Role of Mediastinoscopy in Determining the Cause of Mediastinal Lymphadenopathy in Patients Referred to Shahid Beheshti Hospital of Babol

⁴ Cancer Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran

*Corresponding author: Novin Nikbakhsh, Cancer Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran. Email: novinsu@hotmail.com

EXTENDED ABSTRACT

Background

The mediastinum is the central compartment of the thorax between the pleural cavities and contains vital structures including the heart, great vessels, trachea, esophagus, phrenic and vagus nerves, thymus, and lymph nodes [1]. Establishing the cause of mediastinal lymphadenopathy is clinically important because radiologic enlargement alone does not define the underlying pathology, and definitive management frequently requires tissue diagnosis. Mediastinoscopy is a thoracic surgical technique used to directly examine the mediastinum and obtain tissue; it has high diagnostic performance in lung-cancer staging [2], can be performed through a minimally invasive cervical approach [3], and has long been regarded as a reference method for mediastinal tissue sampling [4].

Accurate mediastinal assessment is especially important in patients in whom malignancy is a concern because staging affects treatment selection and prognosis [5, 6]. Following the development of mediastinoscopy for assessment of enlarged mediastinal nodes and lung-cancer staging [7], the procedure became useful not only for malignancy but also for benign causes of lymphadenopathy such as sarcoidosis, tuberculosis, Hodgkin disease, lymphoma, histoplasmosis, and coccidioidomycosis [8]. Reported complications are uncommon, although vascular injury, pneumothorax, recurrent laryngeal nerve palsy, tracheal or esophageal injury, wound infection, major bleeding, and airway injury may occur [9]. Chest computed tomography is widely used for noninvasive assessment, but radiologic appearance does not always correspond to lesion pathology [10], and other tissue-sampling options include endoscopic ultrasonography-guided fine-needle aspiration and transbronchial needle aspiration [11]. Mediastinoscopy therefore remains a practical method for histopathologic diagnosis and staging [12].

The diagnostic question is particularly relevant when mediastinal lymph-node enlargement is present without a previously established pulmonary malignancy. In this setting, a tissue specimen can distinguish malignant disease from granulomatous, inflammatory, infectious, and other benign processes that may have overlapping imaging appearances. The article emphasizes that a reliable histopathologic diagnosis can guide subsequent therapeutic strategy and avoid basing management solely on radiologic enlargement. Because information on the diagnostic spectrum of mediastinal lymphadenopathy evaluated by mediastinoscopy in Iran was limited, the present study examined the causes identified in patients referred to Shahid Beheshti Hospital of Babol over a 10-year period and assessed whether pathology findings were related to patient age or sex.

Methods

This cross-sectional study included 36 patients hospitalized with mediastinal lymphadenopathy at Shahid Beheshti Hospital, Babol, Iran, from April 2009 through March 2020 and selected by census sampling. The recorded medical information of patients undergoing mediastinoscopy without known lung cancer was reviewed. Thus, the study was designed to characterize tissue diagnoses obtained specifically in patients investigated for mediastinal lymphadenopathy rather than to stage a pre-existing known lung malignancy. Mediastinoscopy was performed by a specialist physician for all included patients, and biopsy specimens were sent to the pathology department of Shahid Beheshti Hospital for final histopathologic diagnosis.

Data were extracted from medical records using a study checklist and included age, sex, the cause of lymphadenopathy, mediastinoscopic findings, pathology results, and lesion location. Quantitative variables were summarized using means and standard deviations, and qualitative variables using frequencies and percentages. Normality of age was assessed with the Kolmogorov-Smirnov test. Potential associations were analyzed using the Kruskal-Wallis test, Mann-Whitney test, and Fisher exact test as appropriate. Statistical analyses were performed with SPSS version 25, and the significance level was set at 0.05. The study received ethics approval from the Ethics Committee of Babol University of Medical Sciences (IR.MUBABOL.REC.1399.327).

