In the era of increasing survival of cancer patients and advanced imaging techniques, there are also changes in the presentation, diagnosis, and outcomes of patients with pituitary metastasis, according to a case series published in Pituitary.
The clinical presentation of pituitary metastasis is variable and can include visual disturbances, cranial nerve palsies, or pituitary dysfunction. These metastases are most frequently diagnosed in patients with a history of cancer, but may also be the first sign of malignancy or detected incidentally. Treatment options can be directed to the primary tumor or to the metastasis. The goal of the current study was to report the manifestations, diagnosis, management, and outcomes of patients with pituitary metastasis from a single pituitary center over the last decade.
Records of all cases of pituitary metastasis included in the pituitary registry of the department of endocrinology at Queen Elizabeth Hospital Birmingham in the United Kingdom between January 2009 and December 2018 were reviewed. The researchers identified 18 cases (14 women; median age, 61.5 years) with histopathological confirmation of pituitary metastasis (8 patients) or diagnosis based on clinical/radiologic features (10 patients).
Most patients (72%) had a known history of malignancy, with lung cancer (7 patients; 39%) and breast cancer (6 patients; 33%) being the most common. In the remaining cases (28%), pituitary metastasis was the first manifestation leading to diagnosis of the primary tumor.
The most common presenting symptoms of pituitary metastasis were visual dysfunction (9 patients; 50%), with hypopituitarism recorded in a small minority (3 patients; 17%). Gonadotropin, adrenocorticotropic hormone, and thyrotropin deficiency were diagnosed in 85%, 67%, and 46% of cases, respectively; diabetes insipidus was present in 17%. Incidental diagnosis of pituitary metastasis was reported in one-third of the cases (6 patients; 33%).
On pituitary magnetic resonance imaging, suprasellar extension was seen in 94% of patients (17/18), cavernous sinus extension in 39% (7/18), sphenoid sinus invasion in 11% (2/18), and extension through the sellar floor to the clivus in 22% (4/18).
Fractionated radiotherapy was the most common method of primary management for pituitary metastasis (8 cases; 44%), followed by tanssphenoidal surgery (3 cases; 17%), whereas monitoring was chosen in one-third of patients (6 cases; 33%). Of the 10 cases with follow-up imaging, radiologic progression was seen in 7 patients at a median time of 9 months after primary management of pituitary metastasis.
At last follow-up, gonadotropin deficiency was present in 92% of patients (12/13), adrenocorticotropic hormone deficiency in 82% (9/11), thyrotropin deficiency in 64% (9/14), and diabetes insipidus in 22% (4/18). Vision was improved in 4 of 8 cases with baseline optic nerve dysfunction and follow-up visual assessment, whereas in the other cases it was stable or deteriorated.
During a median follow-up of 11 months, 13 patients died as a result of their malignancy, with probability of survival of 49% at 1 year and 37% at 2 years.
The limitations of the study, according to the researchers, included the small sample size, retrospective design, and lack of histopathological confirmation of pituitary metastasis in several cases.
“Further outcome-oriented studies are needed to determine the safety and efficacy of different management strategies for [pituitary metastasis],” concluded the researchers.
Lithgow K, Siqueira I, Senthil L, et al. Pituitary metastases: presentation and outcomes from a pituitary center over the last decade [published online March 18, 2020]. Pituitary. doi:10.1007/s11102-020-01034-2