Review of diagnostic methods and results for HIV-associated disseminated histoplasmosis: Pathologists are not sufficiently involved.

Objectives: Disseminated histoplasmosis is a major killer of HIV-infected persons in Latin America. Antigen detection, fungal culture and Polymerase Chain Reaction are often not available, but cytology and histology are present in most hospitals and may offer a diagnostic alternative. In this study, we review 34 years of clinical experience to describe the roles of cytology and histology in diagnosing disseminated histoplasmosis.

Methods: Retrospective multicentric study of 349 patients between 1 January 1981 and 1 October 2014 with confirmed disseminated histoplasmosis.

Results: Around 32/214 (14.9%) of samples were screened using cytopathology, as were 10/101 (9.9%) bronchoalveolar lavage samples and 5/61 (8.2%) of spinal fluid samples. The samples most commonly sent to pathology were liver biopsies, lower digestive tract and lymphnode biopsies; the greatest proportion of positive results were found in lower digestive tract (43/59 (72.9%) positives), lymph node (39/63 (66.1%)), and liver (38/75 (50.7%)) samples. Overall, 97.2% of bone marrow and 97% of bronchoalveolar lavage samples were directly examined by a mycologist. Positive direct examination was independently associated with death (aHR = 1.5 (95%CI = 1-2.2)).

Conclusions: Opportunities for a rapid diagnosis were regularly missed, notably for bone marrow samples, which could have been examined using staining methods complementary to those of the mycologist.