Pituitary metastasis of small cell lung cancer: Two case reports

摘要

Pituitary metastasis is a rare manifestation of systemic malignancy accounting for approximately 1% of all pituitary tumors. Breast and lung tumors are the most common primary sources of metastases, yet other sites such as the gastrointestinal tract, prostate, kidney, thyroid, and pancreas have also been reported. The vast majority of pituitary metastasis are clinically silent; however, the most common presenting symptoms are usually related to pituitary dysfunction, with posterior pituitary predominance, as well as visual field defects secondary to mass effect. We present two cases of pituitary metastases, both middle-aged adult females with an extensive history of tobacco use presenting with new onset headaches and visual disturbances. The first case with pituitary metastasis as the first manifestation of underlying small cell lung carcinoma, and the second case with known metastatic small cell lung carcinoma receiving combination therapy with chemotherapy and immunotherapy who was found to have pituitary involvement. Both cases exhibited signs and symptoms of pituitary dysfunction requiring hormonal replacement therapy. Pituitary metastasis is a rare condition and often remains undiagnosed. Most metastatic tumors to the pituitary are clinically silent and diagnosed incidentally, and in many cases carries a poor prognosis. Distinguishing pituitary metastasis from other pituitary lesions based on clinical presentation and radiologic features is often challenging due to clinical and radiologic findings often being nonspecific, therefore a high index of clinical suspicion and physician awareness is of paramount importance. Management of pituitary metastasis may include surgery and radiotherapy, as well as, chemotherapy, immunotherapy and hormonal therapy, but evidence on the outcomes of these approaches is limited.