대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Diagnosis

Sarcoidosis with necrotizing sarcoid granulomatosis (NSG) pattern

Radiologic Findings

Contrast-enhanced chest CT images (Figure 1) show lobulated pulmonary nodules with peribronchovascular distribution (A, B) and areas of low attenuation representing necrosis (arrows in C, D).
Afluorine 18-fluorodeoxyglucose positron emission tomography-computed tomography scan (Figure 2) shows avid uptakes in the nodules in the right middle lobe and left lower lobe (maximum standardized uptake values: 10.0 and 8.5, respectively).


The patient underwent a video-assisted thoracoscopic surgery with a lung biopsy of nodules in the left lower lobe. Histopathological evaluation revealed multiple inflammatory nodules with confluent granulomas and large zones of necrosis. The granulomas were composed of epithelioid cells and multinucleated giant cells. Vasculitis with lymphoplasmacytic infiltration was also well seen. The histopathologic diagnosis was sarcoidosis with a necrotizing sarcoid granulomatosis pattern.

Brief Review

Necrotizing sarcoid granulomatosis (NSG) is characterized by findings of sarcoid-like granulomas, vasculitis, and a variable degree of necrosis. Recently, it is accepted as a more convincing idea that NSG is a variant of sarcoidosis with extensive infarct-like necrosis. Therefore, the term ��sarcoidosis with NSG pattern�� is used instead of NSG to reflect the clinical entity of nodular sarcoidosis.
Sarcoidosis with NSG pattern can be easily misdiagnosed as pulmonary malignancy or other pulmonary granulomatous diseases due to their similar radiologic findings and nonspecific clinical presentation. It occurs more frequently in women than men with a variable prevalence of extrapulmonary involvement such as eyes, skin, and nerve systems. The pattern of multiple lung nodules is the most common radiologic presentation, followed by a solitary nodule or mass. Thoracic lymphadenopathy and cavitation of nodules are often observed.
The most commonly used treatment for sarcoidosis with NSG pattern is systemic steroid therapy. Unlike other systemic vasculitis or malignancy, a good response with systemic corticosteroid treatment is expected. The disease also can show spontaneous regression. The overall prognosis of sarcoidosis with NSG pattern is favorable. Therefore, the minimally invasive diagnostic procedure can be considered for better patient management.

References

1. Karpathiou G, Batistatous A, Boglou P, et al. Necrotizing sarcoid granulomatosis: a distinctive form of pulmonary granulomatous disease. Clin Respir J 2018l12:1313-9.
2. Franquet T, Franks TK, Galvin JR, et al. Non-infectious granulomatous lung disease: imaging findings with pathologic correlation. Korean J Radiol 2021;22:1416-35.
3. Giraudo C, Nannini N, Balestro E, et al. Necrotizing sarcoid granulomatosis with an uncommon manifestation: clinicopathological features and review of literature. Respir Care 2014;59:e132-6.
4. Jun Hyeok K, Bo Da N, Jung Hwa H, et al. Necrotizing sarcoid granulomatosis simulating pulmonary malignancy: a case report. Medicine 2021;10:100(49):e28208.

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