Fruiting Bodies of Aspergillus in a Cavitary Lung Mass: A Rare Finding on Fine Needle Aspiration

Endobronchial ultrasound (EBUS) guided fine needle aspiration is a modality for diagnosing lung nodules as well as fungal organisms. One of the most frequently isolated fungal organisms from immunocompromised patients or immunocompetent patients with severe COPD is Aspergillus spp., which is characterized by septate hyphae with progressive dichotomous branching. However, this finding is not entirely specific to Aspergillus spp. since it can be seen in non-Aspergillus fungi. Nonetheless, the presence of fruiting bodies, background inflammation, and in correlation with the clinical and radiologic findings are supportive of Aspergillus infection. This case report describes a 73-year-old male smoker with severe COPD who presented with multiple lung nodules and hilar lymphadenopathy. An EBUS guided fine needle aspiration of the largest left lung cavitary nodule showed the presence of uniformly sized, septate hyphae with progressive dichotomous branching. There were randomly distributed fruiting bodies composed of a smooth stalk, a swollen vesicle at the terminal end of the stalk, and a single row of phialides occupying the upper two-thirds of the vesicle. The background showed marked acute inflammation and singly dispersed conidia (spores). The GMS stain highlighted the presence of fruiting bodies, dichotomous branching septate hyphae, and singly dispersed conidia. The Fungal PCR result confirmed the presence of Aspergillus fumigatus. Hence, the presence of fruiting bodies is extremely helpful in the identification of the Aspergillus spp. over the other non-Aspergillus fungi. While species identification is often performed in culture, the cytomorphology of the fruiting body could favor Aspergillus spp., which could facilitate prompt medical management.