Skip to Main Content

++

Essentials of Diagnosis

++

  • • Nonproductive cough and dyspnea with or without systemic symptoms.
  • • Extrathoracic involvement (5–15%) of bones, skin, hypothalamus, liver, spleen, and lymph nodes.
  • • Nodular or cystic pattern on high-resolution computed tomography with basal sparing.
  • • Demonstration of Langerhans’ cells and bronchiolocentric granuloma on lung biopsy or increased (>5%) CD1a-positive cells on bronchoalveolar lavage.

++

General Considerations

++

Pulmonary Langerhans’-cell histiocytosis (PLH) is part of a spectrum of diseases characterized by proliferation of and infiltration by Langerhans’ cells into various organs. Several organ systems may be involved in Langerhans’-cell histiocytosis (LCH), including the lungs, bone, skin, pituitary gland, liver, lymph nodes, and thyroid (Figure 14–1). Lung involvement may occur either in isolation or as part of a multisystem syndrome. When lung disease is part of the clinical presentation in adult patients, the term pulmonary Langerhans’-cell histiocytosis is used.

++
Figure 14–1.
Graphic Jump Location

Organ involvement in Langerhans’-cell hystiocytosis in adults.

++

The nomenclature of these syndromes is diverse. Older classification schemes used designations such as systemic histiocytosis X, eosinophilic granuloma, Letterer–Siwe disease, Hand–Schuller–Christian syndrome, Hashimoto–Pritzker syndrome, and Langerhans cell granulomatosis. To avoid confusion due to eponymous conflicts, the Histiocyte Society established a simplified classification scheme based on a spectrum of presentations that varies from those involving single organs to more aggressive, disseminated disease. These diseases should be referred to as Langerhans’-cell histiocytosis and the presence of specific organ involvement should be described. In patients with pulmonary manifestations, the lung is the only organ system affected in approximately 85%, whereas multisystem disease is seen in 5–15%.

++

The exact prevalence and incidence of PLH are unknown. However, it appears that this is a rare disease. In one study of those undergoing open-lung biopsy for interstitial lung disease, only 15 cases of PLH were detected among 501 patients over 6 years, whereas 274 cases of sarcoidosis were found. Another study of biopsy specimens from patients with interstitial lung disease found PLH in 5%. However, it has been suggested that PLH may be underdiagnosed as some patients have a paucity of symptoms or undergo a spontaneous remission and never undergo a confirmatory biopsy.

++

There does not seem to be a familial basis to PLH. The specific genetic factors involved are not known. It appears to be a disease largely of white individuals with no specific geographic predilection. Likely, there is no gender predominance. Early series suggested a male bias, but more recent series have called this into question. Changing patterns in tobacco consumption, with more women now smoking, may have caused this apparent shift. Most patients are between 20 and 40 years of age, but pulmonary involvement has been described in individuals from 3 months to 69 years of age.

++

The one identifiable and consistent risk factor for PLH is cigarette smoking. In ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.