Pulmonary histoplasmosis on the Chinese mainland: two case reports and literature review.

INTRODUCTION: Pulmonary histoplasmosis is a fungal disease that is endemic in North and Central America. It is relatively rare in China and commonly misdiagnosed as tuberculosis or cancer due to nonspecific clinical and radiographic manifestations. Rapid and accurate pathogen tests are critical for the diagnosis of pulmonary histoplasmosis. METHODOLOGY: We report two cases of pulmonary histoplasmosis. We collected all the relevant case reports on the Chinese mainland (from 1990 to 2022) to analyze features of this disease among Chinese patients. RESULTS: A total of 42 articles reporting 101 cases were identified, and the two cases reported in this article were also included for analysis. Sixty-three (61.2%) patients had respiratory symptoms and 35 (34.0%) patients were asymptomatic. The most common radiographic findings were pulmonary nodules or masses (81.6%). Twenty-two (21.4%) patients were misdiagnosed as tuberculosis, and 37 (35.9%) were misdiagnosed as lung tumors before pathological findings. Metagenomic next­generation sequencing (mNGS) testing provided a rapid diagnostic and therapeutic basis for three patients. CONCLUSIONS: Clinical features and imaging findings of pulmonary histoplasmosis are not specific. Relevant epidemiological history and timely pathogen detection are important for diagnosis. mNGS can shorten the time required for diagnosis and allow earlier initiation of targeted antibiotic therapy.

Gastrointestinal bleeding in a kidney transplant recipient.

Opportunistic infections are common in transplant recipients, but gastrointestinal bleed is rarely reported to be due to opportunistic fungal infections, and hence could present as a diagnostic challenge. We report a case of disseminated histoplasmosis in a kidney transplant recipient whose initial presentation was acute lower gastrointestinal bleeding with no other symptoms. The colonoscopy showed scattered punchout circular colonic ulcers with biopsy revealing budding yeasts consistent with a diagnosis of histoplasmosis. The patient was successfully treated with a prolonged course of intravenous amphotericin B followed by oral itraconazole.

Pulmonary Histoplasmosis Complicated by Nonvalvular Right Ventricular Wall Histoplasma capsulatum Endocarditis.

Histoplasmosis is commonly a self-limited fungal disease that primarily affects the lung and reticuloendothelial system. Cardiac involvement by histoplasmosis is uncommon. In this report, we provide a detailed description of severe pulmonary histoplasmosis complicated by the disease involvement of the free wall of the right ventricle. A 55-year-old female presented with cough, fevers, dyspnea, and 30-pound unintentional weight loss in 6 months. Her past medical history was significant for supraventricular tachycardia with permanent pacemaker implantation. Imaging studies revealed an intracardiac mass accompanied by mediastinal lymphadenopathy and bilateral lung nodules. Endobronchial ultrasound-guided transbronchial needle aspiration of station 4R lymph nodes revealed numerous yeast forms, morphologically consistent with Histoplasma capsulatum. The diagnosis was further corroborated by the elevated titers of serum antibodies against Histoplasma capsulatum. The right ventricular mass debulking with biopsy showed necrotizing granulomatous inflammation involving nonvalvular endocardium and myocardium of the free wall of the right ventricle. The report documents an unusual presentation of pulmonary histoplasmosis accompanied by nonvalvular endocarditis and suggests a possible association between the site of the cardiac infection and the presence of a permanent intravascular pacer device.

Isolated Colonic Histoplasmosis in Patients Undergoing Immunomodulator Therapy: A Systematic Review.

Gastrointestinal histoplasmosis remains an inconspicuous clinicopathologic entity. It is predominantly considered a protean manifestation of disseminated disease. We hereby delineate a unique case of biopsy-proven isolated colonic histoplasmosis in a patient undergoing methotrexate therapy. Furthermore, we present the first systematic review of the MEDLINE, Google Scholar, Embase, and Scopus databases regarding isolated colonic histoplasmosis in adult patients receiving immunomodulator therapy (IMT). A total of 13 case reports (level of clinical evidence: IV) were identified. The mean age was 55.6 ± 11.1 years, with 9 (69.2%) cases reported in women. Patients with subclinical disease (5, 38.5%) were often incidentally diagnosed by screening colonoscopy. Symptomatic individuals predominantly presented with diarrhea (4, 30.8%), weight loss (3, 23.1%), and/or abdominal pain (3, 23.1%). IMT was mainly administered for liver transplant (4, 30.8%), renal transplant (4, 30.8%), and ulcerative colitis (2, 15.4%). Common colonoscopy features included colonic ulcerations (7, 53.8%), polyps or pseudopolyps (3, 23.1%), and/or mass-like lesions (3, 23.1%). Diagnosis was made by histology of colonic biopsy in 11 (84.6%) and resected specimens in 2 (15.4%) patients. Treatment consisted of a combination of amphotericin B with oral itraconazole in 6 (46.2%), oral itraconazole alone in 5 (38.5%), and amphotericin B alone in 2 (15.4%) patients. Complete clinical recovery was achieved in all patients. This article illustrates that isolated colonic involvement can be the only clinical presentation of histoplasmosis. It may masquerade as other bowel disorders, presenting diagnostic and therapeutic conundrums. Gastroenterologists should rule out colonic histoplasmosis in IMT recipients who develop unexplained colitis symptoms.

