Masked diabetes insipidus in pituitary metastasis from breast cancer after thalamic biopsy: a case report

Background Symptomatic pituitary metastasis is rare; furthermore, it can result in diabetes insipidus and panhypopituitarism. Since diabetes insipidus is masked by concurrent panhypopituitarism, it can impede the diagnosis of pituitary dysfunction. Case presentation A 68-year-old Japanese female suffering from pituitary and thalamic metastases caused by untreated breast cancer, underwent a biopsy targeting the thalamus, not the pituitary. She lacked prebiopsy pituitary dysfunction symptoms; however, these symptoms unexpectedly occurred after biopsy. Diabetes insipidus was masked by corticosteroid insufficiency, and she showed normal urinary output and plasma sodium levels. Upon commencement of glucocorticoid replacement therapy, the symptoms of diabetes insipidus appeared. Conclusions In this case, thalamic biopsy, as opposed to pituitary biopsy, was performed to preserve pituitary function. However, pituitary dysfunction could not be avoided. Caution is necessary for asymptomatic patients with pituitary metastases as invasive interventions, such as surgery, may induce pituitary dysfunction. Moreover, with respect to masked diabetes insipidus, there is a need to carefully consider pituitary dysfunction to avoid misdiagnosis and delayed treatment.

Differential Diagnosis in Hypophysitis: First Report on a Spindle Cell Rhabdomyosarcoma of the Pituitary Gland

Pituitary gland metastases are very rare. Most patients with pituitary gland metastases are asymptomatic; therefore, most cases of this disease are diagnosed during autopsies. Moreover, the four most common primary tumors that metastasize to the pituitary gland are breast, lung, thyroid, and renal carcinomas. We present a very rare case of pituitary metastasis of spindle cell rhabdomyosarcoma (RMS). Our patient presented with headache, visual disorder, panhypopituitarism, and diabetes insipidus. Due to tumor expansion, resection was not possible, so diagnosis was confirmed by biopsy, and chemotherapy and irradiation were administered. Our patient showed widespread spindle cell RMS, which harbors a mutation of myogenic differentiation 1 (MYOD1) and is associated with a poor prognosis. Even high-risk patients can show a remission after chemotherapy and irradiation. In the cases with indistinct lesions in the sella region, pituitary metastasis should always be considered.

Shrinkage of a pituitary metastasis of melanoma induced by pembrolizumab: a case report

Background Pituitary metastases are rare, often deriving from lung or breast cancer owing to the upper vena cava proximity. Pituitary metastases can manifest with signs and symptoms of pituitary tumors, consequent to mass effect (headache, visual impairment) and/or hormonal alterations (hyperprolactinemia, hypopituitarism, and diabetes insipidus). Immune checkpoint inhibitors burst immunity against tumors, significantly increasing patients’ survival, but their autoimmune side effects frequently involve the skin, the gastrointestinal tract, and the endocrine glands (pituitary, thyroid, pancreas). Case presentation A 77-year-old Caucasian man had undergone trans-nasal sphenoidal surgery for a nonsecreting pituitary macroadenoma in 2001, without remnant or endocrine deficits. In 2016, he was operated for a shoulder melanoma. In February 2018, imaging evaluation demonstrated metastases in lung, liver, and femur. Therefore, treatment with pembrolizumab (anti-programmed death 1) was scheduled in May 2018, but, before starting this therapy, a brain computed tomography performed for a sudden loss of consciousness detected a sellar mass of 17 × 12 mm, which extended to the pituitary stalk and compressed the optic chiasma. Focused magnetic resonance imaging confirmed the size and characteristics of the lesion, while emergency evaluation of the hormonal profile demonstrated an impairment of adrenal and thyroid function. The pituitary lesion demonstrated a remarkable shrinkage (8 × 6 mm), which was confirmed by subsequent imaging evaluations. Conclusions This is the first case reporting on effectiveness of immune checkpoint inhibitors in a patient with pituitary metastasis from a melanoma.

Prostate Cancer Metastasis to the Pituitary Gland Manifesting as Corticosteroid Withdrawal, and the Impact of the Switch from Prednisone to Dexamethasone on Survival Time

Despite improvements in the diagnosis and treatment of cancers, the incidence of pituitary metastasis has increased. Prostate cancer metastasis to the pituitary, however, is rare, and these tumors usually grow rapidly. They are also more likely to be located in the posterior pituitary, and the presenting symptoms are often nonspecific, which makes early diagnosis challenging. The management of this condition is usually multidisciplinary, and requires careful assessment and decision making. We present a case of a patient who developed prostate cancer metastasis to the pituitary. In this report, we show that patients with prostate cancer on corticosteroid therapy who develop withdrawal symptoms or other endocrine symptoms should be assessed for pituitary and other brain metastasis. This case report also discusses the impact of switching from prednisone and abiraterone to dexamethasone and abiraterone. Our report shows that patients on abiraterone and prednisone whose PSA has increased, but who have no radiologic progression, may have their PSA controlled and thereby improved survival time when they are switched to abiraterone and dexamethasone.