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Título

Diagnosis by EUS of a late metastasis to the lung from a rectal adenocarcinoma

Resumo

INTRODUCTION
Accurate biopsy-based diagnosis of pulmonary lesions is crucial for define the histological type and adequate planning treatment. In patients with intrapulmonary tumors located near the esophagus, transesophageal endoscopic ultrasound-guided fine-needle aspiration (TEUS-FNA) may provide a valuable minimally invasive alternative.
CASE REPORT
A 71-year-old male presented with rectal bleeding and was diagnosed with a moderately differentiated adenocarcinoma in the rectum. That time, there was no evident distant metastasis. He underwent rectosigmoidectomy in 2019, after neoadjuvant therapy. The surgical specimen showed presence of, budding but without lymphatic, vascular and neural invasion. Staging was ypT2ypN0.
The patient continued to be followed up, and in 2020, the emergence of two small nodules at the apex of the right lung. In June 2022, it was noticed that one of the nodules had increased in size. Due to its proximity to the esophagus, a transesophageal EUS puncture was requested.
With the linear echoendoscope positioned 23 cm from the upper dental arch, a hypoechoic lesion measuring 12mm x 15mm was visualized in the upper lobe of the right lung, near the esophageal wall, and was punctured with a 22GA standard FNA needle. The procedure had no complications and the patient was discharged in the same day. The pathological report poorly differentiated carcinoma and extensive necrosis. Immunohistochemistry was positive for CDX-2; while CK-5, napsin-A, p63 and ITF-1 were negatives. This immunophenotype profile was compatible with colorectal metastasis.
DISCUSSION
Histology with immunohistochemistry is necessary to differentiate primary from secondary lung lesions. Bronchoscopy and endobronchial ultrasound (EBUS) have raised the diagnosis of pulmonary masses. However, these tests may fail in approximately 30% of patients with centralized lung lesions. These patients are frequently referred for CT-guided biopsy, thoracoscopy, mediastinoscopy, or thoracotomy. These procedures are invasive, often requiring general anesthesia and with considerable complication rates. In this context, TEUS-FNA has been a minimally invasive alternative for the diagnosis of lung lesions close to the esophagus and some mediastinal lymph nodes.
CONCLUSION
This case shows that TEUS-FNA can provide accurate diagnostic late metastasis to the lung from a rectal adenocarcinoma.