Mediastinal lymph node carcinoma of an unknown primary site: clinicopathological examination

Unusual local and distant metastases after complete resection of roentgenographically occult squamous cell carcinoma

Roentgenographically occult squamous cell carcinoma (ROSCC) was reported to have been cured after complete resection. We experienced unusual local and distant metastases after complete resection of a ROSCC of left B6 bronchus. During the operation due to the proximal bronchial stump being positive for squamous cell carcinoma (SCC), a left lower sleeve lobectomy was performed. Six years after the operation, a chest CT showed no abnormal shadows. 6 months later a PET-CT showed metastases on bilateral supraclavicular lymph nodes, mediastinal lymph nodes, and the right adrenal glands. A biopsy of the right supraclavicular lymph node revealed that it was a metastatic SCC. The possibility of recurrence from a second pulmonary SCC might still remain. A prolonged follow-up over many years is desirable for a heavy smoker with a ROSCC.

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.

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.

Relapsed cervicomediastinal lymph node carcinoma with an unknown primary site treated with TS-1 alone: a case report

Background

Cervicomediastinal lymph node carcinoma with an unknown primary site is quite rare, and useful treatment of these diseases has not been established. We report here the case of a patient successfully treated with TS-1 alone after the relapse of cervicomediastinal lymph node carcinoma with an unknown primary site.

Case presentation

A 62-year-old man was referred to our hospital because of cervicomediastinal lymph node swelling and high serum levels of carbohydrate antigen 19-9 and carcinoembryonic antigen. Fluorodeoxyglucose-positron emission tomography/computed tomography revealed an accumulation of fluorodeoxyglucose in the left supraclavicular lymph nodes, mediastinal lymph nodes, and the pelvic cavity. Colonoscopy revealed rectal cancer, which was diagnosed by biopsy as a tubular adenocarcinoma. Because metastases from rectal cancer to the cervicomediastinal lymph nodes are rare, the patient underwent thoracoscopic mediastinal lymphadenectomy. A biopsy specimen from the paraaortic lymph nodes demonstrated papillary adenocarcinoma that was pathologically different from the rectal cancer; therefore, a diagnosis of mediastinal carcinoma with an unknown primary site was established. The patient underwent low anterior resection of the rectum for the rectal cancer, and no abdominal lymph node metastasis (pMP, N0/stage I) was found. Although radiotherapy was performed for the cervicomediastinal lymph nodes, the mediastinal carcinoma relapsed after 6 months. Because the patient desired oral chemotherapy on an outpatient basis, TS-1 was administered at a dosage of 80 mg/day for 2 weeks, followed by a 1-week rest. TS-1 treatment resulted in a decrease in the size of the cervicomediastinal lymph nodes, and the serum tumor marker levels decreased to normal after the fourth course. The patient continued TS-1 treatment without adverse events and is currently alive without recurrence or identification of the primary site at the 32nd month after TS-1 treatment.

Conclusion

This is the first reported case of relapsed cervicomediastinal lymph node carcinoma with an unknown primary site treated by TS-1 alone. TS-1 treatment for the carcinoma with an unknown primary site may be useful in patients who are not candidates for systemic platinum-based chemotherapy.