대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Squamous cell carcinoma, keratinizing, with lepidic growth pattern

Radiologic Findings

Fig 1. Initial non-contrast chest CT revealed a 2‑cm pure ground‑glass opacity in the right lower lobe, without significant solid components. According to Lung‑RADS criteria, the lesion was categorized as Lung‑RADS 2, and annual follow‑up was recommended.
Fig 2. Follow‑up CT obtained 12 months later demonstrated significant interval growth to 4 cm, while the lesion remained a pure GGO. Due to the marked size increase, the lesion was reclassified as Lung‑RADS 4A, and surgical resection was performed.

Brief Review

Pure ground‑glass opacity (GGO) lesions are most commonly associated with adenocarcinoma spectrum tumors, including adenocarcinoma in situ, minimally invasive adenocarcinoma, and lepidic‑predominant adenocarcinoma. In contrast, squamous cell carcinoma (SCC) rarely presents as a GGO lesion, and reports of SCC with a lepidic growth pattern are extremely uncommon. This case highlights that SCC can occasionally manifest as pure GGO, particularly when they exhibit a lepidic growth pattern. Therefore, significant interval growth of a pure GGO, even when initially categorized as low‑risk, warrants timely diagnostic evaluation.

References

1. Sakaizawa T, Yoshizawa A, Nishimura H, Arimura T, Kobayashi N, Ozawa K, Asaka S, Yoshida K, Hirai K, Hosaka N. A Case of Pulmonary Squamous Cell Carcinoma Revealed Ground Glass Opacity on Computed Tomography. J Thorac Oncol. 2015 Aug;10(8):1229-30. doi: 10.1097/JTO.0000000000000462. PMID: 26200279.
2. Terada Y, Sato M, Abe H, Kuwano H, Nagayama K, Nitadori JI, Anraku M, Nakajima J. Squamous cell carcinoma of the lung showing a ground glass nodule on high-resolution computed tomography associated with pneumoconiosis: a case report. Surg Case Rep. 2017 Sep 29;3(1):107. doi: 10.1186/s40792-017-0384-1. PMID: 28963659; PMCID: PMC5622012.

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