EBUS‐FNA of a station seven lymph node: An unusual presentation of a young nonsmoker male with hemoptysis and subcarinal lymphadenopathy

Abstract

Endobronchial ultrasound-guided fine needle aspiration (EBUS-FNA) is a safe and minimally invasive bronchoscopic technique that allows both visualization and cytologic sampling with a high diagnostic yield in a patient with mediastinal lymphadenopathy. Besides the most common indication of staging for a patient with a primary lung carcinoma, EBUS-FNA can be used to identify benign infectious and noninfectious processes as well as lymphoma and malignancy of unknown primary. Triaging of procured specimen for diagnostic, prognostic, and therapeutic ancillary studies requires appropriate clinical information at the time of rapid on site evaluation (ROSE) of smears. This case report demonstrates a young, previously healthy nonsmoker presenting clinically with cough, hemoptysis, and a 1.7 cm enlarged subcarinal lymph node by imaging. EBUS-FNA obtained smears from the lymph node revealed a pleomorphic population of smaller cells with a low nuclear to cytoplasmic ratio and prominent nucleoli, and larger cells had nuclei with bizarre shapes, mitoses, multinucleation, enlarged nucleoli, and pigmentation in a background of lymphocytes. The cytomorphologic and immunohistochemical workup of this case confirmed the unexpected diagnosis of metastatic melanoma. This result was a complete surprise to the clinical team managing the patient and prompted a thorough clinical workup. Subcarinal lymphadenopathy with metastatic malignant melanoma as the cause is rare. This case report highlights how ROSE and appropriate triaging of specimen were crucial in appropriately working up this case. We also survey the literature to review the reported unusual presentations of metastatic melanoma.

Pitfalls in Respiratory Tract Cytopathology

“…Melanoma will often (though not alwayssee Fig. 9) have a greater degree of nuclear atypia and pigment in the cytoplasm of tumour cells, where present, should, at least focally, be finely divided [44]. A potential pigment contaminant to be aware of is metal alloy, thought to be created due to friction between the stylet and the needle in EBUS samples.…”

Use of cytological samples of metastatic melanoma for ancillary studies

“…A high diagnostic accuracy of FNA in the assessment of questionable or recurrent superficial lesions of metastatic melanoma with 97% sensitivity and 99% specificity has been reported in a systematic review and meta‐analysis . For deep‐seated metastases, image‐guided FNA samples obtained by computed tomography (CT), ultrasound (US), endoscopic ultrasound (EUS) and endobronchial ultrasound (EBUS) have become the main diagnostic modalities …”