PMC6198119_01
CT (computed tomography) scan of chest and EBUS (endobronchial ultrasound) findings. (A, B) Contrast-enhanced chest CT (computed tomography) shows a 20 mm irregularly shaped peripheral nodule in the right lower lobe and several bilateral mediastinal lymph nodes. (C, D) After treatment with gefitinib for 1 month, the primary lesion is smaller in size at 10 mm, but the lymphadenopathies remain unchanged. (E) On PET (positron emission tomography), the lymph nodes have high FDG (18F-fluoro-2-deoxyglucose) uptake, with SUV max (maximum standardized uptake value) of 6.7. (F) EBUS (endobronchial ultrasound) shows several enlarged, homogeneous lymph nodes (asterisk) without coalescent or aberrant vessels in stations 4L and 4R.
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After a month of taking gefitinib (250 mg) daily, chest computed tomography (CT) showed a dramatic decrease in the size of the primary lesion from 20 to 10 mm, but the lymphadenopathy persisted (Fig. 1A-D). CEA, 4.3 ng/mL; SLX, 36 U/mL; soluble IL-2 receptor, 349 U/mL; angiotensin-converting enzyme, 14.6 U/mL; and Ca, 9.2 mg/dL. Chest X-ray and contrast-enhanced CT showed an irregularly shaped peripheral nodule in the right lower lobe and several bilateral mediastinal LNs with high FDG uptake on PET (Fig. 1E). During EBUS-TBNA, the EBUS images showed homogeneous echogenicity and straight vessels in the LNs (Fig. 1F).
Specimen detail from EBUS-TBNA (endobronchial ultrasound-guided transbronchial needle aspiration) and operation. (A) Photomicrographs of the EBUS-TBNA (endobronchial ultrasound-guided transbronchial needle aspiration) lymph node specimens show tiny crushed tissue fragments with incorporated spindle cells, which histologically imply epithelioid cell granuloma. (B) Small round bodies is detected by PAB antibody (a specific monoclonal antibody against Propionibacterium acnes), which imply immunopositivity for Propionibacterium acnes. (C) Gross examination of the cut surface of the resected lung shows a light brown-colored tumor (white arrowheads). (D) The tumor is histologically diagnosed as papillary adenocarcinoma surrounded by marked fibrosis that suggested a therapeutic effect for cancer. (E) Histologic examination of the simultaneously dissected lymph nodes shows abundant non-caseous epithelioid cell granulomas with Langerhans-type giant cells and several Hamazaki-Wesenberg bodies (inset), but there is no fibrosis or foamy macrophages, both of which histologically indicated the therapeutic effect. (F) The lymph nodes contain small round bodies detected by the PAB antibody.
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The pathological findings showed several non-caseating epithelioid granulomas, without tumor cells (Fig. 2A). Moreover, the PAB antibody detected small round bodies in the LNs (Fig. 2B), indicating that the lymphadenopathy was caused by sarcoidosis, not sarcoid reaction. Following the discontinuation of the gefitinib course, right lower lobectomy and regional lymphadenectomy were immediately performed (Fig. 2C). The final pathologic diagnosis was stage IA lung adenocarcinoma with sarcoidosis of the mediastinal LNs (Fig. 2D-F).