Lymph node cancer of the mediastinal or hilar region with an unknown primary site

Role of T0 status in overall survival for unresectable stage III non-small cell lung cancer: A NCDB analysis

OBJECTIVES

Occult primary non-small cell lung cancer (NSCLC) with mediastinal involvement is a known but rare clinical condition. Very limited retrospective data are available in the literature. Its prognosis and response to systemic chemotherapy have not been investigated with large scale data.

MATERIALS AND METHODS

Using National Cancer Database (NCDB), cases that had undergone radiation therapy without surgery for N2-3M0 NSCLC were selected. Demographics and survival data were compared between T0 and T1-4 groups. Survival analyses were conducted with Kaplan-Meier and log-rank tests. Cox proportional hazard models were used for univariate and multivariate analyses.

RESULTS

Between 2004 and 2016, 84,263 and 458 cases met criteria for unresectable stage III NSCLC with T1-4 and T0 stage, respectively. T0 status was associated with younger age, recent diagnosis (year 2010-2016), adenocarcinoma histology, N3 stage, and use of chemotherapy. Survival analysis demonstrated that those with T0 status had prolonged overall survival as compared to T1-4 counterparts in both overall and chemotherapy groups (p < 0.0001 for each). Five-year overall survival rates for T0 and T1-4 groups were 30.5% and 12.7% in all groups, and 33.6% and 14.6% in chemotherapy groups, respectively. Propensity score matching also demonstrated a statistically significant difference in overall survival (p < 0.0001). These findings are confirmed by independent analysis using Surveillance, Epidemiology, and End Results Program (SEER).

CONCLUSION

This large hospital-based study demonstrates the favorable prognosis for T0 status in the setting of unresectable stage III NSCLC. Researchers may consider it as distinct stage (e.g., stage IIC) for future studies.

Lobectomy for subsegmental lymph node metastasis of unknown origin

We report a very rare case of resected subsegmental lymph node metastasis of unknown origin. Hilar (N1) lymph node metastasis of unknown origin has previously been reported, but intrapulmonary lymph node metastasis has not been reported to date. At this patient's first visit to our hospital, an abnormal nodule was found on the upper lung lobe on a chest radiograph. After 4 years' follow-up, the nodule vanished, but a tiny nodule had emerged. 2-Fluoro-2-deoxy-D-glucose positron-emission tomography (FDG-PET) computed tomography was performed, and abnormal accumulation was observed only in the newly emerged intrapulmonary nodule. Right upper lobectomy was performed and a metastatic subsegmental lymph node, but no primary lesion, was found. Our observations suggest that evanescence of a suspicious primary lesion indicates the possibility of metastasis. FDG-PET was useful in this case for detecting lymph node metastases and demonstrating that the primary and further metastatic lesions were absent.

Outcomes of Stage III NSCLC with occult primary vs. known primary lesions

OBJECTIVES

Occult primary non-small cell lung cancer (OP-NSCLC) involving mediastinal lymph nodes without an identifiable primary tumor is a rare presentation, with little known about how outcomes compare to typical Stage III NSCLC. We reviewed our experience treating OP-NSCLC with definitive radiotherapy and compared outcomes to a contemporary cohort of stage III NSCLC patients.

MATERIALS AND METHODS

We reviewed 605 patients with stage III NSCLC staged with PET-CT and treated with definitive radiotherapy between 1998 and 2013. Overall survival, intrathoracic control, and freedom from distant metastasis were computed using Kaplan-Meier method and logrank comparison. Cox hazard ratios were used to perform univariate and multivariate analyses.

RESULTS

Twenty-one patients were identified with OP-NSCLC (3.5%). Patients with OP-NSCLC, as compared to known primary NSCLC, had significantly better 5-year rates of intrathoracic control (83.5% vs. 24.2%, P < 0.001), freedom from distant metastasis (59.0% vs. 26.3%, P = 0.003), and overall survival (61.6% vs. 15.2%, P < 0.001). Multivariate analyses confirmed occult primary as an independent prognostic factor associated with a 70% reduction in risk of intrathoracic failure, a 55% reduction in risk of distant metastasis, and a 70% reduction in risk of death.

CONCLUSION

To our knowledge, this is the largest reported series of OP-NSCLC and the first to compare it to a contemporary cohort of Stage III NSCLC with known primary lesion. Definitive radiation therapy was associated with favorable locoregional control and survival, particularly compared with typical stage III NSCLC. This difference suggests that occult primary NSCLC may be a distinct entity with different biology than typical NSCLC.

Lymph node cancer of the mediastinum with a putative necrotic primary lesion in the lung: a case report

Background

Although mediastinal lymph node cancer is presumed to originate in the lung, the primary site is usually unidentified, so the pathological course remains unclear. We recently encountered a case of mediastinal lymph node cancer having a putative primary lesion remaining in the lung as a necrotic focus.