Vertebromedular histoplasmosis: About a case of transverse myelitis in a young and immunocompetent adult.

Systemic mycosis raging endemic, histoplasmosis has an increasing incidence with the advent of HIV-AIDS. The authors report a case of vertebra-medullar histoplasmosis mimicking tuberculous spondylodiscitis in a patient without proven immunosuppression. This was a patient who spent 3 years in a highly endemic area. He presented with signs of transverse myelitis. MRI of the lumbar spine showed a para-vertebral tumor lesion that partially infiltrated the spinal cord. The positive diagnosis of histoplasmosis was made by histomorphology, and symptoms were reduced with administration of itraconazole. These findings show the need for a proper coding of the management of patients living or having stayed in histoplasmosis endemic areas, whether they are immunocompromised or not.

Histoplasmosis of the Head and Neck Region Mimicking Malignancy: A Clinic-Pathological Predicament.

OBJECTIVE: Histoplasmosis is a systemic, deep mycotic infection caused by Histoplasma capsulatum. Disseminated histoplasmosis (DH) is synonymous with HIV seropositive immunocompromised individuals; however, isolated histoplasmosis involving the head and neck mucosal sites mimicking malignancy is a clinical predicament. The result, in a superficial biopsy with marked pseudoepitheliomatous hyperplasia (PEH), in a tertiary care cancer center where the number of squamous carcinomas far outnumber the infectious diseases, could be catastrophic. MATERIAL AND METHOD: The archives of a tertiary care cancer hospital were searched (2010-2019) for cases of histoplasmosis involving the head and neck mucosal sites in HIV non-reactive patients. RESULTS: Six cases of isolated head and neck histoplasmosis were seen in biopsies from 4 men and 2 women, with an age range of 46-72 years. Three of these patients suffered from chronic illnesses. The most common site involved was the larynx (vocal cords) in three cases, two cases were involving lips, and one involving the tongue. The biopsies were reviewed in-house with a clinical diagnoses of malignancy in all and an outside biopsy diagnosis of "squamous cell carcinoma" in 2 cases. The important histological findings in the biopsy were PEH (3 cases), granulomas (2 cases), lymphoplasmacytic inflammation (all cases). Eosinophils were conspicuous by their absence. Intracellular histoplasma was seen in all cases, albeit to varying density, which was confirmed with GMS stain. CONCLUSION: A high index of suspicion, meticulous history taking by oncologists, and appropriate distinction of PEH from neoplastic squamous proliferation by pathologists in superficial biopsies and an apropos deeper wedge biopsy are essential to clinch the correct diagnosis.

A case of pulmonary histoplasmosis treated with voriconazole.

Histoplasmosis is an infection caused by the dimorphic fungus Histoplasma capsulatum. The lungs are the most common site of infection, especially in patients with immune deficiency. We report a case of 62-year-old male patient presented with cough for 3 months and had been taking immunosuppressive drugs for 10 years after heart transplantation. Chest CT scan showed multiple pulmonary nodules. Lung tissue biopsy specimen culture suggested fungal infection, and Histoplasma capsulatum was confirmed by next-generation sequencing (NGS) detection. The patient was diagnosed with pulmonary histoplasmosis. After administration of voriconazole for 46 days, the symptom of cough was markedly relieved and the lesions were partly absorbed. After 13 months of treatment, the lesions completely disappeared, and no significant side-effect of voriconazole was observed. To our knowledge, report of voriconazole as the treatment of histoplasmosis is rare, especially in non-endemic areas. Moreover, this case enriches our experience in the adjustment between immunosuppressive and antifungal agents in treating histoplasmosis.

