermoid carcinoma: paraneoplastic syndrome or coincidence?

Some malignant neoplasias induce the appearance of local or systemic manifestations at distant sites, which can act as indicators of their presence in a process named paraneoplastic syndrome. Granulomatous reactions have already been described related to malignancies. This report describes a case of synchronous orofacial granulomatosis and mucoepidermoid carcinoma and discusses the significance of this association.

The syndrome of inappropriate antidiuretic hormone secretion associated with chemotherapy for hypopharyngeal cancer

The syndrome of inappropriate antidiuretic hormone secretion (SIADH) is characterized by hyponatremia and the plasma hypoosmolality induced by water retention attributable to persistent antidiuretic hormone (ADH) release. It has been reported that SIADH may occur due to various factors in patients with malignant tumor. We report a case of hypopharyngeal cancer complicated by SIADH following chemotherapy. A 72-year-old woman with hypopharyngeal cancer was treated by oral administration of S-1 and intravenous administration of low-dose cisplatin following radiation therapy. General fatigue and coma occurred during the third course of this chemotherapy, using S-1 and low-dose cisplatin. We believed that she had SIADH because of the results of examinations including hyponatremia, serum hypoosmolality and increasing serum ADH level. We treated her by fluid restriction and intravenous administration of hypertonic saline and furosemide, and she recovered. Unfortunately, her hypopharyngeal cancer gradually progressed and she died of acute pneumonia three months later.