Case presentation

The patient was a 56-year-old man who visited our department because computed tomography screening had revealed a nodular shadow in the lingular segment. However, on positron emission tomography, fluorine-18 deoxyglucose accumulation was detected in a subcarinal lymph node and not in the nodule in the lingular segment. Biopsy of the lung tumor and the lymph node was performed via minimal thoracotomy. Intraoperative pathologic examination showed necrosis alone and no malignant findings in the lung tumor. By contrast, carcinoma was detected in the lymph node. Additional subcarinal lymph node dissection was performed. Results of postoperative histopathologic examination indicated poorly differentiated adenocarcinoma of the subcarinal lymph node. Meanwhile, the nodule in the lingular segment was speculated to be a spontaneously resolved primary focus of lung cancer.

Conclusions

In this case, the primary lung cancer focus resolved spontaneously after lymph node metastasis, explaining the pathogenesis underlying mediastinal lymph node cancer of unknown primary site. For similar cases of malignancy, aggressive treatment, including surgery, is effective.

Lung Cancer Detected 5 Years after Resection of Cancer of Unknown Primary in a Mediastinal Lymph Node: A Case Report and Review of Relevant Cases from the Literature

We report the rare and interesting case of a primary lung cancer detected 5 years after cancer of unknown primary (CUP) of a mediastinal lymph node (LN) was resected. A 40-year-old male was diagnosed with adenocarcinoma of unknown primary in a mediastinal lymph node after resection of the mediastinal tumor. Five years after resection of the CUP in mediastinal LN, a small, abnormal nodular shadow in left upper lobe was detected by chest CT. This pulmonary tumor was diagnosed as a lung adenocarcinoma. The pathological and immunohistological findings of the resected pulmonary tumor resembled those of the LN resected 5 years before. We speculated that the pulmonary lesion represented primary lung cancer that enlarged later than the metastatic mediastinal LN. This case illustrates the importance of careful observation and long-term follow-up in patients treated for CUP of a thoracic LN.

Cisplatin plus Docetaxel Chemotherapy for Thoracic Lymph Node Metastasis from Cancer of Unknown Primary - Experience of Three Cases

The optimal chemotherapeutic regimen for cancer of unknown primary (CUP) remains uncertain. We encountered 3 cases with CUP who presented with thoracic lymph node metastasis. Detailed physical examination and diagnostic tests, including laboratory investigations, bronchoscopy, upper and lower gastrointestinal studies, computed tomography of the head, neck, abdomen and pelvis and ¹⁸F-fluorodeoxyglucose positron emission tomography, failed to identify the primary site in these cases. The patients were treated with the cisplatin plus docetaxel chemotherapy regimen. Concomitant thoracic radiotherapy was conducted in one patient and surgical resection in another. All patients showed good response to the chemotherapy and achieved long-term disease-free survival.

Adenocarcinomas of unknown primary (ACUP) of the mediastinum mimicking lymphoma: CT findings at diagnosis and follow-up

OBJECTIVE

To describe the computed tomography (CT) features at diagnosis and after treatment of adenocarcinoma of unknown primary (ACUP) mimicking lymphoma of the mediastinum.

METHODS

Fifteen patients with pathologically proven ACUP and with primarily mediastinal involvement were initially referred to the Hematologic Department of our institution with a suspected diagnosis of lymphoma, and accounted for our study population. Presenting symptoms and baseline biological values were analyzed. All thoraco-abdominal CT studies were reviewed for the location and size of the mediastinal involvement and associated findings. Follow-up chest CT was performed in 14 patients after radiotherapy, chemotherapy or surgical treatment.

RESULTS

The most frequent CT feature was a large anterior and middle mediastinal mass (67%), with no calcification. Associated findings included the presence of lung nodules (40%), compression of large mediastinal vessels (33%) and pleural effusion (27%). Follow-up CT, performed in 14 cases, suggested partial or complete responses in 7 patients (50%) 4 weeks after the treatment onset.

CONCLUSIONS

Mediastinal ACUP is a differential diagnosis of large mediastinal masses and is frequently associated with lung nodules and mediastinal vascular compression.

Metastatic thoracic lymph node carcinoma with unknown primary site

BACKGROUND

Metastatic cancer in thoracic lymph nodes without a primary site is rare. The purpose of this study is to draw attention to this probably underestimated entity, to speculate on its possible origins, and to suggest guidelines for its treatment.

METHODS

Eight heavy smokers with no past medical history of cancer were diagnosed at operation to have malignant cells in intrathoracic lymph nodes (N1 or N2) with no primary site in the lung. All patients underwent an exploratory thoracotomy with a presumed diagnosis of lung cancer except one who presented with a middle lobe mucosa-associated lymphoid tissue lymphoma. We reviewed the type of surgical resection, histologic and immunohistochemical analysis of resected specimens, treatments, survival, and long-term results.

