Complete heart block ensuing from a metastatic small cell carcinoma: a case report

Our plain-English summary of Complete heart block ensuing from a metastatic small cell carcinoma: a case report, by P. Pallangyo, G. Kweka, F. Lyimo, et al (Journal of Medical Case Reports, 2022).

The study

• Authors: P. Pallangyo, G. Kweka, F. Lyimo, H. Mayala, H.J. Swai, Z. Mkojera, N. Misidai, M. Komba, J. Millinga, S. Bhalia, F. Mwapinga, S. Wibonela, M. Janabi
• Journal: Journal of Medical Case Reports
• Published: 2022;16(1):77
• Type of article: Case report
• Cited by: 9 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Introduction: Notwithstanding the diagnostic and therapeutic advancements, the incidence of cardiac metastases has increased in recent decades. Lung cancers are the most common primary malignant neoplasms with cardiac metastasis potential. The clinical presentation of cardiac metastases is either silent or vague, and largely depends on the infiltrated location and tumor burden. Although arrhythmias are not uncommon in metastatic cardiac tumors, complete heart block is relatively a rare manifestation. We present a case of complete heart block due to a metastatic small cell carcinoma in a 67-year-old male of African origin.

Case Presentation: A 67-year-old male of African origin from rural Tanzania was referred to us for expert management. He is a retired agromechanic with over 30 years exposure to asbestos-containing brake linings. His past medical history was unremarkable, but the family-social history was evident for a heavy alcohol intake and chronic cigarette smoking. He presented with a 24-week history of progressive shortness of breath and an 8-week history of recurrent syncopal attacks coupled with a significant weight loss. He had normal echocardiographic findings, however, the electrocardiogram showed features of complete heart block. Chest X-ray showed a homogeneous opacification on the right side and computed tomography scan revealed a solid right lung mass with metastases to the liver, heart, bowels, and bone. He underwent bronchoscopy, which revealed an endobronchial mass obstructing the bronchus intermedius. Histological examination of a section of lung biopsy taken during bronchoscopy confirmed the diagnosis of a small cell carcinoma. The patient underwent dual chamber pacemaker implantation with successful sinus rhythm restoration. He made an informed refusal of chemotherapy and inevitably died 18 months post pacing.

Conclusions: Despite the advancements in medical diagnostics and management, lung cancers are often diagnosed in advanced stages, with an inevitable grave prognosis. Small cell carcinoma has the potential to metastasize to the heart, resulting in complete heart block.

© 2022. The Author(s).

In plain English

This case report described one man, a 67-year-old of African origin from the Kilimanjaro region of Tanzania. He was a retired agromechanic with over 30 years of exposure to asbestos-containing brake linings, and he also had a history of heavy alcohol intake and 20 pack-years of cigarette smoking. He came to care with 24 weeks of worsening shortness of breath, 8 weeks of repeated fainting, and weight loss. His heart rate was 32 beats per minute, and an electrocardiogram showed complete heart block, a serious heart rhythm problem. A CT scan showed a mass in the right lung with spread to the heart, liver, bowels and bone. A lung biopsy confirmed small cell carcinoma, and heart muscle tissue showed similar findings. A dual chamber pacemaker restored normal rhythm. He declined chemotherapy and died 18 months after pacing, and no autopsy was done. The authors concluded that small cell carcinoma can spread to the heart and cause complete heart block. The article listed the asbestos exposure as part of his history but did not discuss whether it played a role.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: case report (one patient)
• Who was studied: One 67-year-old man of African origin from the Kilimanjaro region of Tanzania, a retired agromechanic with a history of heavy alcohol intake (5 units/day) and chronic cigarette smoking (20 pack years), referred to the Jakaya Kikwete Cardiac Institute, Dar es Salaam
• Exposure: Over 30 years of exposure to asbestos-containing brake linings as an agromechanic; fiber type not stated. The man also smoked cigarettes (20 pack years) and drank heavily.
• Main results:
  • The patient had a 24-week history of progressive shortness of breath and an 8-week history of recurrent fainting (syncopal attacks), with weight loss.
  • The electrocardiogram showed complete heart block; the echocardiogram was essentially normal.
  • The CT scan showed a solid right lung mass with spread to the heart, liver, bowels and bone.
  • A lung biopsy taken during bronchoscopy confirmed small cell carcinoma.
  • A dual chamber pacemaker restored normal (sinus) rhythm.
  • The patient refused chemotherapy and died at home 18 months after the pacemaker was implanted.
  • The authors stated that, after an extensive literature search, they believed this was the first documented case of complete heart block caused by small cell carcinoma.
• The authors' conclusion: The authors concluded that small cell carcinoma, though rarely, can spread to the heart and cause complete heart block. They also concluded that lung cancers are often diagnosed at advanced stages with a grave prognosis, and that timely pacing restores rhythm and somewhat improves quality of life while the overall prognosis remains poor.
• Limitations the authors state:
  • A 3D or 4D doppler/duplex ultrasound would have helped but was unavailable because of its high cost.
  • No autopsy was performed after the patient's death.
  • The case was managed in a resource-limited setting with several diagnostic limitations.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer.

Medical terms in this study, explained in our Lexicon: Carcinoma, Lung Cancer, Neoplasm, Metastasis, Tumor Burden, Brake Lining, Chest X-Ray, Bronchoscopy.

Related studies

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• Primary small cell carcinoma of the pleura: a case report with immunohistochemical and molecular genetic analyses of KIT and PDGFRA genes — T. Terada (2010)
• Pleural Small Cell Lung Carcinoma: An Unusual Culprit in Pleural Effusion — O.D. Adejorin, A. Sodhi, et al. (2015)
• Small cell mesothelioma: A rare entity and diagnostic pitfall mimicking small cell lung carcinoma on fine-needle aspiration — Y. Zhang, A. Afify, et al. (2016)
• Pseudomesotheliomatous small-cell neuroendocrine carcinoma of the lung with calretinin expression — G.D. Exarchos, R.L. Attanoos (2015)
• Small cell carcinoma presenting with massive pleural spread mimicking malignant pleural mesothelioma — T. Takeda, M. Saitoh, et al. (2014)

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