Pleural carcinoid diagnosed via video-assisted thoracoscopy biopsies in a patient with recurrent unilateral pleural effusion at St. Francis hospital Nsambya: a case report

Abstract

Background

Pulmonary carcinoids are rare neuroendocrine tumors accounting for less than 1% of all lung cancers. They are classified into two subcategories; typical and atypical carcinoids with the latter tending to grow faster. Historically, open thoracotomy was the standard approach for pulmonary resection. However, in the recent years, video-assisted thoracoscopy has gained popularity and become the preferred technique for resectioning pulmonary carcinoids. This report details the diagnosis and management of a pleural carcinoid tumor in a patient with recurrent unilateral pleural effusion.

Case presentation

A 77-year-old African male with a history of hypertension and heart failure with reduced ejection presented with a 6-month history of an irritating non-productive cough, occasional productive episodes and exertional dyspnea but no history of hemoptysis, chest pain, orthopnea, evening fevers, or significant weight loss. Despite multiple interventions, including tube drainage and antituberculosis medications, symptoms persisted. A chest X-ray was performed and it revealed a homogeneous opacity on the left, and a computed tomography scan showed mild pleural thickening especially at the bases. Video-assisted thoracoscopy was performed revealing thickened pleural and biopsies confirmed a diagnosis of malignant carcinoid tumor. The patient underwent successful pleurodesis, resulting in significant improvement.

Conclusion

This case highlights the pivotal role of video-assisted thoracoscopy in diagnosing and managing rare cases such as pulmonary carcinoids when less invasive methods such as thoracentesis fail.

Background

Pulmonary carcinoids are rare neuroendocrine tumors, constituting approximately 0.2–2% of the population [1]. They are classified into two subcategories, namely typical carcinoids and atypical carcinoids, with the latter comprising only 10–15% of the cases. A study conducted among patients with pulmonary neuroendocrine tumors indicated that approximately 80% of pulmonary carcinoids are centrally located within the lung while 20% are in peripheral regions [2] and are typically associated with the airways. Historically, pulmonary carcinoid tumors exhibit heterogeneous patterns including alveolar, organoid, trabecular, spindle and solid patterns [3]. Cases have been reported where pleural carcinoids present as exudative pleural effusions yet aspirates were negative for infectious disease after thorough work-up [4]. Previously, open thoracotomy was the standard approach for pulmonary resection. However, in the recent years, video-assisted thoracoscopy (VAT) has gained popularity and become the preferred technique for resectioning pulmonary carcinoids [2].

Video-assisted thoracoscopy (VAT) has emerged as a crucial tool, replacing open procedures for lung and pleural biopsies. It offers high diagnostic accuracy with fewer complications compared with open procedures. The diagnostic accuracy of VAT in diagnosing cancer and tuberculosis of the pleura is approximately 95% [5]. VAT is commonly used to evaluate pleural effusions when less invasive tests such as thoracentesis are inconclusive [6] and also plays a role in pleurodesis when chemical pleurodesis is contraindicated or ineffective. VAT is a viable alternative to open thoracotomy for both diagnostic and therapeutic purposes in lung and pleural lesions. Studies show no significant difference in long term survival between VAT and open procedures but VAT has fewer postoperative complications and a shorter hospital stay [7].

VAT is particularly beneficial for the elderly patients [7] and those who cannot tolerate general anesthesia. It can be performed using general anesthesia with selective intubation or local anesthesia as awake video assisted thoracoscopy (AVAT) [8]. Although AVAT has shown comparable outcomes with VAT in procedures such as pleural biopsies, wedge resections, decortications, and lobectomies [9], VAT remains the superior alternative due to its higher overall diagnostic accuracy and less postoperative pain [10]. When comparing diagnostic efficacy and safety profiles, AVAT pleural biopsy has demonstrated equal or improved outcomes in patients with undiagnosed pleural effusions [8]. However, VAT is still preferred because it provides a more controlled environment and has a lower risk of complications [11]. It is also associated with a shorter hospital stay and quicker recovery times [10].

There is a gap in the current understanding and management of pleural carcinoids especially in regions with limited access to advanced diagnostic tools such as magnetic resonance imaging (MRI). Therefore, this case report aims to address the gap by highlighting the effectiveness of VAT in accurately diagnosing and managing pleural carcinoids thereby improving patient outcomes and informing clinical practices in similar contexts.

Case presentation

A 77-year-old African male with a history of hypertension and heart failure with reduced ejection (HFrEF) presented with a 6-month history of an irritating nonproductive cough, occasional productive episodes, and exertional dyspnea. Despite multiple previous admissions and interventions such as tube drainage and anti-TB medications, the symptoms persisted. Antituberculosis (anti-TB) medications were started on the presumption that the pleural effusion could have been caused by TB; however, they were stopped in 2 weeks due to no reported improvement in symptoms. The patient’s daily home medications included; amlodipine and furosemide with a surgical history of appendectomy. He had no known allergies and was a retired teacher with long-term exposure to chalk dust and 6 years living under an asbestos roof. He was a non-smoker who consumed alcohol occasionally. The patient had no family history of malignancy and he was human immunodeficiency (HIV) seronegative.