RESULTS

Resections performed were pneumonectomy (n = 4), lobectomy (n = 3), and bilobectomy (n = 1). All patients underwent complete mediastinal lymph node dissection. Lung resection was performed for mucosa-associated lymphoid tissue lymphoma (n = 1) and for tumorlike lesions that appeared to be tuberculoma (n = 1) and intrapulmonary metastatic lymph nodes (n = 6). Malignant cells were located in intrapulmonary lymph nodes alone (n = 3) or also in mediastinal lymph nodes in three other cases. All these tumors were cytokeratin-positive, demonstrating their epithelial nature. Pulmonary origin was confirmed in two cases (thyroid transcription factor 1-positive and thyroglobulin-negative). No other origin could be demonstrated by immunochemistry. Three patients died within the first year. All other patients are still alive without recurrence (Kaplan-Meier 5-year survival rate, 62.5%).

CONCLUSIONS

Frequency of metastatic cancer in thoracic lymph nodes without a primary site is probably underestimated because the cancer is routinely diagnosed by mediastinoscopy and considered as metastatic disease not amenable to operation. The origin of the disease, either pulmonary, endogenous, or from extrathoracic sites, is often difficult to assess. Nevertheless, our data confirm those of the literature and demonstrate that survival can be increased by operation. This implies diagnosis of the entity and consideration that thoracic lymph node involvement can apparently be isolated and therefore resectable.

Carcinoma positive for Epstein-Barr virus staining. Mediastinal lymph node origination?

A 44-year-old man undergoing radical excision of metastatic carcinoma of the mediastinal lymph node with unknown primary sites remains alive and disease-free 14 years after surgery. His cancer cells were positive for the Epstein-Barr virus, which may have been related to the oncogenesis of this tumor. This case is unique in the patient's long, disease-free survival and its positive presence of the Epstein-Barr virus.

Continuous infusion cisplatin and etoposide chemotherapy for cancer of unknown primary site (CUPS) in Taiwan, a region with a high prevalence of endemic viral infections

BACKGROUND

To evaluate the efficacy and toxicity of cisplatin/etoposide continuous infusion chemotherapy for cancer of unknown primary site in Taiwan, a region with a high prevalence of endemic viral infections.

METHOD

Between April 1994 and February 1996, 20 patients with a diagnosis of CUPS were treated, including 15 males and five females, of average age 63.3 years (range 41-83 years). Continuous intravenous infusion of etoposide 80 mg/m2 and cisplatin 25 mg/m2 was given for 3 days every 3 weeks. Pretreatment tumor marker and viral serology studies were performed for baseline evaluation. Nearly two-thirds of the patients had poorly differentiated carcinoma. The average number of metastatic sites was 2.65 (range 1-4), with liver and lymph node involvement predominating.

RESULTS

The overall response rate was 25% (95% CI 17.7-32.3%); 30.7% for poorly differentiated cancers and 25% for well differentiated cancers. Median survival was 4 months (range 1-12 months), 4.8 months for patients attaining partial response. Toxicity was moderate, grade 3 and 4 neutropenia occurred in 55% and grade 3 and 4 thrombocytopenia in 40%; other toxicities were mild. CA125 and CA199 were elevated in more than 50% of patients. Viral serology studies were not significantly different from those of the indigenous population.

CONCLUSION

Etoposide and cisplatin combination chemotherapy has modest activity in patients with extensive CUPS and, at the schedule and dosage given, it is associated with moderate toxicity.

Primary unknown cancer in pulmonary hilar lymph node with spontaneous transient regression: report of a case

A 69-year-old man was referred to our hospital in December 1993 because an abnormal mass had been detected in the right pulmonary hilum. Computed tomography (CT) of the chest revealed a swollen hilar lymph node between the right middle and lower lobe bronchi, and an adherent tumor in the right ventrobasal segment (S8). Chest roentgenogram in February 1994, however, showed no evident tumor in the right lung field. In March 1996, the mass in the right pulmonary hilum reappeared on chest roentgenogram. Chest CT revealed a swollen hilar lymph node between the right middle and lower lobe bronchi, but there was no tumor in right S8. The patient underwent video-assisted thoracoscopy on 17 May 1996. Intraoperative needle biopsy of the node revealed cancer cells. We performed right middle and lower bilobectomy with mediastinal dissection. Histological diagnosis revealed a large cell carcinoma almost completely occupying a hilar lymph node. The resected middle and lower lobes showed no tumors, except for a coagulation necrosis measuring 1.5 cm in diameter in S8b, corresponding to the site where a tumor shadow had been depicted on the CT image in December 1993. We concluded that the coagulation necrosis might have been the primary site of the tumor, which had spontaneously regressed and then appeared in the metastatic interlobar node.