CASE OF THE MONTH
Cryptococcus neoformans
This 68 year old male underwent upper lobectomy of the right lung. Histologic sections demonstrated metastatic renal cell carcinoma, clear cell type, measuring 4.5 x 2.5 x 1.7 centimeters, involving the upper lobe of the right lung. The pulmonary parenchymal surgical margin of resection and the bronchial surgical margin of resection were free of neoplasm. The metastatic renal cell carcinoma, clear cell type, did not involve the visceral pleural surface.
In addition, there was evidence of pulmonary cryptococcal pneumonitis (pulmonary cryptococcosis) demonstrating a granulomatous multinucleated histiocytic giant cell reaction to mucicarmine positive encapsulated, GMS positive pleomorphic cryptococcal budding yeast forms, with chronic inflammation and interstitial stromal collagenized fibrosis.The GMS stain (adequate control) was positive for fungal yeast forms, morphologically that of Cryptococcus neoformans. The mucicarmine stain (adequate control) was positive for the presence of mucicarmine positive capsules of the fungal yeast forms, morphologicaly that of Cryptococcus neoformans.
