As part of the activity of the Basic Prevention Unit of the Osakidetza Alav University Hospital, medical consultations are carried out at the request of the workers.
The worker, a 41-year-old administrative assistant, first came to our Unit on 4 December 2013.
The symptoms she presented with were a cough, especially at night, sneezing, a feeling of fatigue, with no fever or accompanying expectoration. She also reported a frontal headache with tension features. The cough and feeling of fatigue had been present for several weeks.
Personal history: allergy to mites, grasses and animal epithelium. She smoked 20 cigarettes/day, with a high level of dependence (according to the Fagerstrom test).
She did not take any medication, nor did she have any other additional pathology, except that a few years ago she had presented papular, pinkish lesions on her fingers, which were assessed by Dermatology as Granuloma annulare and treated with topical corticoids.
It should be noted that she had a pet cat, which she could not do without.
On examination, cardiopulmonary auscultation was normal, with no signs of neurological involvement.
Initially, it was thought to be an allergic condition, probably related to the cat's epithelium. Treatment was prescribed with inhaled bronchodilators and analgesics for her headache, and she was scheduled for a follow-up appointment in 10 days.
The worker improved substantially with the bronchodilator and did not attend a check-up. When she stopped the bronchodilators on her own initiative, she again presented with coughing and a more pronounced sensation of dyspnoea. She returned to our clinic one month after the initial visit, with similar coughing symptoms and a feeling of fatigue, with a normal cardiopulmonary examination, so spirometry and chest X-ray were requested.
The spirometry performed on the worker was strictly normal.
The chest X-ray requested showed images of millimetric nodules predominantly in both upper fields, which were not present in the patient's chest X-ray of February 2012. A high-resolution CAT scan (HRCT) was requested, and at the same time a consultation was made with Pneumology, completing the study with CO2 diffusion tests and pulmonary flow curve.

The CAT scan showed bilateral pulmonary involvement, predominantly in the upper fields, with thickening of the bronchial walls. Scattered nodules, some cavitated inside, giving rise to cystic images.

The CO2 diffusion tests and pulmonary flow curve were within normal parameters.
Complete blood tests were carried out and ANCA and ANA were negative.
Given the radiological findings described in the CT scan and the smoking habit, the initial diagnostic suspicion was of Histiocytosis X, so it was decided to refer for confirmation by lung biopsy, for which a bronchoscopy was performed and samples were taken using the cryobiopsy technique.
The cryobiopsy probe is located 1-2 cm from the pleura using fluoroscopy.

The cryoprobe used is a flexible probe with a diameter of 2.4mm, which is connected to the cryotherapy equipment. The freezing of the tissue to which the probe is applied results from the decompression of the gas (nitrous oxide) at the end of the probe, which allows the extraction of a traction-stable sample. As with transbronchial biopsies, the probe is introduced through the bronchoscope and cold is applied for 3 seconds. The difference to the traditional clamp technique is that in this case sedation of the patient is required, which on the other hand provides greater comfort and better tolerance.
Emphysema changes and intra-alveolar accumulations of histiocytes with fine brownish cytoplasmic pigmentation associated with hyperplastic pneumocytes are described.

Immunohistochemistry showed nodular clusters of CD1-positive cells, compatible with Langerhans cell histiocytosis.