Metastatic small cell carcinoma of the lung presenting as pituitary apoplexy and Cushing's syndrome

Pituitary metastases from neuroendocrine neoplasms: case report and narrative review

PURPOSE

Pituitary metastases (PM) are uncommon findings and are mainly derived from breast and lung cancers. No extensive review of PM from neuroendocrine neoplasms (NENs) is on record. Here we describe a clinical case of PM from pancreatic NEN and review the clinical features of PM from NENs reported in the literature.

METHODS

A case of PM from a pancreatic NEN followed at our institution is described. We also reviewed the 43 cases of PM from NENs reported in the literature.

RESULTS

A 59-year old female patient, previously submitted to duodeno-cephalo-pancreasectomy for a well-differentiated pancreatic NEN, with known hepatic metastases, underwent a ⁶⁸ Ga-DOTATOC PET/CT that revealed an uptake in the pituitary gland. A subsequent MRI displayed a pituitary lesion, with suprasellar extension. After a hormonal and genetic diagnostic workup that excluded the diagnosis of MEN 1, the worsening of headache and visual impairment and the growth of the lesion lead to its surgical removal. A pituitary localization of the pancreatic NEN was identified. Regarding the published cases of PM from NENs, the most common tumour type was small cell lung cancer (SCLC), accounting for nearly half of the cases, followed by bronchial and pancreatic well differentiated NENs. The most frequent symptom was a variable degree of visual impairment, while headache was reported in half of the cases. Partial or total anterior hypopituitarism was present in approximately three quarters of the cases, while diabetes insipidus was less common. The most frequent treatment for PM was surgical resection, followed by radiotherapy and chemotherapy. The clinical outcome was in line with previous reports of PM from solid tumours, with a median survival of 14 months. Surgery of PM was associated with prolonged survival.

CONCLUSIONS

PM from NENs have clinical features similar to metastases derived from other solid tumours, albeit the involvement of the anterior pituitary seems more frequent; a thorough pituitary hormonal evaluation is mandatory, after focused radiological studies, particularly if a surgical approach is considered. The optimal management of PM remains disputed and seems mainly driven by the aggressiveness of the primary tumour and the presence of symptoms. In well-differentiated NENs, particularly in the case of symptomatic PM, surgical removal may be a reasonable approach.

Symptomatic Pituitary Metastasis as Initial Manifestation of Renal Cell Carcinoma: Case Report and Review of Literature

Metastasis to the pituitary gland is extremely rare (∼2% of sellar masses). Clinical, biochemical, and radiologic characteristics of pituitary metastasis are poorly defined and can be difficult to diagnose before surgery. We present an unusual case with pituitary metastasis as the first manifestation of renal cell carcinoma (RCC). A 70-year-old male presented with acute onset of weakness, dizziness, diplopia, and progressively worsening headache. The initial CT head revealed a heterogeneous sellar mass measuring 2.8 × 1.9 × 1.7 cm. A follow-up MRI showed the sellar mass invading the right cavernous sinus. The presumptive diagnosis was a pituitary macroadenoma. Physical examination revealed bilateral 6th cranial nerve palsy and episodes of intermittent binocular horizontal diplopia. Hormonal testing noted possible secondary adrenal insufficiency (AM serum cortisol: 3.3 mcg/dL, ACTH: 8 pg/mL), secondary hypothyroidism (TSH: <0.01 mIU/L, FT4: 0.7 ng/dL), secondary hypogonadism (testosterone: 47 ng/dL, LH: 1.3 mIU/mL, and FSH: 2.3 mIU/mL), and elevated serum prolactin (prolactin: 56.8 ng/ml, normal: 4.0-15.2 ng/ml). IGF-1 level was normal at 110 ng/mL (47-192 ng/mL). The patient was discharged on levothyroxine and hydrocortisone therapy with plans for close surveillance. However, his condition worsened over the next three months, and he was subsequently readmitted with nausea, vomiting, and hypernatremia secondary to diabetes insipidus. Repeat MRI pituitary showed an interval increase in the size of the sellar mass with suprasellar extension and a new mass effect on the optic chiasm. The sellar mass was urgently resected via a trans-sphenoidal approach. The tumor was negative for neuroendocrine markers and pituitary hormone panel, ruling out the diagnosis of pituitary adenoma and triggered workup for metastatic renal cell carcinoma, clear cell type. The diagnosis of renal cell carcinoma was confirmed by the diffuse and strong staining for renal cell carcinoma markers (Pax-8, RCC-1, and CD10). A follow-up CT scan noted large right renal mass measuring 11 × 10 × 11 cm. The patient underwent a cytoreductive robotic right radical nephrectomy for WHO/ISUP histologic grade II clear cell RCC, stage pT2b pNX pM1. He subsequently received fractionated stereotactic radiotherapy to the pituitary gland. He is presently stable with no radiological evidence of progression or new intracranial disease on subsequent imaging. Pituitary metastasis most commonly occurs from breast, lung, or gastrointestinal tumors but also rarely from renal cell carcinoma. Biochemical findings such as panhypopituitarism, acute clinical signs such as headache, visual symptoms, and diabetes insipidus and interval increase in sellar mass in a short time interval should raise suspicion for sellar metastasis.

