대한흉부영상의학회 Korean Society of Thoracic Radiology

Discussion

Diagnosis With Brief Discussion

Courtesy

Asan Medical Center, Seoul Korea

Definitive Diagnosis

Diagnostic methods

Excisional biopsy

Gross pathology; a well defined grayish tan and fibrotic mass

Lung, wedge resection:

- Inflammatory mass - like lesions, consistent with plasma cell granulomas

- No evidence of malignancy

Discussion

Brief Discussion

Plasma cell granuloma (Inflammatory pseudotumor)

-Quansineoplastic lesion consisting of inflammatory cells and myofibroblastic spindle cells

-Lung, orbit, nearly every site in the body

-Pathogenesis: Unknown

1) Low grade fibrosarcoma

2) Inflammation following minor trauma or surgery

3) Secondary to infection

Pulmonary inflammatory pseudotumor

Most common primary lung mass in children

No sex predilection, peak age in second decade

Clinical manifestation: Usually asymptomatic, cough, fever, dyspnea, and hemoptysis

20%: antecedent pulmonary infection

Three histologic types

1) Organizing pneumonia pattern: characterized by airways filled with plump fibroblasts and foamy histiocytes and parenchyma replaced with a mixture of histiocytes, mononuclear cells, and fibroblasts

2) Fibrous histiocytic pattern: spindle-shaped myofibroblasts arranged in whorls

3) Lymphohistocytic pattern: mixture of lymphocytes and plasma cells with only minimal fibrous connective tissue


Radiologic findings

-CXR: solitary, peripheral, sharply circumscribed, lobulated mass

-CT: Variable, nonspecific heterogeneous attenuation and enhancement

-MR: Intermediate signal intensity on T1WI, high SI on T2WI

-Multiple lesions: 5%

Treatment: Surgical resection, high-dose steroid, irradiation, chemotherapeutic agent

Prognosis: Local recurrence (25%), rare distant metastasis and spontaneous remission


Radiologic differential diagnosis

-Solitary pulmonary nodule: primary or secondary neoplasm, hamartoma, chondroma, hemangioma, granuloma. Pulmonary sequestration

-Multiple nodules: metastasis

Reference

Plasma cell granuloma (Inflammatory pseudotumor)

-Quansineoplastic lesion consisting of inflammatory cells and myofibroblastic spindle cells

-Lung, orbit, nearly every site in the body

-Pathogenesis: Unknown

1) Low grade fibrosarcoma

2) Inflammation following minor trauma or surgery

3) Secondary to infection

Pulmonary inflammatory pseudotumor

Most common primary lung mass in children

No sex predilection, peak age in second decade

Clinical manifestation: Usually asymptomatic, cough, fever, dyspnea, and hemoptysis

20%: antecedent pulmonary infection

Three histologic types

1) Organizing pneumonia pattern: characterized by airways filled with plump fibroblasts and foamy histiocytes and parenchyma replaced with a mixture of histiocytes, mononuclear cells, and fibroblasts

2) Fibrous histiocytic pattern: spindle-shaped myofibroblasts arranged in whorls

3) Lymphohistocytic pattern: mixture of lymphocytes and plasma cells with only minimal fibrous connective tissue


Radiologic findings

-CXR: solitary, peripheral, sharply circumscribed, lobulated mass

-CT: Variable, nonspecific heterogeneous attenuation and enhancement

-MR: Intermediate signal intensity on T1WI, high SI on T2WI

-Multiple lesions: 5%

Treatment: Surgical resection, high-dose steroid, irradiation, chemotherapeutic agent

Prognosis: Local recurrence (25%), rare distant metastasis and spontaneous remission


Radiologic differential diagnosis

-Solitary pulmonary nodule: primary or secondary neoplasm, hamartoma, chondroma, hemangioma, granuloma. Pulmonary sequestration

-Multiple nodules: metastasis

Keywords

Lung, Non-infectious inflammation,