Cytological and Histopathological Spectrum of Histoplasmosis: 15 Years of Experience in French Guiana

Abstract

nodes were positive in 42 specimens (31 histology and 11 cytology). Histopathological analysis of the 31 lymph nodes showed a variable histological appearance. Tuberculoid forms were most frequent (24/31, 77,4%).Conclusions: From the pathologist perspective, this is the largest series to date showing that digestive involvement was the most frequent, usually with a tuberculoid form and a greater load of Histoplasma. With awareness and expertise, cytology and pathology are widely available methods that can give life-saving results in a short time to help orient clinicians facing a potentially fatal infection requiring prompt treatment.

Reduced Severity in Patients With HIV-Associated Disseminated Histoplasmosis With Deep Lymphadenopathies: A Trench War Remains Within the Lymph Nodes?

“…In our Histoplasmosis pathology experience, 31 patients had histological confirmation of lymph node histoplasmosis by the presence of H. capsulatum yeasts on lymph node biopsies or surgical specimens. Interestingly and consistently with the clinical outcome of this study the granulomatous inflammatory reaction of tuberculoid type was the most frequent (24/31, 77.4%) which usually corresponds to effective tissue response ( Drak Alsibai et al., 2020 ). Among these 24 granulomatous cases, histological variants perfectly mimicking tuberculosis with epithelioid granulomas, multinucleated giant cells and caseous necrosis were found in 10 cases, followed by less typical epithelioid granulomatous variants where giant cells and necrosis were absent in eight cases, then by forms with predominant macrophage infiltration in six cases.…”

Cytological Spectrum of Pulmonary Histoplasmosis Diagnosed by Bronchoalveolar Lavage: 12 Years of Experience in French Guiana

“…In HIVinfected patients, all BALs were macrophage-dominant. In a recent experiment concerning the histological appearance of histoplasmosis, we demonstrated that the macrophagepredominant microenvironment is the most frequent in HIV patients [12]. This microenvironment is represented by two histological forms: the granulomatous (or tuberculoid) form and the intermediate form.…”

“…These two forms are rich in macrophages or epithelioid cells derived from macrophages. In addition, in the anergic form and the sequelae form, the host inflammatory responses to H. capsulatum are very weak [12]. Nevertheless, it should be remembered that BAL is a medium naturally rich in alveolar macrophages.…”

“…The reference methods for detecting H. capsulatum in immunocompromised patients are fungal cultures performed by laboratories and cytological and/or histological examination performed in pathology departments with a sensitivity of 80% and 65%, respectively [10][11][12]. Nevertheless, given the complexity of a pathologist's specialty, the sensitivity of cytological and histological examination in the diagnosis of histoplasmosis depends on the pathologist's experience in the detection of pathogens [12].…”

“…In addition, the performance of diagnostic methods depends on the type and quality of specimen, the clinical pattern and tissue sampling, and the immune status of the patient [13,15]. Cytological and histological examination is usually present in most hospitals and can represent an important diagnostic alternative [12]. H. capsulatum appears as small spherical or ovoid yeasts <6 µm in size.…”