A case of long-term survival after pulmonary resection for metachronous pulmonary metastasis of basaloid squamous cell carcinoma of the esophagus

Abstract

INTRODUCTION

Basaloid squamous cell carcinoma of the esophagus (BSCE) is a rare malignancy among esophageal cancers. We reported a case of 63-year-old woman with metachronous pulmonary metastasis of BSCE, successfully treated by metastasectomy of the left lung.

PRESENTATION OF CASE

Biopsy specimens of upper gastrointestinal fiberscopy led to diagnosis of poorly differentiated squamous cell carcinoma of the esophagus. Computed tomography revealed metastatic lymph nodes surrounding the bilateral recurrent laryngeal nerve and no evidence of metastasis to distant organs. Curative esophagectomy with three-field lymph node dissection was performed through thoracoscopic approach. Pathological examination of the resected specimens led to diagnosis of BSCE with invasion into the submucosal layer of the esophageal wall. Two years later, a solitary oval-shaped pulmonary lesion of approximately 10 mm was detected in the left lung. Wedge resection of the left upper lobe was performed via thoracoscopic approach. The postoperative course was uneventful. Histologically, the pulmonary lesion was diagnosed as metastatic BSCE. Follow-up indicated no recurrence 9 years after the initial surgery.

DISCUSSION

Surgical intervention was acceptable on this case of solitary pulmonary metastasis. However, data are lacking about the efficacy of pulmonary resection for metachronous pulmonary metastasis of BSCE because the postoperative outcome is usually poor. The efficacy of surgical intervention for metastatic lesions of BSCE is debatable and requires further examination.

CONCLUSION

Although the usefulness of surgical intervention for metastatic lesions from BSCE is controversial, the patients with metachronous solitary metastasis to the lung and without extrapulmonary metastasis would be good candidate for pulmonary resection.

1. Introduction

In Japan, squamous cell carcinoma is most common type of esophageal cancer.¹ Basaloid squamous cell carcinoma of the esophagus (BSCE) is an uncommon variant of squamous cell carcinoma of the esophagus (SCCE), and is extremely rare among esophageal malignancies. BSCE comprises approximately 0.1% of the esophageal carcinomas.¹ It is associated with a poor outcome after surgery because of its high proliferative activity, and high incidence of distant metastasis.^2,3 Many reports have described the prognosis of BSCE as worse than that of SCCE.^2,4,5 In this report, we described a case of long-term survival after successful treatment with pulmonary resection for metachronous pulmonary metastasis of BSCE.

2. Presentation of case

A 63-year-old woman, with a history of dysphagia for 4 months, was diagnosed with BSCE in the form of an elevated lesion of the lower thoracic esophagus by upper gastrointestinal fiberscopy (Fig. 1). Barium swallow showed an irregular shadow on the left side of the lower thoracic esophagus. Histological evaluation of biopsy specimens indicated poorly differentiated SCCE. Computed tomography (CT) revealed wall thickening in the lower thoracic esophagus, but no evidence of invasion to adjacent structures or metastasis to distant organs. Metastatic lymph nodes were detected in the surrounding bilateral recurrent laryngeal nerve. Curative esophagectomy with three-field lymph node dissection was performed via a thoracoscopic approach. A gastric tube was made by laparoscopic approach and used for esophageal substitute through postmediastinal route. Postoperatively, left recurrent laryngeal nerve palsy was observed.

Fig. 1.

Preoperative upper gastrointestinal fiberscopy showed an elevated lesion in the lower thoracic esophagus. Histological examination of biopsy specimens from this lesion were diagnosed as poorly differentiated squamous cell carcinoma of the esophagus.

Macroscopically, the resected specimen was an elevated lesion of the lower thoracic esophagus, measuring 3.0 cm × 2.0 cm (Fig. 2). Histologically, the cancer cells, which were similar to esophageal basal cells, had invaded into the submucosal layer of the esophageal wall, but no lymphatic or venous invasion was detected. The proximal and distal margins were cancer-free. Nests of basaloid cells of various sizes in a lobular configuration showed massive submucosal expansion (Fig. 3). Scant cytoplasm, round to oval nuclei and a high nuclear to cytoplasmic ratio were compatible with BSCE. Solitary lymph node metastasis was detected in the paragastric node. The patient was discharged from our hospital on postoperative day 42.

Fig. 2.

The resected specimen was an elevated lesion of the lower thoracic esophagus, measuring 3.0 cm × 2.0 cm.

Fig. 3.

Cancer cells, similar to basal cells of the esophagus, invading into the submucosal layer of the esophageal wall. No evidence of lymphatic or venous invasion was observed. Cancer nests of basaloid cells in a lobular configuration and massive submucosal expansion are visible.

Two years later, a solitary oval-shaped pulmonary lesion of approximately 10 mm in size was detected in the left lung on chest CT (Fig. 4). Tumor markers including the SCC antigen and carcinoembryonic antigens were within normal limits. Although systemic chemotherapy with combined with 5-fluorouracil (5-FU) and cisplatin (CDDP) was offered initially, the patient rejected this treatment. Wedge resection of the upper lobe of the left lung was therefore performed via thoracoscopic approach. No pleural dissemination was observed intraoperatively. The postoperative course was uneventful. Histologically, the pulmonary lesion was diagnosed as metastatic BSCE (Fig. 5). No adjuvant therapy was administered after pulmonary resection. The patient was discharged from our hospital on postoperative day 10. The patient is doing well without any recurrence 9 years after first operation.

