Endoscopic ultrasound elastography in the diagnosis of incidental malignant mesothelioma.

A 32-year-old female was referred to our institution for endoscopic ultrasound (EUS) evaluation due to a weight loss history (10 kg in 2 months) and serum carcinoembryonic antigen elevation (100 ng/mL). Physical examination was normal. Previously test including thorax and abdominal CT, upper and lower endoscopy, and capsule endoscopy were normal. EUS showed one round, well-delimited, black lymph node near to the aorta and another one with similar characteristics, but heterogeneous (black-white) near to the esophagus. EUS-elastography was performed showing a hard tissue (blue color) with a quantitative strain ratio (SR) of 131.1 [Figure 1] and the second one with a green-blue color pattern with a quantitative SR of 6.85, the first one being suspected for malignancy. EUS fine-needle aspiration (EUS-FNA) was performed and histopathology showed a mesothelioma [Figure 2].

Figure 1

Radial EUS scanning view of the thoracic lymph node near to the aorta. EUS-elastography showed a totally blue pattern with SR 131.1. EUS: Endoscopic ultrasound

Figure 2

Histopathology showing mesothelioma

Mesothelioma is a rare malignant disease that develops from cells of the mesothelium. The most common anatomical site for mesothelioma is the pleura; but peritoneum, pericardium, and tunica vaginal is could develop these tumors.[1] Despite treatment, this kind of tumors have poor prognosis. Diagnosis is performed by clinical symptoms: Weight loss, chest pain, and dyspnea due to pleural effusion. Radiological imaging as CT, X-ray, and thoracoscopy with biopsies or cytological analysis of the pleural effusion help to confirm the diagnosis. However, in some incidental cases as this one when the disease is beginning, such tests are not enough.[2] EUS-FNA had demonstrated its utility in the diagnosis of mediastinal masses including mesothelioma.[2] Moreover, EUS-elastography had demonstrated that could help to determine which lymph nodes are suspected for malignancy based on the principle that malignant tissue are hard (blue pattern) associated to quantitative SR >7.5.[34] This incidental case presented as an image showed the utility of EUS-elastography and that mesothelioma tumors are very hard lesions with elastography SR >100.