SHM Converge Scientific Abstract ePoster Gallery-Black Pleural Effusion

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A 36-year-old man presented with one month of fevers, night sweats, low back pain, and an enlarging pigmented back lesion. Exam showed left axillary lymphadenopathy, a 10 cm irregular pigmented lesion, and decreased breath sounds at both lung bases. Diagnostic right thoracentesis yielded 50 mL of black pleural fluid. Analysis showed an exudative effusion with a very high nucleated cell count, and 85% of the cells were melanoma cells. Cytopathology and molecular testing confirmed metastatic melanoma with a BRAF p.V600 mutation, and he was started on targeted therapy with binimetinib and encorafenib.<br /><br />This case highlights that black pleural effusion is a rare but important finding that should substantially narrow the differential diagnosis. The main causes include malignancy—especially melanoma—fungal infections such as Aspergillus niger and Rhizopus oryzae, pancreaticopleural fistula, hemolysis after intrapleural bleeding, and charcoal-containing empyema. In melanoma, the dark color is due to melanin produced by tumor cells.<br /><br />The case also illustrates the value of thoracentesis in evaluating new pleural effusions. Pleural fluid cytology has only moderate sensitivity for malignancy overall, but the unusual black color in this patient pointed strongly toward melanoma and allowed for a rapid diagnosis without more invasive biopsy.

Asset Subtitle

Li-Kheng Ngov

Meta Tag

Author List Henry R. Kramer, Li-Kheng Ngov

Category Clinical Vignettes

Concept Thoracentesis

Concept Pleural Effusion

Concept Black Pleural Effusion

Concept Metastatic Melanoma

Concept Pleural Fluid Analysis

Distinguished Non-Finalist

Presenter Organization University of Colorado

Presenting Author Li-Kheng Ngov

Track Adult

Keywords

black pleural effusion

melanoma

thoracentesis

exudative effusion

BRAF mutation

binimetinib

encorafenib

pleural fluid cytology

metastatic melanoma

pigmented lesion

Thoracentesis

Pleural Effusion

Black Pleural Effusion

Metastatic Melanoma

Pleural Fluid Analysis