Fig. 4.

Chest computed tomography 2 years postoperatively showed a solitary oval pulmonary lesion of approximately 10 mm in the left lung.

Fig. 5.

Histological evaluation of the pulmonary lesion led to diagnosis of metastasis of basaloid squamous cell carcinoma of the esophagus.

3. Discussion

In Japan, many cases of esophageal cancer are diagnosed as squamous cell carcinoma; other types of malignancies are rare.¹ BSCE has been thought to comprise approximately 0.1% of all esophageal carcinomas, according to a comprehensive registry of esophageal cancers in Japan.¹ However, considering recent advancements in the histological recognition of this type of tumor, the true incidence of BSCE is still uncertain.^6,4 Upper gastrointestinal fiberscopy with biopsy is the most commonly used method of diagnosis for the esophageal cancer prior to treatment. On endoscopic examination, BSCE is characterized as a protruding or submucosal tumor-like lesion, and the tumor was covered with normal mucosa at superficial type.⁷ Therefore, BSCE is difficult to diagnose by biopsy. The rate of correct preoperative diagnosis of BSCE has been reported to be <10%.⁵

The prognosis of BSCE has been reported as worse compared to that of SCCE, because of its high incidence of distant metastasis.^3,8 Saito et al. suggested that higher levels of cyclin D1 and lower expression of E-cadherin in BSCE than those in SCCE may correlate with high biological malignancy and a poor prognosis in patients with BSCE.⁹ On the other hand, Chen reported that the prognosis of BSCE was significantly poorer than that of well-differentiated SCCE, but was similar to that of moderately or poorly differentiated SCCE.⁵

Standard treatment for BSCE has not yet been established, because of its low incidence. At present, the treatment options for BSCE are similar to those for typical SCCE, because of the difficulties of correct pretreatment diagnosis.⁹ The benefits and usefulness of combined chemotherapy using 5-FU and CDDP for SCCE have been well documented.¹⁰ However, the efficacy of this combined therapy has not been investigated in BSCE. Koide et al.¹¹ reported two cases of BSCE of the esophagus treated by preoperative chemotherapy using 5-FU and CDDP. Follow-up in one case indicated no recurrence 38 months after chemotherapy. Shibata et al.¹² reported a case of recurrent BSCE successfully treated by combination chemotherapy using 5-FU and CDDP. These reports suggested usefulness of combination chemotherapy for BSCE. On the other hand, in an analysis of the activities of the 5-FU related enzymes, such as thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD) and orotate phosphoribosyl transferase (OPRT), in esophageal cancer tissue, the TS activity in BSCE was significantly higher than that in SCCE.¹³ However, no difference in DPD or OPRT was observed between these types of tumor. These results suggested that BSCE is more resistance to 5-FU than in SCCE. Because BSCE is a rare malignancy among esophageal carcinoma, comparison of the efficiency of chemotherapy regimens between BSCE and SCCE is difficult. Studies of a large sample are required to establish the role of combination chemotherapy in treatment of BSCE.

Esophageal cancer is known to be a lethal disease. Even after extended radical esophagectomy with three-field lymph node dissection, 40–50% of patients develop recurrent disease.^14,15 Recurrent disease after esophagectomy may be locoregional and/or hematogenous. Common sites of hematogenous recurrence include lung, liver and bone. Nakagawa et al.¹⁶ reported shorter disease-free intervals and median survival time in patients with hematogenous recurrence than in patients with locoregional recurrence. Nonsurgical treatments, such as systemic chemotherapy, are usually indicated for patients with hematogenous recurrence because it is widely regarded as a systemic disease. However, some reports have described the benefits of surgical treatment for pulmonary metastasis from esophageal cancer.^17,18 In these reports, patients with solitary pulmonary metastasis and no extrapulmonary metastasis were good candidates for pulmonary resection. In the case reported here, solitary pulmonary metastasis was detected and the patient's systemic condition was stable enough to withstand surgical intervention. However, data are lacking about the efficacy of pulmonary resection for metachronous pulmonary metastasis of BSCE because the postoperative outcome is usually poor. The efficacy of surgical intervention for metastatic lesions of BSCE is debatable and requires further examination.

4. Conclusions

We reported the case of a 63-year-old female with BSCE in whom solitary metachronous pulmonary metastasis was diagnosed 2 years after esophagectomy. In this case, the metastatic lesion was successfully treated by surgical intervention. However, examination of more cases is required to ascertain the role of pulmonary resection in treatment of pulmonary metastasis of BSCE, because the incidence of this disease is low and no standard treatment options have been established.

Conflict of interest

The authors declare that they have no competing interests.

Funding

None.

Ethical approval

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Author contribution

MT conceived the study, acquired patient data and drafted the manuscript. KY and KS critically reviewed the manuscript. YF was a major contributor in evaluating pathologic aspect of the manuscript. M. Takii was a major contributor in editing and revising the manuscript. All authors read and reviewed the final manuscript.