title: Localized pleuropulmonary crystal-storing histiocytosis: 5 cases of a rare histiocytic disorder with variable clinicoradiologic features.
abstract: Crystal-storing histiocytosis (CSH) localized to the thoracic region is a rare occurrence, often secondary to lymphoproliferative or plasma cell diseases. About 10 case reports have been previously published, and 3 of these have no relationship with clonal hematologic disorders. We collected here the first series of 5 consecutive cases of CSH involving lungs (4 cases) and pleura (1 case). There were 3 women and 2 men with a mean age at diagnosis of 65 years. All cases had an underlying hematologic disorder (2 B-cell marginal-zone lymphomas, 2 monoclonal gammopathy of undetermined significance and 1 pulmonary plasmacytoma). Despite a common morphology characterized by a dense and irregular growth of large eosinophilic histiocytes with intracytoplasmic refractile crystals, 2 cases presented with cystic changes at gross and imaging examinations, calcified amyloid was found in 2 cases, and 1 case showed an interstitial lung disease with nonspecific interstitial pneumonia pattern. Histiocytes were immunoreactive for CD68 (clones PGM-1 and KP-1) but were not for CD1a and S100; the associated lymphoplasmacellular disorder had a clonal profile on molecular analysis with κ light-chain restriction. Two cases were originally misdiagnosed as cystic fibrohistiocytic tumor and carcinoid tumor, thus confirming that CSH localized to this site may result in a diagnostic challenge with a broad spectrum of differential diagnoses. The presence of intracytoplasmic crystals and a plasma cell infiltrate around a histiocytic proliferation should alert the pathologist to consider CSH and to carefully investigate the presence of clonal hematologic disease.
authors: Unità di Anatomia Patologica, Azienda Ospedaliera Arcispedale Santa Maria Nuova/Istituto di Ricerca e Cura a Carattere Scientifico, Reggio Emilia, Italy. giurossi68@gmail.com
authors: Giulio
authors: G
authors: Rossi
authors: Nicoletta
authors: N
authors: De Rosa
authors: Alberto
authors: A
authors: Cavazza
authors: Maria Cecilia
authors: MC
authors: Mengoli
authors: Giovanni
authors: G
authors: Della Casa
authors: Nazarena
authors: N
authors: Nannini
authors: Thomas Vail
authors: TV
authors: Colby
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D015614:Histiocytosis / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008171:Lung Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D018442:Lymphoma, B-Cell, Marginal Zone / Q000150:complications; D008297:Male; D008875:Middle Aged; D010265:Paraproteinemias / Q000150:complications; D010954:Plasmacytoma / Q000150:complications; D010995:Pleural Diseases / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D011859:Radiography