Langerhans Cell Histiocytosis: A Single Institution Retrospective Analysis of Eleven Patients

Langerhans cell histiocytosis (LCH), is a rare disorder which has a substantially unknown etiology, pathophysiology, and may manifest through a variety of clinical presentations ranging from solitary eosinophilic granuloma to severe multisystem disease. LCH is more common in children, although it can affect any age; the most common sites of involvement are bone, skin, and lung.

From a histological point of view LCH derives from accumulation of proliferating cells with surface markers and ultrastructural features similar to cutaneous Langerhans cells, intermixed with inflammatory cells, particularly eosinophils.

Below, a retrospective analysis of LCH patients treated at our institution.

Between 1997 and 2013 we have treated 11 LCH patients, including 6 females and 5 males with a median age at time of diagnosis of 42.9 years (range 22.2-62.3). All diagnoses were reviewed by our pathologist.

With regard to the site at onset, 9 patients had bone involvment, among these, four patients had only bone involvment, the other five patients also lung, oral cavity and lymph nodes.

At time of onset 4 patients showed no symptoms, while the remaining 7 showed a variety of symptoms ranging from B symptoms to tinnitus, dizziness, and other neurological symptoms such as diplopia. Among the study group 6 patients had multisystemic involvement.

All patients except one had CT scan performed before, during, and at follow-up, the remaining patient was studied and followed through follow-up with PET scan.

As first-line therapy 8 patients underwent chemotherapy, 2 patients radiation therapy, 1 patient required only steroid therapy. The most frequently used chemotherapy regimen for these 8 patients was MACOP-B, a third generation, CHOP-like regimen.

Responses to first-line therapy were as follows: 7 complete remissions (CR), resulting with chemotherapy (5), radiation therapy and steroid therapy, two partial remissions (both obtained with chemotherapy) and two stable diseases (1 with chemotherapy and 1 with radiation therapy).

Two patients relapsed, of whom one has ran several lines of chemotherapy, including autologous stem cell transplantation. Both are alive at the time of the last follow-up.

To date all patients are alive but one, who died of pulmonary embolism while he was in stable disease. Six patients are in CR (60%), two in SD (20%) and two in PD (20%).

In conclusion, our monocentric experience of 11 LCH patients confirms what reported in the literature in terms of heterogeneity of presentation, age, sites of involvement, symptomatology and treatment demanded. Coming to the the results our retrospective analisys shows that ten of the eleven study population patients (90.9%) are to date still alive after a significant median time of follow-up; six out of these ten patients (60%) are in CR.