Results

The 36 patients were 28-76 years old, with a mean age of 47.97±11.04 years. Age was reported as non-normally distributed according to the Kolmogorov-Smirnov assessment (P>0.05). Women comprised 27 patients (75.0%), and 9 patients (25.0%) were men. Histopathologic evaluation after mediastinoscopy classified 33 patients (91.67%) as having benign disease and 3 patients (8.33%) as having malignancy. Sarcoidosis was by far the most frequent diagnosis, occurring in 23 patients (63.90%). Active infection was reported in 4 patients (11.11%) in the narrative results, whereas the source table prints 11.10%; granulomatous lymphadenitis occurred in 3 (8.33%), bronchogenic cyst in 1 (2.78%), calcified granuloma in 1 (2.78%), and granulomatous changes in 1 (2.78%). All three malignant diagnoses were squamous cell carcinoma (8.33%).

Table 1. Distribution of patients according to pathology findings.

When pathology findings were examined by age and sex, patients with sarcoidosis had a mean age of 49.35 years (SD 11.66); 17 (73.91%) were women and 6 (26.09%) were men. Patients with active infection had a mean age of 44.00 years (SD 6.00), with 3 women (75.00%) and 1 man (25.00%). Mean age was 48.33 years (SD 6.65) for granulomatous lymphadenitis, 54.00 years for bronchogenic cyst, 28.00 years for calcified granuloma, and 33.00 years for granulomatous changes. The three patients with squamous cell carcinoma had a mean age of 52.00 years (SD 11.53); 2 (66.67%) were women and 1 (33.33%) was a man.

Overall pathology findings were not significantly associated with patient age (P=0.364) or sex (P=0.975). Because sarcoidosis was the predominant diagnosis, the investigators also assessed it separately. The mean age of patients with sarcoidosis was somewhat higher than that of patients without sarcoidosis, but the difference was not significant (P=0.454). Similarly, sarcoidosis status was not significantly associated with sex (P=0.841). Thus, although women constituted three quarters of the overall study population and nearly three quarters of patients with sarcoidosis, the observed distribution did not establish a statistically significant relationship between sex and the histopathologic diagnosis.

Table 2. Association of patient age and sex with pathology findings.

Conclusion

In this 10-year cross-sectional series, mediastinoscopy provided tissue diagnoses across a broad spectrum of mediastinal lymphadenopathy. Most diagnoses were benign, with sarcoidosis accounting for nearly two thirds of cases, whereas squamous cell carcinoma represented the malignant findings. Pathology results were not significantly related to age or sex. Consistent with the authors' conclusion, mediastinoscopy was useful for determining the cause of mediastinal lymphadenopathy and remained a reliable method for evaluating mediastinal lesions in this clinical setting.