Sellar Metastases: Diagnosis and Management

Sellar metastases account for 0.87% of all intracranial metastases. They are usually asymptomatic and can be the first manifestations of some occult malignancy. The diagnosis is made mainly during the screening of patients with known primary lesions or can present with neurologic or hormonal changes related to compression or invasion of surrounding structures. Differentiating these lesions from other more common lesions such as pituitary adenoma maybe difficult. Management is mainly aimed at the primary lesion and is palliative to improve quality of life or for pathologic confirmation.

Prolactin-Secreting Lung Adenocarcinoma Metastatic to the Pituitary Mimicking a Prolactinoma: A Case Report

BACKGROUND AND IMPORTANCE

Metastasis to the pituitary gland is uncommon in patients with systemic disseminated cancer. Individual articles have reported cases of pituitary metastasis mimicking a prolactinoma, but no case of a prolactin-secreting tumor metastasizing to the pituitary mimicking a prolactinoma has been reported so far.

CLINICAL PRESENTATION

This article reports a 67-yr-old man with a recent onset of headaches, ophthalmoplegia, hypopituitarism, and hyperprolactinemia who was initially diagnosed with prolactinoma and given bromocriptine in the local hospital. Because of vomiting after taking drugs, he was transferred to our hospital for further diagnosis and treatment. Serum prolactin was elevated up to 1022 ng/mL, and pituitary magnetic resonance imaging revealed a 2.9 × 2.8 × 2.3 cm sellar mass with pituitary apoplexy, for which endoscopic transsphenoidal surgery was performed. Postoperative pathology and western blotting disclosed a prolactin-positive metastatic lung adenocarcinoma. Whole exome sequencing revealed a number of gene mutations including KRAS, PIK3CA, ALK, and CTNNB1. The patient died of deterioration of the lung disease 3 mo after the initial diagnosis.

CONCLUSION

To the best of our knowledge, this is the first report of a prolactin-secreting tumor metastasizing to the pituitary mimicking a prolactinoma as confirmed by both immunohistochemistry and western blot. Prolactin secretion is rare and elusive, and may associate with specified gene mutations.

Pituitary metastasis of lung neuroendocrine carcinoma: case report and literature review

Metastasis to the pituitary gland is an unusual situation in clinical practice, but the frequency thereof is increasing due to the increased survival of cancer patients, and greater availability of imaging. In most cases, they are found between the sixth and seventh decades of life, as determined in image examination of patients with known malignant neoplasm, but, generally, asymptomatic with respect to pituitary involvement. The most common primary sites are breast in women and lung in men. We present the case of a 64-year-old patient with clinical visual changes, polyuria, polydipsia, and decreased level of consciousness whose tests showed pan-hypopituitarism, hypernatremia and low urine specific gravity, and extensive mass in sellar region. Diabetes insipidus was confirmed and treated, corticotrophic and thyroid deficits were corrected and then the patient underwent resection by transsphenoidal surgery. The histopathological and immunohistochemistry analysis revealed pituitary metastasis of lung neuroendocrine tumor. Subsequently, a chest CT scan showed pulmonary mass consistent with primary neoplasm. Despite the water and electrolyte correction and intravenous glucocorticoid replacement, the patient continued to show decreased level of consciousness due to compression of the brain stem by the pituitary mass, evolving to death. The purpose is to call attention to the differential diagnosis of invasive lesions of the sellar region, mainly in individuals over 50 years and/or when associated with diabetes insipidus, as it may be a case of metastasis, although there is no known primary neoplasm.

