Masked Diabetes Insipidus Hidden by Severe Hyponatremia: A Case of Pituitary Metastasis of Lung Adenocarcinoma

Pituitary metastasis from lung adenocarcinoma: A case report

BACKGROUND

Pituitary gland metastasis is an unusual event, and pituitary metastasis from lung adenocarcinoma is extremely rare and associated with poor prognosis. To date, approximately 15 cases have been reported.

CASE SUMMARY

Here, we present the case of a 64-year-old woman with pituitary metastasis derived from lung adenocarcinoma, which was difficult to distinguish from other sellar tumors. The patient presented to the neurosurgery clinic with blurred vision and intermittent headache. During hospitalization, brain computed tomography (CT) and magnetic resonance imaging revealed a pituitary macroadenoma. Chest CT revealed irregular nodules in the basal segment of the lower lobe of the left lung, which were likely lung cancer. Positron emission tomography-CT revealed a carbohydrate metabolism tumor in the lungs and sellar region, which was considered malignant. Postoperative pathological examination of the sellar tumor revealed lung adenocarcinoma.

CONCLUSION

Excision of pituitary metastases combined with radiotherapy and chemotherapy should be a priority treatment for patients with pituitary metastasis.

Case Report: Pituitary metastasis as a presenting manifestation of silent gastric cardia adenocarcinoma

Introduction

Pituitary metastases are very rare in cancer patients and often originate from lung or breast tumors. They usually occur in patients with known metastatic disease, but rarely may be the first presentation of the primary tumor.

Methods

We present the case of a 58 years-old-man who reported a three-month history of polyuria-polydipsia syndrome, generalized asthenia, panhypopituitarism and bitemporal hemianopsia. Brain-MRI showed a voluminous pituitary mass causing posterior sellar enlargement and compression of the surrounding structures including pituitary stalk, optic chiasm, and optic nerves.

Results

The patient underwent neurosurgical removal of the mass. Histological examination revealed a poorly differentiated adenocarcinoma of uncertain origin. A total body CT scan showed a mass in the left kidney that was subsequently removed. Histological features were consistent with a clear cell carcinoma. However, endoscopic examination of the digestive tract revealed an ulcerating and infiltrating adenocarcinoma of the gastric cardia. Total body PET/CT scan with 18F-FDG confirmed an isolated area of accumulation in the gastric cardia, with no hyperaccumulation at other sites.

Conclusion

To the best of our knowledge, there are no reports of pituitary metastases from gastric cardia adenocarcinoma. Our patient presented with symptoms of sellar involvement and without evidence of other body metastases. Therefore, sudden onset of diabetes insipidus and visual deterioration should lead to the suspicion of a rapidly growing pituitary mass, which may be the presenting manifestation of a primary extracranial adenocarcinoma. Histological investigation of the pituitary mass can guide the diagnostic workup, which must however be complete.

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.

Risk assessment, diagnosis, and treatment of cancer treatment-related adrenal insufficiency

INTRODUCTION

Adrenal insufficiency (AI) is an easily treatable, potentially life-threatening condition, which is increasingly recognized in malignancy. The recent introduction of immune checkpoint inhibitors, in particular, and increasing use of tyrosine kinase inhibitors have increased the frequency of AI in patients with malignancy. A review is therefore warranted to summarize current knowledge on the topic and guide safe clinical practices.

AREAS COVERED

Malignancy may directly impact the hypothalamic-pituitary-adrenal axis and cause AI, or their treatment including surgery, radiotherapy and medication. In this narrative review, we discuss new causes of AI, recognition of suggestive clinical features, diagnosis and subsequent treatment, aiming to avoid potentially fatal adrenal crisis (AC). Standard literature searching and authors assessment of clinical applicability were used.

EXPERT OPINION

Adrenal insufficiency can be easily treated once identified but life threatening if unrecognized. While use of new agents such as immune checkpoint inhibitors (ICIs) is increasing, greater understanding of the mechanism of AI is needed to target prediction tools and enhance risk stratification.