AN UNSUSPECTING CASE OF CENTRILOBULAR PULMONARY NODULES

Abstract

SESSION TITLE: Wednesday Medical Student/Resident Case Report Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: 10/23/2019 09:45 AM - 10:45 AM INTRODUCTION: The incidence of IV drug use continues to rise with a concomitant rise in IV drug related complications. It is not uncommon for this population to inject medicine intended for oral use, which can lead to deposition of foreign material causing granulomas. Adequate tissue sampling with a high index of suspicion are key in forming this diagnosis. CASE PRESENTATION: 41 yo female with Crohn’s disease presents with progressively worsening dyspnea. She has received total parenteral nutrition via a Hickman catheter over the past 9 years since undergoing bowel resection and ileostomy. Prior to her acute presentation she underwent outpatient CT/PET chest imaging demonstrating tiny hypermetabolic bibasilar ground-glass centrilobular nodules. On presentation, blood cultures performed were consistent with poylmicrobial bacteremia with a repeat chest CT now demonstrating diffuse bilateral subsolid micronodules in a centrilobular distribution which had increased in number and size. Diagnostic flexible bronchoscopy was inconclusive and ultimately transbronchial lung cryobiopsy (TBLCB) was performed. Pathology revealed non-necrotizing granulomas with inclusions of talc and other foreign material. After initially denying, the patient did admit to intravenous injection of her oral dilaudid. DISCUSSION: Talc functions as a structural binder in many oral tablets including opioids. Pulmonary talcosis is seen in IV drug abusers who inject drugs intended for oral administration2. The lungs are the first capillaries exposed to intravascularly administered foreign material and thus house the majority of this deposition4. When deposited in tissue, talc induces an inflammatory non-necrotizing granulomatous reaction within the lung interstitium leading to interstitial pulmonary fibrosis and intravascular talcosis within the pulmonary vasculature. Tissue biopsy is required to establish the diagnosis and can be challenging as the tissue sample can miss the area of deposition. TBLCB is a relatively novel technique offering an alternative less invasive diagnostic modality to surgical options. Cryobiopsy specimens increase the sensitivity of conventional transbronchial forceps biopsy techniques through larger and more preserved tissue sampling5. The reporting pathologist in this case made mention that the diagnosis may not have been apparent without this sampling technique. CONCLUSIONS: The management of TALC induced granulomas is not well understood. Accurate diagnosis will allow for further research into treatment options. TBLCB is a relatively new tool in our armamentarium for diagnostic bronchoscopy that can potentially avoid more invasive open surgical diagnostic approaches. Reference #1: Lentz, R. Transbronchial cryobiopsy for diffuse parenchymal lung disease: a state-of-the-art review of procedural techniques, current evidence, and future challenges. Journal of Thoracic disease. 2017 Jul; 9(7): 2186–2203. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5542930/ Reference #2: Kazerooni, E. High-resolution CT of the lungs. American Journal of Roentgenology. 2001;177 (3): 501-19. https://www.ajronline.org/doi/full/10.2214/ajr.177.3.1770501 Reference #3: Matrosovich, E. Dyspnea following IV drug use. Respiratory Medicine Case Reports. Volume 20, 2017, pages 192-194. https://www.sciencedirect.com/science/article/pii/S2213007116301770?via%3Dihub DISCLOSURES: No relevant relationships by Mohammad Beizaeipour, source=Web Response No relevant relationships by Ismael Matus, source=Web Response No relevant relationships by Jonathan Norton, source=Web Response No relevant relationships by Haroon Raja, source=Web Response