Paraneoplastic syndrome as the presentation of limited stage small cell carcinoma

Abstract

BackgroundSmall cell lung carcinoma (SCLC) is one of the deadliest forms of lung cancer due to its poor prognosis upon diagnosis, rapid doubling time, and affinity for metastasis. As 60–70% of patients with SCLC have disseminated disease upon presentation, it is imperative to determine the extent of disease burden for treatment. As a neuroendocrine carcinoma, clinicians must pay close attention to abnormal findings in a smoker that could lead to earlier diagnosis and better prognostication.Case presentationA 64 year-old 20-pack year smoker presented to the emergency department with nausea and vomiting for 3 days. No inciting events were elicited. History and review of symptoms were negative including symptoms most-commonly associated with malignancy such as fevers and weight loss. He also denied any pulmonary symptoms. Physical examination was benign except for right lung end-expiratory wheezing. Our patient was clinically euvolemic. Initial blood laboratories showed a sodium 110, serum osmolarity 227, and urine osmolarity of 579. Fluid restriction led to normalization of his sodium and resolution of nausea & vomiting. Chest radiography was obtained to follow-up on the wheezing, which was read as no acute cardiopulmonary disease by radiology. Due to high suspicion of SIADH from malignancy, a CT of the chest was performed which showed a conglomerate of nodules and opacities in the right upper lobe. Biopsy revealed SCLC. At outpatient follow-up, patient had a PET-CT showing one active mediastinal lymph node as the only site of metastasis. He received three round of chemotherapy, chest and prophylactic cranial radiation, and deemed in remission by oncology.Discussion and conclusionsDue to its affinity for metastases, 70% of patients with SCLC present with symptoms related to the spread of cancer to affected organ systems. Given the aggressive nature of this disease, screening measures have been implemented to help diagnose limited stage SCLC. Unfortunately, in our patient and many others, screening guidelines may fail to identify appropriate patients to scan. It is therefore imperative to use our clinical index of suspicion and identify any early presentations (including paraneoplastic syndromes) which may tip off the beginning stages of SCLC. This could improve survival rates by up to 45%.

A narrative review of progress in diagnosis and treatment of small cell lung cancer patients with hyponatremia

“…Clinically, patients with SCLC are often asymptomatic in the early stage, and hyponatremia is often overlooked (67). Patients are usually admitted to hospital for hyponatremia detected by electrolyte examination, and SCLC is eventually diagnosed after relevant examinations are completed.…”

Pre-operative Labs for Left Hemicolectomy Reveals Hyponatremia That Leads to Lung Mass Finding

“…The patient’s presentation with hyponatremia and lung findings on CT suggest a primary SCLC given the association with SIADH without invasion of the dysplasia of the colon biopsy and having an unremarkable liver on CT scan. It is important to identify SCLC in its early development because 70% of SCLC present with metastatic disease [ 3 ]. The current United States Preventive Services Task Force (USPSTF) recommends lung cancer screening in adults aged 50 to 80 years old who have a 20-pack-year smoking history and who currently smoke or have quit smoking cigarettes in the past 15 years.…”

Síndromes paraneoplásicos asociados a cáncer de pulmón

“…6 Estos anticuerpos onconeurales tienden a dirigirse no sólo a las células tumorales, sino también a las células del sistema nervioso tanto central como periférico, produciendo un amplio rango de manifestaciones clínicas. [7][8][9] Encefalitis límbica Síndrome neuropsiquiátrico con afectación a estructuras límbicas (hipocampo, hipotálamo y amígdala); caracterizado por cambios en la personalidad, pérdida de memoria a corto plazo, alteración de la función cognoscitiva y crisis convulsivas que progresan gradualmente de días a meses. El cáncer pulmonar se asocia frecuentemente a esta entidad (50% de los casos), la estirpe de células pequeñas es la que más tiende a desarrollarla (80% de los casos).…”

“…El cáncer que más comúnmente desarrolla estos síndromes paraneoplásicos es el pulmonar, dentro de los que destacan algunos como el síndrome de secreción inapropiada de hormona antidiurética y la hipercalcemia humoral maligna. 6,7 En este artículo de revisión se discutirán más a detalle los síndromes paraneoplásicos que se desarrollan en el cáncer pulmonar, así como el momento en que se tienden a presentar y el pronóstico que conlleva la presencia de cada uno. 6…”