Pulmonary Sclerosing Pneumocytoma: A Case Revealed During 8-year of Follow-up with CT Imaging

Abstract

Pulmonary sclerosing pneumocytoma (PSP) is a rare, benign tumor. Given the challenges of a bronchoscopic diagnosis, surgery is performed during the early stages of the disease. Therefore, little is known about the growth pattern of PSP. This case of PSP was not diagnosed despite bronchoscopy, resulting in lung resection eight years after the anomaly was first identified on computed tomography (CT). This report compares the long-term follow-up of CT and pathological findings and discusses the difficulty in making a diagnosis using a bronchoscopic forceps biopsy to aid in future PSP diagnoses and treatment planning.

Keywords: CT imaging; bronchoscopy; lung tumor; preoperative diagnosis; pulmonary sclerosing pneumocytoma.

Figure 1.

(A) 8 years ago (mediastinum), (B) 8 years ago (lung); the nodule was about 18×19 mm, and the surrounding bronchi were not compressed (white arrow), (C) Before surgery (mediastinum), (D) before surgery (lung); a 25×21 mm rounded nodule with small calcifications on the medial side of the left lower lobe. Bronchi of the surrounding area were compressed by the nodule (white arrow).

Figure 2.

(A) CT scan showing the bronchus near the mass compressed by the mass (arrowhead). (B) Macroscopic section showing a yellowish-white solid tumor with a well-defined border and a hemorrhagic component. (C) Low-magnification photomicrograph showing a well-defined solid tumor. The tumor did not destroy the surrounding lung structure, suggesting expansive growth. A close examination of the border between the tumor and surrounding lung tissue showed that the tumor was adjacent to the bronchus (asterisk). In this image, the interlobular septum (arrowheads) lies between the tumor and bronchus.

Figure 3.

(A) Hematoxylin Eosin stain, middle magnification: papillary growth pattern with surface cuboidal (yellow arrow) and stromal cells (white arrow). (B) Hematoxylin Eosin stain, middle magnification: solid growth pattern with cuboidal cells. (C) EMA was positive for surface cells and partial stromal cells, middle magnification. (D) Napsin A was positive for surface cells only, middle magnification. (E) TTF1 was positive for both surface and stromal cells, middle magnification.