Vaszar, Laszlo

Transbronchial cryobiopsies (CB) are increasingly replacing surgical biopsies (video-assisted thoracoscopic/VATS biopsies) for diagnosing diffuse parenchymal lung disease (interstitial lung disease, ILD), but there is very little guidance for pathologists on CB interpretation. Here we propose a fairly simple approach. First, if the diagnosis can be made on a traditional forceps biopsy, it can be made on a cryobiopsy. Many diseases with specific features will fall into this category (eg, sarcoidosis or Langerhans cell histiocytosis). More problematic are patterns such as usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia (NSIP), in which low-power architecture is the key to diagnosis. In this circumstance, an adequate sample is crucial to look for features such as fibroblast foci, because a combination of fibroblast foci plus any patchy old fibrosis, fibrotic architectural remodeling, or honeycombing, allows a diagnosis of a UIP pattern. However, in most instances, CB will not separate the UIP patterns seen in idiopathic pulmonary fibrosis, fibrotic hypersensitivity pneumonitis, or connective tissue disease-interstitial lung disease (CTD-ILD), although giant cells/granulomas (uncommon findings) in this setting favor fibrotic hypersensitivity pneumonitis. Fibroblast foci can be difficult to differentiate from organizing pneumonia (OP), but granulation tissue plugs clearly in airspaces favor OP. Absent fibroblast foci, patchy old fibrosis, architectural distortion, and honeycombing by themselves do not allow a specific diagnosis. NSIP in CB microscopically looks like NSIP in VATS biopsies, and the presence of an NSIP or an NSIP+OP pattern is typical of CTD-ILD. All the above diagnoses require correlation with clinical and radiologic findings.

The use of venovenous extracorporeal membrane oxygenation (VV-ECMO) has traditionally been limited to a narrow set of clinical circumstances, such as acute hypoxic respiratory failure, submassive pulmonary embolism, and cardiopulmonary collapse. Within the pediatric population, there have been cases of VV-ECMO in the context of extrinsic airway compression by a mediastinal mass, typically in the setting of either a lymphoma or germ cell tumors. However, the use of VV-ECMO for adults with extrinsic airway compression is comparatively limited. More specifically, VV-ECMO has been used as a bridge for tracheal reconstruction in both children and adults. Although, it has not been used in adults in the context of palliative endobronchial stent placement. We present a case of a 49-year-old woman with refractory multiple myeloma and extramedullary plasmacytoma presenting with acute hypoxic respiratory failure from extrinsic airway compression by a mediastinal plasmacytoma. We were able to use VV-ECMO to assist with endobronchial stent placement, followed by radiation therapy, and ultimately hospital discharge. In this article, we also review the literature surrounding VV-ECMO for extrinsic airway compression.