SARCOIDOSIS
Sarcoidosis is characterized by noncaseating epithelioid granulomas that may affect any organ system.
Clinical features:
Patients most commonly present in winter and early spring, which suggests a possible environmental trigger. The onset is usually insidious, and findings may be discovered on routine chest radiographs.
- General manifestations: One third of patients have constitutional symptoms, such as fever, fatigue, and weight loss.
- Pulmonary system: The lungs are affected in most patients. Symptoms occur in one third to one half of patients and most commonly include dyspnea, dry cough, and chest tightness or pain. The disease can progress to parenchymal infiltration and, ultimately, irreversible fibrosis.
- Lymphatic system: One third of patients with sarcoidosis have palpable lymph nodes that are moveable and nontender. Right paratracheal lymph node enlargement is most commonly seen, followed next by cervical nodes.
Imaging features:
In sarcoidosis, clinical staging is based on the chest radiograph:
- Stage 0: Normal chest radiograph
- Stage I: Hilar and mediastinal lymph node enlargement
- Stage II: Lymphadenopathy and parenchymal disease
- Stage III: Parenchymal disease only
- Stage IV: Pulmonary fibrosis
Intrathoracic lymphadenopathy is the most common finding in sarcoidosis occurring in over 85% of patients. The most common pattern is right paratracheal and bilateral hilar adenopathy (the \"1,2,3 sign\"). Unusual patterns of lymph node enlargement occasionally occur. While not common, paratracheal, subcarinal, aortopulmonary window, and other mediastinal lymph node groups can be involved in the absence of hilar disease.
The radiographic appearance of parenchymal disease can be fine nodular, reticulonodular, acinar and very rarely focal (solitary nodule or mass). Acinar opacities in sarcoidosis may coalesce to give the appearance of the so-called alveolar form of sarcoidosis.
Posteroanterior (PA) and lateral radiographs show prominence of both hila , widening of the right paratracheal stripe and obliteration of the aortopulmonary window . Multiple small nodules are visible in both lungs. The lung volumes are decreased.
Computed tomography (CT) is more sensitive than chest radiography in the detection of adenopathy and subtle parenchymal disease. High resolution CT (HRCT), by demonstrating fine anatomic detail, can show the distribution of the granulomas. HRCT findings include areas of ground-glass appearance, subpleural and perivascular nodules, irregular thickening of bronchovascular bundles, and thickening of interlobular septa. Although nodular thickening of interlobular septa (so-called \"beaded septa sign\") is more commonly described in lymphangitic spread of tumor, it can also be seen in sarcoidosis.
Computed tomography (CT) is more sensitive than chest radiography in the detection of adenopathy and subtle parenchymal disease. High resolution CT (HRCT), by demonstrating fine anatomic detail, can show the distribution of the granulomas. HRCT findings include areas of ground-glass appearance, subpleural and perivascular nodules, irregular thickening of bronchovascular bundles, and thickening of interlobular septa. Although nodular thickening of interlobular septa (so-called \"beaded septa sign\") is more commonly described in lymphangitic spread of tumor, it can also be seen in sarcoidosis.
HRCT findings seen in our patient :
Extensive peribrochovascular nodularity is seen associted with consolidation and air bronchogram secondary to coalscence of the peribronchovascular nodularity.Subpleural, fissural and septal nodularity is also observed.
Tractional bronchietcatic changes are seen due to extensive fibrotic changes.The disease is predominantly in the upper lobe.
Multiple lymph nodes are seen in the paratracheal,subcarinal and pretracheal region.
Tractional bronchietcatic changes are seen due to extensive fibrotic changes.The disease is predominantly in the upper lobe.
Multiple lymph nodes are seen in the paratracheal,subcarinal and pretracheal region.