Diagnosis and management of isolated pituitary metastasis from adenocarcinoma of unknown origin presenting as loss of libido

Pituitary gland metastasis from primary tumours is uncommon on its own. Rarely, some of these primary tumours may be of unknown origin. This metastasis to the pituitary gland could manifest as diabetes insipidus, cranial nerve palsies, headaches, fatigue and other symptoms. In rare cases, it could present as loss of libido. We describe here this rare presentation, loss of libido, examine the diagnosis and management undertaken, and provide a systematic review of the literature for similar cases.

Clinical and biochemical characteristic features of metastatic cancer to the sella turcica: an analytical review

BACKGROUND AND OBJECTIVES

Sellar metastasis is uncommon and poorly characterized as published data include small series of subjects. This study's goal is to identify unique features that differentiate this entity from other sellar masses such as pituitary macroadenomas.

METHODS

Published cases of pathologically-confirmed sellar metastasis along with our experience in such patients over a 6-years period were reviewed (total = 129). As a control group, we reviewed similar data on 55 patients with pituitary macroadenomas managed over the same time-period. Presenting symptoms, pituitary dysfunction were analyzed using univariate, multivariate and receiver operating characteristic (ROC) analyses.

RESULTS

Sellar metastasis has equal gender distribution with a median patient-age of 56 years. The most common primary malignancy was breast cancer (29%) in women and lung cancer (30%) in men. Sellar metastasis was the first manifestation of cancer in over 40% of patients. Common presenting symptoms included headaches, visual field deficits, abnormal eye motility and diabetes insipidus. These symptoms were less frequent among patients with pituitary macroadenomas. Univariate regression analyses showed that headaches, abnormal eye motility, visual field deficits and diabetes insipidus were each predictive of metastatic disease. ROC analysis combining all 4 features revealed an AUC of 0.953 with a sensitivity of 0.818 and a specificity of 0.935. Using the multivariate regression, abnormal eye motility and/or diabetes insipidus independently predicted metastatic disease.

CONCLUSIONS

Sellar metastasis should be suspected in patients presenting with sellar masses, abnormal eye motility and/or diabetes insipidus even those without known malignancy since pituitary metastasis can often be the first manifestation of cancer.

A lifelong smoker with hypopituitarism: rethinking the hypothesis of a tumor in the hypophysis

Pituitary adenomas are the most common cause of a sellar mass. Metastases to the pituitary gland, a rare occurrence, may mimic benign pituitary adenomas. We report here a case of a 61-year-old woman with an 80-pack-year smoking history who presented with headache and diplopia. Visual field testing demonstrated bitemporal hemianopsia. Pituitary MRI revealed a 2.0 cm sellar mass impinging upon the optic chiasm. Hypopituitarism was present, with no evidence of diabetes insipidus. The patient was referred to our service for transsphenoidal resection of a presumed pituitary macroadenoma. As part of her preoperative evaluation, a chest radiograph was obtained, which showed a large hilar mass. In light of the patient's extensive smoking history, the differential diagnosis was expanded to include metastatic lesion to the sella. Transsphenoidal resection of the tumor was performed and histopathology revealed small cell carcinoma. The patient received chemotherapy, but died 18 months later due to widespread brain metastases. Although the presence of diabetes insipidus may help to discriminate between pituitary adenomas and metastatic lesions, this is not a sensitive finding. This case illustrates the need for maintaining a high index of suspicion for pituitary metastasis in patients with known risk factors for malignancy.

Neuroendocrine tumor of unknown origin metastasizing to a growth hormone-secreting pituitary adenoma

BACKGROUND

Metastasis of a neuroendocrine tumor to the anterior pituitary is extremely rare.

