Pulmonary histiocytosis X

An unusual radiological presentation of pulmonary Langerhans' cell histiocytosis

Langerhans' cell histiocytosis is a proliferative disease of the dendritic cell lineage. It usually has a characteristic radiological presentation of apical nodules and small cysts occurring predominantly in young adult smokers. Here we report a case of multisystem Langerhans cell histiocytosis in a 75-year-old woman with unusual chest radiology.

Langerhans cell histiocytosis with thyroid and lung involvement in a child: a case report

Langerhans cell histiocytosis (LCH), a monoclonal disease of histiocytes, may involve several organ systems but rarely primarily involves the thyroid gland. This report presents an extremely rare case of LCH of the thyroid and lungs in a 3-year-old boy who presented with a neck mass for several weeks. The patient subsequently underwent chemotherapy with resolution of the goiter and lung findings, and the patient remained in complete remission 1 year after chemotherapy. LCH of the thyroid should be considered in the differential diagnosis of a child with a thyroid mass. Pulmonary examination should be done in these patients.

Smoking-related interstitial lung diseases: radiologic-pathologic correlation

Smoking-related interstitial lung diseases (SRILD) are a heterogeneous group of entities of unknown cause. These diseases include desquamative interstitial pneumonia (DIP), respiratory-bronchiolitis-related interstitial lung disease (RB-ILD), pulmonary Langerhans' cell histiocytosis (LCH) and idiopathic pulmonary fibrosis (IPF). High-resolution CT is highly sensitive in the detection of abnormalities in the lung parenchyma and airways. Ground-glass attenuation can occur in DIP and RB-ILD. Whereas DIP is histologically characterized by intra-alveolar pigmented macrophages, RB-ILD shows alveolar macrophages in a patchy peribronchiolar distribution. LCH shows nodular infiltrates on histopathological examination containing varying amounts of characteristic Langerhans' histiocytes. The HRCT findings are characteristically bilateral, symmetrical and diffuse, involving the upper lobe zones with sparing of the costophrenic angles. The most prominent CT features are nodules (sometimes cavitary) measuring 1 to 10 mm in diameter, cysts and areas of ground-glass attenuation. Pathologically, IPF is characterized by its heterogeneity with areas of normal lung, alveolitis and end-stage fibrosis shown in the same biopsy specimen. High-resolution CT findings consist of honeycombing, traction bronchiectasis and intralobular interstitial thickening with subpleural and lower lung predominance. Since coexisting lesions in the same cases have been observed, a better understanding of the different smoking-related interstitial lung diseases (SRILD) allows a more confident and specific diagnosis.

From the Archives of the AFIP

Pulmonary Langerhans cell histiocytosis (PLCH) is an isolated form of Langerhans cell histiocytosis that primarily affects cigarette smokers. PLCH is characterized by peribronchiolar proliferation of Langerhans cell infiltrates that form stellate nodules. The nodular lesions frequently cavitate and form thick- and thin-walled cysts, which are thought to represent enlarged airway lumina. PLCH lesions display temporal microscopic heterogeneity, with progression from dense cellular nodules to apparently cavitary nodules to increasing degrees of fibrosis that may extend along alveolar walls. In advanced cases, fibrotic scars are surrounded by enlarged, distorted air spaces. Affected patients are typically young adults who often present with cough and dyspnea. The characteristic radiographic features of PLCH are bilateral nodular and reticulonodular areas of opacity that predominantly involve the upper and middle lung zones with relative sparing of the lung bases. High-resolution computed tomography (CT) shows nodules and cysts in the same distribution and allows a confident prospective diagnosis of PLCH in the appropriate clinical setting. In typical cases, a predominantly nodular pattern is seen on CT scans in early phases of the disease, whereas a cystic pattern predominates in later phases. The radiologic abnormalities may regress, resolve completely, become stable, or progress to advanced cystic changes. Treatment consists of smoking cessation, but corticosteroid therapy may be useful in selected patients. Chemotherapeutic agents and lung transplantation may be offered to patients with advanced disease. The prognosis of PLCH is variable with frequent regression, stabilization, or recurrence of disease that does not correlate with cessation or continuation of smoking.

Pulmonary Langerhans cell histiocytosis: emerging concepts in pathobiology, radiology, and clinical evolution of disease

Pulmonary Langerhans cell histiocytosis (PLCH) is an uncommon disorder of adult smokers associated with a significant morbidity. Arising from the aberrant accumulation of Langerhans and other immune cells, PLCH tends to cause a relatively isolated pulmonary involvement as compared to other forms of Langerhans cell (LC) and histiocytic disorders. Increased knowledge of cytokine triggers, dendritic cell trafficking, and clonality of LC populations in PLCH have resulted in an improved understanding of the pathobiology of PLCH. High-resolution CT (HRCT) of the chest has led to better appreciation of nodular and cystic radiographic abnormalities characteristic of the disease. Correlation of HRCT abnormalities with lung pathologic changes has led to an improved comprehension of clinical evolution of PLCH. Current clinical predictors for PLCH outcomes remain poor, although long-term follow-up and radiologic monitoring may help to define disease progression. This review discusses advances in PLCH emphasizing the etiopathologic bases of the disease and currently available radiologic modalities for monitoring disease progression.

