Collision Tumor of the Esophagus: A Report of Five Cases
Collision tumors are rare neoplasms characterized by the coexistence of two distinct cell populations that develop in close proximity to each other with minimal or no intermingling. These tumors are most commonly found in the lungs, cranium, rectum, liver, uterus, bladder, and testis. However, esophageal collision tumors are exceedingly rare, and their biologic behavior remains poorly understood. This report presents five cases of esophageal collision tumors, providing detailed insights into their clinicopathologic characteristics, treatment outcomes, and prognostic implications.
Case 1 involved a 72-year-old man who presented with epigastric pain and dysphagia for three months. A provisional diagnosis of adenocarcinoma of the gastroesophageal junction was made, leading to an open trans-thoracic partial esophagogastrectomy with standard lymphadenectomy. Histologic examination revealed a poorly differentiated adenocarcinoma adjacent to a moderately differentiated squamous-cell carcinoma, colliding without intermingling. The patient did not receive adjuvant therapy and experienced a relapse of dysphagia four months post-surgery, ultimately succumbing to tumor recurrence 17 months after the initial diagnosis.
In Case 2, a 75-year-old man was admitted for a focal liver lesion discovered during a routine physical examination. Enhanced computed tomography revealed thickening and an enhanced lesion in the cardiac wall, along with swelling in a pericardial lymph node. The patient underwent proximal sub-total gastrectomy and left hepatic lobectomy. Pathologic examination identified an infiltrative malignant neoplasm comprising basal-like squamous-cell carcinoma and adenocarcinoma, with no transitional areas between the two. Metastatic adenocarcinoma in the left lobe of the liver was confirmed. Despite receiving adjuvant therapy for liver metastasis, the patient died of tumor recurrence four years and one month after diagnosis.
Case 3 featured a 62-year-old man with a three-month history of dysphagia. He underwent esophagogastrostomy with standard lymphadenectomy. Immunohistochemical staining revealed an infiltrative malignant neoplasm consisting of moderately differentiated squamous-cell carcinoma and small-cell carcinoma, with no merging at the tumor cell interface. Given the advanced stage, the patient received three courses of adjuvant chemotherapy. No recurrence was observed during six months of follow-up, but the patient died of tumor metastasis 13 months post-diagnosis.
Case 4 involved a 64-year-old woman hospitalized with a two-month history of a choking feeling and substernal chest pain. She underwent radical esophagectomy with intra-thoracic esophagogastric anastomosis. Microscopic examination of the resected tumor showed squamous-cell carcinoma and small-cell carcinoma. Immunostaining demonstrated strong and extensive staining of the squamous component with cytokeratin 34bE12 and p63, while the small cell component was positive for synaptophysin, chromogranin A, cluster of differentiation 56 (CD56), and thyroid transcription factor 1. Two months post-operation, computed tomography indicated enlarged mediastinal lymph nodes, prompting adjuvant radiotherapy. The patient died of tumor recurrence six years and six months after diagnosis.
Case 5 described a 57-year-old woman with a one-year history of belching and chest pain after swallowing for approximately one month. She underwent minimally invasive McKeown esophagectomy with extensive mediastinal and abdominal lymphadenectomy. Pathologic examination and immunohistochemistry confirmed the presence of small-cell carcinoma and squamous-cell carcinoma colliding in the middle of the esophagus. The squamous component was strongly and extensively stained with cytokeratin 34bE12 and p16, while the small cell component was positive for synaptophysin, chromogranin A, and CD56. The patient received four continuous courses of chemotherapy and showed no evidence of recurrence or metastasis four years post-surgery, currently living a normal life.
Collision tumors are challenging to diagnose and must be distinguished from composite tumors or primary synchronous carcinomas. Unlike composite tumors, which arise from the same neoplastic clonal proliferation, collision tumors are dual-origin tumors that grow in proximity until they become juxtaposed. Accurate diagnosis is crucial for individualized therapy and surveillance. Pre-operative diagnosis is often difficult, relying on endoscopic biopsy and observation of the sampled site. Multiple tumor biopsy sites can improve diagnostic efficacy, and molecular genetic analysis may be necessary if immunohistochemistry is inconclusive.
The etiology and oncogenic mechanisms of collision tumors remain unclear. Surgery is the primary treatment, but these tumors are generally aggressive with an unfavorable prognosis dependent on the tumor stage at diagnosis and the components involved. Post-surgical follow-up is essential, though evidence-based guidelines for adjuvant therapy and follow-up intervals are lacking. Further research is needed to explore the pathogenesis and optimal management of these rare tumors.
In conclusion, esophageal collision tumors are clinically challenging to distinguish from non-collision tumors and rarely diagnosed pre-operatively due to the absence of specific clinical or biologic features. This report provides comprehensive insights into the clinicopathologic characteristics and biologic behavior of esophageal collision tumors, emphasizing the need for increased attention to these rare neoplasms.
doi.org/10.1097/CM9.0000000000000982
Was this helpful?
0 / 0