title: Granulomatous Reaction to Pneumocystis jirovecii Diagnosed in a Bronchoalveolar Lavage: A Case Report.
abstract: BACKGROUND
  Granulomatous reaction to Pneumocystis jirovecii is a rare but well-known pathological finding encountered in the setting of immunosuppression, HIV infection being the most common cause. It can also potentially complicate the treatment of hematological malignancies, typically when drugs lowering the count and function of lymphocytes are used. Lung biopsy is considered the gold standard for the diagnosis of granulomatous P. jirovecii pneumonia, whereas the diffuse alveolar form is usually detected cytologically in bronchoalveolar lavage (BAL).
  
  
  METHODS
  A female patient pursuing R-CHOP chemotherapy for the treatment of multiple hematological malignancies developed a rapidly progressing dyspnea. Chest CT scans revealed a worsening of a known infiltrative lung disease thought to be secondary to her chemotherapy. Alterations compatible with a drug-induced interstitial lung disease and well-formed focally necrotizing granulomas were observed on an open lung biopsy, but no microorganism was identified with special stains. Eventually, a granulomatous reaction to P. jirovecii was found in a BAL and allowed appropriate treatment with rapid improvement of the dyspnea.
  
  
  CONCLUSIONS
  Because granulomas are tissue-bound structures, they are rarely described in BAL. This article describes the first reported cytological diagnosis of a granulomatous reaction to P. jirovecii and the potential diagnostic interest of such a peculiar finding.
authors.affiliation: Institute of Pathology, Centre Hospitalier Universitaire Vaudois and University of Lausanne, Lausanne, Switzerland.
authors.forename: Antoine
authors.initials: A
authors.lastname: Nobile
authors.forename: Antonio
authors.initials: A
authors.lastname: Valenti
authors.forename: John-David
authors.initials: JD
authors.lastname: Aubert
authors.forename: Catherine
authors.initials: C
authors.lastname: Beigelman
authors.forename: Igor
authors.initials: I
authors.lastname: Letovanec
authors.forename: Massimo
authors.initials: M
authors.lastname: Bongiovanni
mesh_terms: D000368:Aged; D058846:Antibodies, Monoclonal, Murine-Derived / Q000009:adverse effects; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000009:adverse effects*; D001992:Bronchoalveolar Lavage Fluid / Q000382:microbiology*; D003520:Cyclophosphamide / Q000009:adverse effects; D004317:Doxorubicin / Q000009:adverse effects; D005260:Female; D015769:Granuloma, Respiratory Tract / Q000209:etiology / Q000473:pathology*; D019337:Hematologic Neoplasms / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D006801:Humans; D016867:Immunocompromised Host; D045363:Pneumocystis carinii / Q000302:isolation & purification*; D011020:Pneumonia, Pneumocystis / Q000382:microbiology / Q000473:pathology*; D011241:Prednisone / Q000009:adverse effects; D011379:Prognosis; D000069283:Rituximab; D014750:Vincristine / Q000009:adverse effects
chemical_list: D058846:Antibodies, Monoclonal, Murine-Derived; C571759:R-CHOP protocol; D000069283:Rituximab; D014750:Vincristine; D004317:Doxorubicin; D003520:Cyclophosphamide; D011241:Prednisone