Pulmonary abnormalities at long-term follow-up of patients with Langerhans cell histiocytosis

BACKGROUND

In Langerhans cell histiocytosis (LCH) pulmonary involvement, which is often initially asymptomatic, may contribute to significant morbidity and mortality. To determine the long-term prognosis, a cross-sectional study was undertaken.

PROCEDURE

Forty-one patients with > or = 5 years follow-up after the diagnosis of LCH were interviewed and underwent physical examination, blood tests, a chest X-ray and a high-resolution CT (HRCT) of the lungs. All patients included had been referred to the Department of Pediatrics at the Karolinska Hospital in Stockholm between July 1962 and February 1990 (median follow-up 16 years). Biopsies from all patients were reviewed and confirmed to be consistent with LCH. Information on previous clinical features including treatment and the results of chest X-rays were also collected for risk factor analysis.

RESULTS

Radiographic abnormalities of the lungs (cysts and/or emphysema), found in 10/41 (24%) at follow-up, were classified into five groups according to the extent of the cysts. These patients had more often suffered from multisystem than from single-system disease (P = 0.01), were significantly older at diagnosis (P < 0.001), and had been more heavily treated with chemotherapy and/or radiotherapy. They were also more frequently smokers (P < 0.0001) and 7/10 (70%) had suffered lung involvement at diagnosis. At the time of diagnosis of the pulmonary involvement, 4/10 (40%) patients had respiratory symptoms, but only 2/10 (20%) had symptoms at follow-up.

CONCLUSIONS

Ten (24%) of the 41 patients had abnormal findings on radiological examination of the lungs at long-term follow-up and seven are or had been smokers. It is of great importance that patients with LCH be informed about smoking-related pulmonary morbidity. Prolonged monitoring of the lungs for smokers and patients with known pulmonary involvement is recommended.

Controversies and new approaches to treatment of Langerhans cell histiocytosis

There continues to be genuine ambivalence as to whether Langerhans cell histiocytosis (LCH) is a primary neoplastic or immuno-dysregulatory disorder. Treatment strategies have moved from one camp to the other depending upon the most current alleged successes or failures. This has been particularly true for patients who fall outside of the sphere where treatment is minimal or where known treatment approaches are clearly beneficial. However, there is growing evidence that LCH is both the result of clonal proliferation of Langerhans cells and the immunologic consequence of increased cellular activation. This new knowledge should be the basis for the development of new therapeutic approaches for patients with LCH and its complications.

Expiratory high-resolution CT scan

Although high-resolution CT scan has proved most useful in the diagnosis of infiltrative lung disease, its use in the diagnosis of airway and obstructive lung diseases has recently been emphasized. In particular, the use of dynamic expiratory or postexpiratory CT scans, usually in combination with an inspiratory high-resolution CT scan study, has proved useful in the diagnosis and assessment of obstructive lung diseases. This article reviews the use of expiratory CT scan in the diagnosis of lung disease, including the various CT scan techniques that can be used, normal and abnormal expiratory CT scan findings, and the use of expiratory CT scan in a variety of obstructive diseases.

Diagnostic and management strategies for diffuse interstitial lung disease

Patients with diffuse interstitial lung diseases (DILD) are challenging to treat. Many patients with DILD have inadequate information about the disease process, an imprecise diagnosis, unsatisfactory treatment or unacceptable side effects associated with therapy, and poorly controlled symptoms of progressive illness. Establishing an accurate diagnosis is necessary so that the patient and his/her family can be provided with reasonable expectations about prognosis and outcome from therapy. A pragmatic approach is presented that emphasizes diagnostic strategies and plans for therapy that are effective and resource efficient and that will help maintain patient satisfaction.

Epidemiologic study of Langerhans cell histiocytosis in children

OBJECTIVE

The etiology and pathogenesis of Langerhans cell histiocytosis (LCH) remain poorly understood. We conducted an exploratory epidemiologic study to investigate potential risk factors associated with LCH.

STUDY DESIGN

We used a case-control study design to obtain data from parents of children with LCH (n = 459) who were members of the Histiocytosis Association of America and Canada. The two control groups consisted of 683 community control subjects and 3719 children with childhood cancers treated at participating Children's Cancer Group institutions.