Keywords: Chest Surgery, Lymphadenopathy, Mediastinoscopy, Mediastinum

REFERENCES

1. Deng CJ, Dai FQ, Qian K, Tan QY, Wang RW, Deng B, et al. Clinical updates of approaches for biopsy of pulmonary lesions based on systematic review. BMC Pulm Med. 2018;18(1):146. PMID: 30176840 DOI: 10.1186/s12890-018-0713-6
2. Harken DE, Black H, Clauss R, Farrand RE. A simple cervicomediastinal exploration for tissue diagnosis of intrathoracic disease; with comments on the recognition of inoperable carcinoma of the lung. N Engl J Med. 1954;251(26):1041-4. PMID: 13214387 DOI: 10.1056/NEJM195412232512602
3. Chauhan A, Kapoor S, Ganguly M, Nath P. Cervical mediastinoscopy: re-evaluation of an old technique in era of new imaging technology. Indian J Chest Dis Allied Sci. 2012;54(3):169-73.
4. Khorshidi H, Tarbiat M, Moradi A, Karimi B. Assesment of Mediastinoscopy Surgery Results in Patients with Mediastinal Tumor Reffered to Besat Hospital in Hamadan City from 2014 to 2019. Avicenna J Clin Med. 2020;27(2):94-99. DOI: 10.29252/ajcm.27.2.94
5. Samet JM. Smoking kills: experimental proof from the Lung Health Study. Ann Intern Med. 2005;142(4):299-301. PMID: 15710963 DOI: 10.7326/0003-4819-142-4-200502150-00012
6. Silvestri G, Gould M, Margolis M, Tanoue L, McCrory D, Toloza E. Noninvasive staging of non-small cell lung cancer: ACCP evidenced-based clinical practice guidelines (2nd edition). Chest. 2007;132(3 Suppl):178S-201S. PMID: 17873168 DOI: 10.1378/chest.07-1360
7. Carlens E. Mediastinoscopy: a method for inspection and tissue biopsy in the superior mediastinum. Dis Chest. 1959;36:343-52. PMID: 13807712 DOI: 10.1378/chest.36.4.343
8. Hammoud ZT, Anderson RC, Meyers BF, Guthrie TJ, Roper CL, Cooper JD, et al. The current role of mediastinoscopy in the evaluation of thoracic disease. J Thorac Cardiovasc Surg. 1999;118(5):894-9. PMID: 10534695 DOI: 10.1016/s0022-5223(99)70059-0
9. Harewood GC, Wiersema MJ, Edell ES, Liebow M. Cost-minimization analysis of alternative diagnostic approaches in a modeled patient with non-small cell lung cancer and subcarinal lymphadenopathy. Mayo Clinic proceedings. 2002;77(2):155-64. DOI: 10.4065/77.2.155
10. Goldstraw P, Kurzer M, Edwards D. Preoperative staging of lung cancer: accuracy of computed tomography versus mediastinoscopy. Thorax. 1983;38(1):10-5. PMID: 6845256 DOI: 10.1136/thx.38.1.10
11. Serna DL, Aryan HE, Chang KJ, Brenner M, Tran LM, Chen JC. An early comparison between endoscopic ultrasound-guided fine-needle aspiration and mediastinoscopy for diagnosis of mediastinal malignancy. Am Surg. 1998;64(10):1014-8. PMID: 9764715
12. Ghigna M, de Montpreville V. Mediastinal tumours and pseudo-tumours: a comprehensive review with emphasis on multidisciplinary approach. Eur Respir Rev. 2021;30(162):200309. PMID: 34615701 DOI: 10.1183/16000617.0309-2020
13. Shields TW. General thoracic surgery: Lippincott Williams & Wilkins. 2005.
14. Eldaboosy SA, Zeinnhom RA, Kanany H, Nour MO. The value of cervical mediastinoscopy in the diagnosis of mediastinal lesions. Egypt J Chest Dis Tuberc. 2015;64(3):755-60. DOI: 10.1016/j.ejcdt.2015.03.030
15. Zhu F, Ma D-C, Xu N, Xu X-Q, Lv L-P, Tang L, et al. Diagnostic Value of Video-assisted Mediastinoscopy and Endobronchial Ultrasound-guided Transbronchial Needle Aspiration for Mediastinal Lymphadenectasis without Pulmonary Abnormalities. Med Sci Monit. 2017;23:3064-3070. PMID: 28642455 DOI: 10.12659/msm.900968
16. Onat S, Ates G, Avcı A, Yıldız T, Birak A, Akgul Ozmen C, et al. The role of mediastinoscopy in the diagnosis of non-lung cancer diseases. Ther Clin Risk Manag. 2017;13:939-943. PMID: 28794637 DOI: 10.2147/TCRM.S144393
17. Glick RD, La Quaglia MP, editors. Lymphomas of the anterior mediastinum. Semin Pediatr Surg. 1999;8(2):69-77. PMID: 10344303 DOI: 10.1016/s1055-8586(99)70021-1
18. Valizadeh N, Farrokhi F, Mehdiughli M, Eishi Oskuie A, Oshnouei S, Noroozinia F. Etiologic assessment of mediastinal masses in patients of Emam Khomeinihospital in Urmia, Iran. Stud Med Sci. 2014;24(12):1036-9.
19. JAhanshahi A, Aalamshah S. Epidemiology of mediastinal masses during five years (1382-1387) in Ahvaz. 2009.
20. Ahmadi J, Kalantari M, Raeis Alsadat, Mehrabi V, Nahvi H. A review of mediastinal tumors in children. Tehran Univ Med J. 2004;62(4):345-350.
21. Vaziri M, Pazooki A, Zahedi-Shoolami L. Mediastinal masses: review of 105 cases. Acta Medica Iranica. 2009:297-300.