lymphocytic interstitial pneumonitis

Lymphocytic interstitial pneumonitis is a benign lymphoproliferative disorder characterized by lymphocyte predominant infiltration of the lungs. It is classified as a subtype of interstitial lung disease. It also falls under the umbrella of non-lymphomatous pulmonary lymphoid disorders.

Epidemiology

Lymphocytic interstitial pneumonitis can occur at any age. However, most of the patients are adults with a mean age of 50 years. If a child presents with lymphocytic interstitial pneumonitis, this can be indicative of AIDS.

There is a recognized female predilection most likely attributable to the fact that lymphocytic interstitial pneumonitis occurs in patients with autoimmune disease such as Sjögren syndrome, which is by far more common in women .

Clinical presentation

The main clinical symptoms are a gradual onset of dyspnea and cough with approximately six months duration. Less frequently, patients may have systemic symptoms such as fever, night sweat, arthralgia, and weight loss. If the disease progresses to the end-stage respiratory failure cyanosis and clubbing may develop. Hypertrophy of the salivary glands observed in 20% of patients .

Pathology 

There is diffuse infiltration of the interstitium and alveolar spaces by lymphocytes and plasma cells.

Associations
Markers

In about 80% of patients polyclonal or IgM monoclonal gammopathy is found .

Radiographic features

Plain radiograph

Features can be non-specific, but may include:

CT

The following features may be seen with lymphocytic interstitial pneumonitis on HRCT, but the findings are not exclusive to its diagnosis:

Treatment and prognosis 

The natural history is variable, from near-complete resolution to progressive disease. More than 30% of patients will develop the end-stage disease and honeycombing despite treatment.

Transformation to lymphoma can occur, particularly in a patient with monoclonal gammopathy or hypogammaglobulinemia . Corticosteroids have been successfully trialled .

Differential diagnosis

General imaging differential considerations include:

See also