RESULTS

The median age at diagnosis of LCH was 1.8 years (range 0.1 to 14.6 years). Cases were categorized as multisystem LCH (MS-LCH) (n = 208) and single-system LCH (SS-LCH) (n = 198). Statistically significant associations included the following: infections in the neonatal period (MS-LCH, odds ratio (OR) = 2.2), solvent exposure (SS-LCH, OR = 54.9), childhood vaccinations (MS-LCH and SS-LCH, OR = 0.4), thyroid disease in the proband (MS-LCH and SS-LCH, OR = 21.6), and family history of thyroid disease (MS-LCH and SS-LCH, OR = 1.4). The association with thyroid disease in the proband was explained partially by the involvement of the pituitary, with the relative risk decreasing when patients with diabetes insipidus and thyroid involvement were excluded from analysis.

CONCLUSIONS

This large hypothesis-generating study provides directions for future investigations in well-designed population-based or hospital-based epidemiologic studies.

Langerhans cell histiocytosis: an exploratory epidemiologic study of 177 cases

There is little information available regarding epidemiologic risk factors for Langerhans cell histiocytosis (LCH). An exploratory investigation was conducted using information obtained from parents of 177 cases of LCH diagnosed before 21 years of age (median 2 years). Utilizing data available from the Children's Cancer Group, LCH cases were compared to two matched control groups including 614 patients diagnosed with a variety of childhood cancers and 318 community controls. Questionnaire data included information on demographics, prenatal and perinatal factors, complications in the neonatal period, environmental exposures, family medical history, and childhood exposures. Factors found to be statistically significantly associated with an increased risk of LCH included: maternal urinary tract infection during the index pregnancy, feeding problems during infancy, and blood transfusions during infancy. Use of supplemental vitamins was associated with a significantly decreased risk of LCH. Results from this exploratory study provide a basis for speculation on potential etiologic risk factors for LCH. Future epidemiologic investigations of LCH need to consider the presenting disease characteristics in assessing possible etiologic factors.

Bronchogenic carcinoma in patients with pulmonary histiocytosis X

Five cases of bronchogenic carcinoma were observed among 93 patients with pulmonary histiocytosis X (Hx). Mean age at the time of diagnosis of Hx was 42 years; on the average, cancer occurred 10.5 years later. All patients were smokers and continued to smoke heavily at the time of diagnosis of cancer. Comparison of the five cases associating Hx and lung carcinoma with a group of 88 control patients suffering from Hx alone suggested that smoking played the predominant role in the pathogenesis of cancer. In fact, among the four patients with Hx and carcinoma older than 45 years, tobacco consumption was significantly greater (64.7 +/- 37 pack-year, mean +/- SD) than that of the 15 control patients of the same age with only Hx (40.8 +/- 11.6, p less than 0.01). In light of this good correlation, the diagnosis of Hx strongly advocates stopping tobacco smoking and long-term medical follow-up.

Value of CD-1-positive cells in bronchoalveolar lavage fluid for the diagnosis of pulmonary histiocytosis X

Pulmonary histiocytosis X is characterized by an accumulation of CD-1-positive histiocytosis X cells in the lung, which also can be found in the bronchoalveolar lavage fluid (BALF). However, it has recently been demonstrated that CD-1-positive cells can also be detected in BALF of patients with other interstitial lung diseases and in healthy smokers. We therefore examined the frequency of CD-1-positive cells in a pool of patients with different pulmonary disorders, according to their smoking habits and diagnoses. We have studied the bronchoalveolar lavage in patients with pulmonary histiocytosis X (n = 6), sarcoidosis (n = 88), and in 97 patients with other miscellaneous lung disorders by using the immunoperoxidase method to detect CD-1-positive cells on glass slides. All patients with histologically proven histiocytosis X displayed more than 5% CD-1-positive cells, whereas patients with other pulmonary disorders showed no more than 3.6% CD-1-positive BAL cells. The dividing line of 5% CD-1-positive cells was not influenced by patients' smoking habits. The identification of CD-1-positive cells in BALF appears to be useful in diagnosing pulmonary histiocytosis X.

Eosinophilic granuloma of the lung presenting as a solitary pulmonary nodule

A symptomless 58 year old man had an eosinophilic granuloma of the lung that presented as a solitary pulmonary nodule rather than the usual diffuse reticulonodular shadow on the chest radiograph. Only one previous case presenting in this way has been described.

Pulmonary histiocytosis X with mediastinal lymph node involvement

In this report, we describe a patient with the classic histology of pulmonary histiocytosis X, who had bilateral reticulonodular densities and mediastinal lymph node involvement. The diagnosis was confirmed by the use of electron microscopy and immunohistochemical markers (PS100, HLA-DR, and CD1), which allowed us to recognize the lymph node infiltration of X histiocytes. An association of mediastinal lymph node enlargement with pulmonary histiocytosis X has been reported but it has never been histologically documented.

Endobronchial eosinophilic granuloma: a rare cause of total lung atelectasis

A 12-yr-old male presented with left lung atelectasis secondary to a mainstem endobronchial mass. At thoracotomy, a left mainstem bronchial sleeve resection successfully extirpated what later proved to be an eosinophilic granuloma. This is the first case report, to our knowledge, of endobronchial eosinophilic granuloma.