Incidental finding of lung adenocarcinoma following routine bullectomy and pleurodesis on a young patient: a case report

Abstract

Lesson

Spontaneous pneumothorax is a rare complication of lung cancer. In this report, we present a case of a patient with recurrent pneumothorax undergoing routine bullectomy and pleurodesis and lung adenocarcinoma is diagnosed incidentally. The prognosis for patients with untreated lung cancer has always been unfavourable with a median survival time of only 10 to 14 months, even for early-stage disease. Once the diagnosis is established, an effective treatment should be instituted without delay. Spontaneous pneumothorax is a rare manifestation of lung cancer and the relative risk for developing lung cancer should be considered with the patients with recurrent spontaneous pneumothorax.

Many studies report that spontaneous pneumothorax is a rare manifestation of primary lung cancer^1–3 and spontaneous pneumothorax can be the first sign of lung cancer. ⁴ To the best of our knowledge, there have been lack of studies examining the relative risks of developing lung cancer in patients who developed spontaneous pneumothorax. We present a rare case of an incidental finding of lung adenocarcinoma after a routine bullectomy and pleurodesis for recurrent spontaneous pneumothorax.

Case presentation

A 40-year-old man with background of previous multiple pneumothoraxes underwent a right bullectomy with talc pleurodesis in 2022. His histopathology showed an incidental finding of lung adenocarcinoma (100% solid variant, TTF1 positive, Napsin negative, P40 negative). The maximum dimension was 95 mm and it extended into right lower lobe and focally into the chest wall. From the multidisciplinary team (MDT) discussion, due to abnormal morphology of the lungs, no further surgical or medical management was deemed necessary at that time. In 2023, his annual surveillance computed tomography (CT) scan confirmed a recurrent disease with possible chest wall involvement (Figure 1). In July 2023, he was taken back to theatre, and it was found that the tumour was extending from right upper lobe invading anterolateral superior chest wall. Partial second, third and fourth ribs at tumour site were resected and extrapleural extended right upper lobectomy was performed. Tumour was however suspected to involve mid aspect of the main pulmonary artery (PA). Once PA branches to right middle and lower lobes were identified and dissected free, main PA was divided proximal to right middle and lower lobe branches. Following heparin injection, PA reconstruction was performed by continuous 3-0 prolene suture. The chest wall was repaired using bovine pericardium patch and secured on the chest wall with Vicryl sutures. The histopathology showed adenocarcinoma with pathological stage T4N0 (TNM 8th edition) and tolerated one cycle of adjuvant chemotherapy due to pneumonia requiring hospital admission with antibiotics.

Figure 1.

CT thorax confirms a recurrent disease with possible chest wall involvement (top, transverse plane; bottom, coronal plane).

Following his right upper lobectomy, middle and lower lobes failed to expand into the cavity due to his previous pleurodesis. This has left him with a chronic apical cavity, which has unfortunately become infected. A CT scan suggested the presence of right apical pneumothorax secondary to potential bronchopleural fistula (BPF). A bronchoscopy was performed to exclude BPF. Right middle lobe bronchus was found to be narrowed and intraoperative bronchial washing suggested the presence of Aspergillus fumigatus.

In February 2024, the patient underwent right cavernostomy, debridement of empyema cavity and pectoral myoplasty. The microbiology confirmed aspergilloma and the patient was discharged with a course of anti-fungal antibiotics.

Discussion

In this case report, we identified two important clinical issues. Firstly, the prognosis of lung cancer even for early-stage disease is poor and therefore immediate action is needed, and effective treatment should be instituted without delay. Secondly, spontaneous pneumothorax can be a rare manifestation of lung cancer.

Adenocarcinoma accounts for approximately 50% of all lung cancers ⁵ and it is also the most common histologic type of lung cancer in never or light smokers. ⁶ Quadrelli et al. report that patients with incidentally detected lung cancer are more likely to have earlier-stage disease and the incidence of adenocarcinoma is significantly higher in asymptomatic patients. ⁷ These findings are consistent with our patient.

The prognosis for patients with untreated lung cancer has always been unfavourable with a median survival time of only 10–14 months, even for early-stage disease.^8–10 Several studies have reported a significant correlation between histological type and tumour growth rate and squamous cancer is generally faster growing than adenocarcinoma.^11,12 However, there is a significant overlap across all tumour types and therefore prediction of tumour behaviour cannot be reliably based on histological differentiation. Also, lung cancer can be rapidly fatal and individual predictors of tumour progression are not yet available. So, once the diagnosis is established, effective treatment should be offered to the patient without delay. We argue that our patient should have been initially offered lobectomy or sublobar resection as a definitive management of lung adenocarcinoma, despite unfavourable lung morphology.

Spontaneous pneumothorax as a complication of early lung cancer is rare, comprising only 0.05% of all cases of pneumothoraxes. ¹³ Chen et al. report that higher frequency of spontaneous pneumothoraxes is observed with a greater risk of lung cancer. ¹⁴ They also report that if the patient develops spontaneous pneumothorax more than twice a year, the risk of cancer increases more than approximately 30 times. ¹⁴ Therefore, we suggest that in cases of recurrent spontaneous pneumothorax, the patient should be evaluated in a more detailed fashion, and further investigation can be useful with suspicion of an underlying pulmonary malignancy.

The mechanism of development of spontaneous pneumothorax from lung cancer is not fully understood, but several theories have been advanced. Firstly, Tsukamoto et al. demonstrated that rupture of the necrotic neoplastic tissue in the pleural cavity may contribute to the development of spontaneous pneumothorax. ¹⁵ Mawatari et al. showed that it may be caused by the rupture of the necrotic tumour nodule or necrosis of subpleural metastases. ¹⁶ Furthermore, the tumour at the lung periphery may obstruct bronchioles and lead to local overdistension and rupture of the lung. ¹⁷ Finally, most patients with chronic obstructive pulmonary disease may rupture bullae, following the disturbance of the lung architecture due to bronchial cancer. ¹⁸

Conclusions

The foundation of clinical decision-making relies on a careful balance of competitive risks related to the natural course of the disease, life expectancy and impact of treatment. Once the diagnosis is established, an effective treatment should be instituted without delay. Spontaneous pneumothorax is rarely seen as a complication of lung cancer. The relative risk for developing lung cancer should be considered when treating patients with recurrent spontaneous pneumothorax, especially if the frequency is more than twice a year.