Intestinal Paracoccidioidomycosis Masquerading as Crohn's Disease: Diagnostic Pitfalls in a Case Report.
Cerqueira Ana A, Seco Tiago T, Moniz Joana J, Lemos Bárbara B et al.
Paracoccidioidomycosis (PCM) is a systemic fungal infection caused by Paracoccidioides spp., predominantly found in Brazil. It primarily affects the respiratory system, while extrapulmonary involvement is rare. Disseminated PCM in immunocompetent hosts may be associated with exposure burden, host factors, delayed diagnosis, and disease phenotype. We present the case of a 28-year-old Brazilian man who had been living in Portugal for five months and presented to the emergency department with persistent abdominal pain lasting three weeks. Initial evaluation revealed mesenteric lymph-node conglomerates. During hospitalization, an extensive workup was performed, including screening for active neoplastic disease, immunosuppressive states, and active infection. A fourth-generation HIV combined antigen/antibody test was negative. Immunoglobulin levels were within the normal range (immunoglobulin A 160 mg/dL, immunoglobulin M 200 mg/dL and immunoglobulin G 1500 mg/dL). There was no history of immunosuppressive medication use including steroid or biologic, and no history of diabetes or transplantation. There was also no clinical or imaging evidence of solid or haematological malignancy. Immunophenotyping of peripheral blood and two lymph nodes showed no changes of pathological significance. Clinical, imaging, endoscopic, and histologic findings suggested Crohn's disease, although the presentation was atypical because of the extent of painful lymphadenopathy and hepatosplenomegaly. However, Periodic Acid-Schiff (PAS) and Ziehl-Neelsen staining were performed on the initial slides containing granulomas (inguinal lymph node and samples from the ileum and colon, but did not demonstrate evidence of infection at that time). A trial with high-dose corticosteroids was initiated. Following subsequent deterioration, an axillary lymph-node was excised. Gomori-Grocott (GG) staining, which was only performed at this stage, revealed the "ship's pilot wheel" appearance. There was no isolation in cultures and serologic and polymerase chain reaction (PCR) testing for Paracoccidioides spp. could not be performed at our hospital. Therefore, the diagnosis of paracoccidioidomycosis was established based on histologic morphology, epidemiologic context, and suggestive clinical features. After the diagnosis was established, the initial slides were reviewed and GG staining was added, becoming clear that the fungal forms were already present in all the tested samples, but had gone unrecognized. Imported fungal infections in non-endemic areas present significant clinical challenges, including delayed diagnosis and limited clinician experience. In Portugal, only one private laboratory can perform PCR and serologic testing for paracoccidioidomycosis. This limitation highlights an important lesson from this case: a diagnosis cannot be made if the disease is not considered. This case may therefore serve as a useful resource for settings with similar diagnostic limitations. Given the extreme rarity of extrapulmonary PCM, this case highlights the need for a comprehensive diagnostic approach to intestinal granulomatous diseases, particularly in patients from endemic regions, and emphasizes the role of internal medicine in this diagnostic process.