Beyond the Dual Paraneoplastic Syndromes of Small-Cell Lung Cancer with ADH and ACTH Secretion: A Case Report with Literature Review and Future Implications.

Krishna Adit Agarwal,Myat Han Soe

doi:10.1155/2018/4038397

Krishna Adit Agarwal, Myat Han Soe

Open Access

https://doi.org/10.1155/2018/4038397

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Journal: Case reports in oncological medicine	Publication Date: Oct 18, 2018
Citations: 9	License type: CC BY 4.0

Affiliation: Baystate Medical Center

Abstract

We present a case of small-cell lung cancer (SCLC) with syndrome of inappropriate antidiuretic hormone secretion (SIADH) in which serum sodium gradually normalized with the onset of hypertension, refractory hypokalemia, and chloride-resistant metabolic alkalosis due to ectopic adrenocorticotrophic hormone (ACTH) secretion (EAS). In this case report, we discuss the diagnostic challenges of dual paraneoplastic syndromes with SIADH and EAS, management of SCLC with paraneoplastic endocrinopathies, and their prognostic impact on SCLC. In addition, we discuss neuroendocrine differentiation and ectopic hormone production in relation to intratumoral heterogeneity in SCLC and propose tumor microenvironment and hormonal and metabolic dependence as important determinants of tumor growth and survival.

Highlights

Small-cell lung cancer (SCLC) is an aggressive neuroendocrine subtype of lung cancer and is associated with paraneoplastic syndromes in about 20 to 40% of cases [1, 2]
The association of SCLC with SIADH is well known, with up to 15% of SCLC exhibiting SIADH [5], while 1% to 5% of SCLC has ectopic adrenocorticotrophic hormone (ACTH) secretion resulting in paraneoplastic Cushing syndrome [1, 6]
We present a case of SCLC with hyponatremia at presentation which normalized with the onset of ectopic ACTH secretion

Summary

Introduction

Small-cell lung cancer (SCLC) is an aggressive neuroendocrine subtype of lung cancer and is associated with paraneoplastic syndromes in about 20 to 40% of cases [1, 2]. When the Notch signaling pathway is suppressed, tumor cells remain in neuroendocrine phenotypes and have the potential to secrete various hormones and peptides leading to paraneoplastic syndromes [3, 4]. Though hyponatremia in SCLC is relatively easy to recognize, EAS can be overlooked due to lack of typical Cushingoid picture. Instead, it presents with muscle wasting, weakness, and syndrome of apparent mineralocorticoid excess (SAME), manifesting as resistant hypertension and hypokalemic metabolic alkalosis. We present a case of SCLC with hyponatremia at presentation which normalized with the onset of ectopic ACTH secretion

Case Description

Discussion

Findings

Future Implications