On physical examination, his vital signs showed a blood pressure of 149/80 mmHg, a temperature of 36.3%, SpO₂ 89–91% on room air and a respiratory rate of 38 bpm. Cardiovascular examination was normal while respiratory examination revealed stony dull percussion and reduced air entry on the left side. Initial investigations included an echocardiogram showing an ejection fraction of 36% with grade III diastolic dysfunction and thoracostomy drainage that yielded 2.2L of blood-stained fluid (Fig. 1). Pleural fluid analysis indicated a transudate by Light’s criteria and was negative for TB. A chest X-ray showed a minimal rib crowding of the left hemithorax and a homogeneous opacity (Fig. 2). A computed tomography (CT) scan revealed mild pleural thickening especially at the bases (Fig. 3).

Fig. 1.

One liter of hemorrhagic fluid and cells consisting mainly of blood cells

Fig. 2.

X-ray showing minimal rib crowding of the left hemithorax and a homogeneous opacity

Fig. 3.

CT scan showing mild pleural thickening

Video assisted thoracoscopy (VAT) was performed revealing thickened pleural and a biopsy confirmed a malignant carcinoid tumor (Fig. 4, Fig. 5). The patient underwent pleurodesis with 60 units of bleomycin resulting in a significant reduction of pleural fluid output to less than 50 ml per day allowing for the discontinuation of underwater drainage. Post pleurodesis, the patient showed significant clinical improvement with no recurrence of pleural effusion and marked improvement in dyspnea. The final diagnosis was a malignant carcinoid tumor of the pleura.

Fig. 4.

VAT showing thickened pleura

Fig. 5.

VAT of the different sites

Discussion

Pleural effusions are a frequent cause of hospital admissions at Mulago hospital in Uganda. On a global scale, tuberculosis remains one of the most frequent causes of pleural effusions [12]. Despite this prevalence, the diagnostic challenge arises when standard tests such as contrast-enhanced CT of the thorax, pleural fluid cytology, cultures, acid fast bacilli stain, and gene X-pert for TB return with negative results. In this case, the absence of a definitive diagnosis from these initial tests prompted the use of video assisted thoracoscopy (VAT) with subsequent harvesting of lung and pleural tissue for histology.

Pleural metastases are generally associated with metastatic adenocarcinoma and are frequently associated with tumors of the lung [13]; however, in this case, there was no evidence of malignancy from other sites based on physical examinations and comprehensive investigations done. Given the patient’s history of asbestos exposure, differential diagnoses included mesothelioma and pleural squamous cell carcinoma, both of which are known to cause malignant pleural effusions and are associated with previous asbestos exposure ([14], [15]).

In cases where initial histopathologic results are inconclusive, immunohistochemistry plays a crucial role in confirming the diagnosis. Carcinoid tumors being neuroendocrine in nature often exhibit specific immunohistochemical traits including the presence of neuropeptides like chromogranin A and synaptophysin, dense core membrane granules on electron microscopy and neuron-specific enolase [16]. Additional markers such as CD56 and thyroid transcription factor 1 can also aid in the diagnosis of neuroendocrine tumors [17] although TTF1 has been found to be sensitive but not specific for pulmonary carcinoids [18].

The utilization of VAT in this case was pivotal, with a diagnostic accuracy of approximately 95% for detecting malignancies and tuberculosis of the pleura [5]. It offers a minimally invasive approach to obtain biopsies reducing the need for more invasive procedures like open thoracotomy. This case illustrates the utility of VAT in diagnosing and managing pleural effusions when initial noninvasive tests are inconclusive.

Conclusion

This case highlights the pivotal role of video assisted thoracoscopy (VAT) in diagnosing and managing rare cases such as pulmonary carcinoids. Our patient with a history of hypertension and heart failure was ultimately diagnosed with a malignant carcinoid tumor of the pleura via VAT following initial inconclusive investigations. This highlights VAT’s effectiveness as both a diagnostic and therapeutic tool, particularly in complex cases.

Abbreviations

VAT

Video assisted thoracoscopy

CT

Computed tomography

AVAT

Awake video-assisted thoracoscopy

NET

Neuroendocrine tumor

TB

Tuberculosis

HIV

Human immunodeficiency virus

MRI

Magnetic resonance imaging

SpO2

Saturation of peripheral oxygen

Author contributions

All authors contributed to the drafting and critical revision of the paper and gave conclusions approving the release of the version.

Funding

No funding to declare.

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Declarations

Ethics approval and consent to participate

Ethical approval for this case report was obtained from the St. Francis Hospital Nsambya Hospital Research Ethics Committee (SFHN-2024–151). Written informed consent was obtained from the patient prior to participation. Confidentiality and anonymity were strictly observed, ensuring no identifying information was disclosed. All procedures were performed in compliance with the relevant guidelines and regulations of good clinical practice and human protection of ICH-6.

Consent for publication

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Competing interests

All the authors in this case report do not have any competing interests.