METHODS

A 55-year-old woman presented with features suggestive of acromegaly and bone and joint pain. A bone scan suggested metastatic disease. A biopsy of the lumbar spinal lesions revealed a neuroendocrine tumor. Magnetic resonance imaging of the sella demonstrated a lesion with parasellar and suprasellar extensions. Given the need for tissue diagnosis and optic compression, the sellar lesion was removed via transsphenoidal hypophysectomy.

RESULTS

Histology of the biopsy indicated two different tumors in close association. One showed histological features of a pituitary adenoma, whereas the other was a neuroendocrine carcinoma. The pituitary adenoma was immunopositive for growth hormone (GH), whereas the neuroendocrine carcinoma was immunopositive for serotonin and bombesin and immunonegative for GH.

CONCLUSIONS

This is the first report of a serotonin and bombesin immunopositive neuroendocrine tumor of unknown primary origin metastatic to a GH-secreting pituitary adenoma, resulting in acromegaly.

[Pituitary metastasis presenting as diabetes insipidus: a report of four cases and literature review]

INTRODUCTION

Pituitary metastases are a rare cause of central diabetes insipidus and usually complicate advanced cancers.

CASE REPORTS

We report four cases in which diabetes insipidus revealed a metastatic stage of a lung (two cases) or a breast (two cases) cancer. One patient presented with a panhypopituitarism, three had diabetes insipidus including one with corticotroph insufficiency. In one case, the cerebrospinal fluid analysis showed a lymphocytic meningitis. On brain magnetic resonance imaging there was an absence of high intensity signal in the posterior pituitary lobe (one case) or an infiltration of the posterior lobe (three cases).

CONCLUSION

Breast and lung malignancies are the most frequent causes of metastasis of the pituitary gland. In most cases there are often other metastatic locations; however insipidus diabetes can reveal the metastatic stage of the cancer. A pituitary biopsy may be necessary to obtain the diagnosis.

An isolated pituitary metastasis as presentation of a differentiated hepatocellular carcinoma mimicking a nonfunctioning macroadenoma

The differential diagnosis of sellar masses may be complex. Metastatic disease constitutes 1% of all pituitary lesions and sometimes mimics the clinical-radiological presentation of pituitary adenoma. The definitive diagnosis usually relies on histology, but occasionally even histological features of pituitary metastasis may resemble those of adenomas. We present a patient initially diagnosed with pituitary adenoma, but whose clinical course finally revealed pituitary metastasis of a hepatocellular carcinoma. The existing literature on this topic is reviewed.

Ectopic pro-opiomelanocortin syndrome

Ectopic POMC syndrome remains one of the most challenging differential diagnoses in endocrinology. Recent progress in the understanding of the tissue specific regulation of POMC gene expression and new insights into the processing of the POMC peptide in nonpituitary tissues has helped elucidate some of the molecular events leading to ectopic expression and secretion of POMC peptides. Corticotropin and other POMC-derived peptides have diverse effects on adrenal steroidogenesis, growth, and extra-adrenal tissues. Differences in POMC gene regulation in the corticotrope versus ectopic POMC-producing tumors provides a scientific framework for the clinical distinction between eutopic and ectopic Cushing's syndrome. In an attempt to revisit recent basic and clinical advances in the diagnosis of ectopic POMC syndrome the authors undertook an extensive literature review of 530 cases in 197 published papers and provided a molecular biologic, demographic and diagnostic update. According to this review, the four most common causes of ectopic POMC syndrome are the small cell carcinoma of the lung (27%), bronchial carcinoids (21%), islet cell tumor of the pancreas (16%), and thymic carcinoids (10%). Although the clinical features of patients with ectopic POMC syndrome are similar to those with Cushing's disease, subgroup analysis reveals a broad spectrum of severity and progression of signs and symptoms of hypercortisolism. The endocrine workup of a patient with suspected ectopic POMC syndrome includes the establishment of pathologic hypercortisolism, diagnosis of corticotropin dependency, and the differential diagnosis of corticotropin-dependent Cushing's syndrome. The use of a variety of baseline endocrine values, dynamic endocrine testing, and invasive procedures leads to the correct diagnosis in the majority of patients with ectopic POMC syndrome. Diagnostic imaging, including conventional radiological techniques and somatostatin receptor scintigraphy, aids in the correct localization and eventual treatment of ectopic POMC production.