title: Blizzard Sign as a specific endobronchial ultrasound image for ground glass opacity: A case report.
abstract: We report a case of lung adenocarcinoma presenting as pure ground glass opacity (GGO) and diagnosed by bronchoscopy with the use endobronchial ultrasound with a guide sheath (EBUS-GS). The lesion was indistinguishable by real-time fluoroscopy but simultaneous endobronchial ultrasound scanning of the involved lung segment showed a hyperechoic shadow that was subtly more intense than a typical snowstorm appearance when scanning normal alveolar tissue. Transbronchial biopsy from this area revealed adenocarcinoma with lepidic growth. On hindsight, it was the aforementioned ultrasound pattern that helped us decide the sampling site for EBUS-GS guided TBB when fluoroscopy was equivocal. We hypothesize that this pattern is specific for GGO and we name it the Blizzard Sign.
authors.affiliation: Department of Endoscopy, Respiratory Endoscopy Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Sasada
authors.affiliation: Department of Endoscopy, Respiratory Endoscopy Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Izumo
authors.affiliation: Department of Endoscopy, Respiratory Endoscopy Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: Christine
authors.initials: C
authors.lastname: Chavez
authors.affiliation: Department of Endoscopy, Respiratory Endoscopy Division, National Cancer Center Hospital, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan.
authors.forename: Takaaki
authors.initials: T
authors.lastname: Tsuchida
keywords: AIS, adenocarcinoma in situ; Blizzard Sign; CT, computed tomography; EBUS, endobronchial ultrasound; EBUS-GS, endobronchial ultrasound with a guide sheath; Endobronchial ultrasound with a guide sheath; GGO, ground glass opacity; Ground glass opacity; MIA, minimally invasive adenocarcinoma; PPL, peripheral pulmonary lesion; Peripheral pulmonary lesion; TBB, transbronchial biopsy