The identification of sMPLC preoperatively presents a clinical challenge, as it is often difficult to differentiate a second primary cancer from a satellite, metastatic, or recurrent lesion [6, 8]. This has a significant impact on preoperative planning and treatment, as sMPLC favors surgical resection, unlike primary metastatic lung cancers [4, 6]. In our case, we began with percutaneous CT-guided sampling of both nodules and performed a whole-body PET‒CT scan to rule out possible lymph node involvement and metastasis. We also included a brain MRI in the preoperative workup to ensure that no mets could be identified. Notably, in patients with sMPLC, lymph node metastasis, extranodal extension, vascular invasion, and adenosquamous carcinoma are associated with a very poor prognosis, with one study estimating a significant difference in 5-year survival of 15.5% compared with 52.5% in patients without those features [9]. When lymph node invasion occurs, sampling of the node and identification of tumor markers with concomitant genetic testing may assist clinicians in determining the type of cancer for better management [3, 9].
There also seems to be an increasing trend in the diagnosis of sMPLC [8]. However, owing to ambiguous classifications and guidelines for treatment, adequately assessing the effectiveness of diagnostic and management strategies for patient outcomes remains difficult [6]. Some databases have been adopted to track cases of sMPLCs, and molecular biomarkers seem to play an important role in diagnostic accuracy [6]. Thus, it is important to document cases such as ours to continue to elucidate diagnostic techniques and how our choice in management via bilateral stage lobectomies contributes to the outcome and survivability of sMPLC.
Synchronous lung cancers are typically treated via single, double lobectomy, or pneumonectomy depending on the location of the tumors within the lungs [3]. Initial surgeries target the larger lesion first, followed by resection of the contralateral lesion, depending on the patient’s lung viability and comorbid factors [3, 8]. Wedge and segmental resections are thought to increase the local recurrence rate, but they could be considered for patients with poor lung function who may not tolerate larger resections [6, 9]. Staged lobectomy procedures offer the best outcomes on the basis of the current literature [7, 8, 9]. This patient requires close surveillance over the next two years to detect early recurrence, but 5-year survival rates are favorable on the basis of the cancer presentation and treatment, male sex, young age, and cessation of smoking, with high remaining lung function [4, 8, 9].
In conclusion, synchronous multiple primary lung cancer rarely occurs, and distinguishing between primary lung cancer and metastatic lung cancer is difficult. This poses a diagnostic challenge for clinicians and usually requires more extensive workup to ensure proper management. Our patient was diagnosed with two histologically different types of adenocarcinomas in both the right upper and left upper lobes of the lung, without evidence of metastasis, and was treated with a staged bilateral upper lobectomy. The patient remains cancer free one year after diagnosis and has adequate lung function. However, close follow-up is needed to assess for recurrence, particularly within the first two years. On the basis of the current literature, the workup and management of this patient are likely to yield favorable 5-year survival outcomes and could be employed for future cases of sMPLC.