Oral manifestations of systemic fungal infections: 25-year experience in an endemic region

Some mycoses are endemic. They develop through hematogenous spread, causing a generalized infection, usually with secondary mucosal involvement.The aim of this observational and retrospective study was to report the prevalence and characteristics of oral lesions in patients diagnosed with systemic fungal infections (SFI) over a 25-year period in southern Brazil. Demographic (age, sex, ethnicity, occupation) and clinical (anatomical location, symptoms,histopathological diagnosis and management) data from the medical records of patients with SFI were collected from 1995 to 2019. 34 cases of SFI were found, of which 31 (91.18%) were diagnosed as paracoccidioidomycosis (PCM) and 3 (8.82%) as histoplasmosis. Men were much more affected (n = 31; 91.18%), with an average age of 46.9 years. Most patients (n = 18; 58.06%) were Caucasian; 48% (n = 15) were farm/rural workers and the most affected region was the jugal mucosa (n = 13; 25.49%) followed by the alveolar ridge (n = 12; 23.52%). All patients with histoplasmosis were immunocompetent men (mean age: 52.67 years), and the palate was the most affected. All patients underwent incisional biopsy and were referred to an infectologist. The dentist has an essential role in the recognition of SFI, whose oral manifestations may be the first sign. SFI should be included in differential diagnosis in patients from endemic areas. In addition, the inevitable human mobility and globalization make knowledge of these mycosesnecessary worldwide, especially since advanced cases in immunocompromised patients can be fatal.

Histoplasma capsulatum var. duboisii: A KwaZulu-Natal, South Africa public sector perspective.

BACKGROUND: Histoplasma capsulatum var. duboisii (H. duboisii) causes potentially fatal disease in the immunocompromised patient, and the literature on these cases is limited. The study was undertaken to describe the cases of H. duboisii seen in a resource-limited setting. METHODS: A 5-year retrospective, laboratory-based histopathologic review of all H. duboisii cases. RESULTS: A total of 24 patients were diagnosed with cutaneous H. duboisii infection. The male-to-female ratio was 1.4. All the patients were human immunodeficiency virus (HIV) positive, and 70.83% (17 of 24 patients) were on antiretroviral therapy. The clinically identified lesions were as follows: plaques, nodular plaques, papules, papulo-pustules, and umbilicated papules. Histopathological appraisal revealed organisms typical of H. duboisii. The commonest epidermal alterations were interface change, parakeratosis, spongiosis, ulceration, acanthosis, hyperkeratosis, transepidermal elimination, and exocytosis in decreasing order. The dermal changes included histiocytic pattern (n = 14), neutrophil-rich (n = 13), non-necrotizing granulomatous inflammation (n = 9), and karyorrhexis (n = 6). Histoplasma was confirmed in 53% (8 of 15 samples) of the tissue samples submitted for routine fungal culture. CONCLUSION: This study showed the demographics, clinical and histopathology features of H. duboisii infection in a resource-limited setting. Further research on histopathological features of this rare infection is essential to expand on the knowledge base and support findings in this study.

Isolated gastrointestinal histoplasmosis: A rare diagnosis of pediatric chronic abdominal pain.

Gastrointestinal (GI) histoplasmosis usually occurs as a part of disseminated histoplasmosis in immunocompromised or elderly subjects. Isolated histoplasmosis involving the GI tract in an immunocompetent host is very rare. It is also not considered as an etiology for chronic abdominal pain in children. Here we present an 8-year-old boy with abdominal pain and weight loss who underwent treatment for tuberculosis but on reinvestigation was diagnosed as GI histoplasmosis. He responded well to treatment and achieved good catch up growth.

Mucocutaneous nasal histoplasmosis in an immunocompetent dog.

BACKGROUND: Histoplasma (H.) capsulatum is a dimorphic fungus, and infection is typically via inhalation of microconidia. After conversion to the yeast phase within the lung, the organism is subsequently disseminated to other tissues by macrophages. Nasal histoplasmosis appears to be a rare condition in dogs. CASE PRESENTATION: We report the clinical case of a 4.5-year-old male neutered Cocker spaniel/Poodle mix, 7.7 kg, body condition score 6/9, that presented with a 3-month history of sneezing and left-sided mucoid nasal discharge. The history also included a mild swelling (transient) of the right carpus with a lameness (grade II-III/IV), coinciding with the onset of sneezing and nasal discharge. The dog lived primarily indoors in the Texas Gulf Coast area. On physical examination, the dog was febrile, and the left nostril was swollen, ulcerative, deformed, and hypopigmented. Mandibular lymph nodes were firm and mildly enlarged bilaterally. Mild lymphopenia, thrombocytopenia, and hyperglobulinemia were noted. Thoracic radiographs were unremarkable. Computed tomography and rhinoscopy revealed swelling of the rostral portion of the left and right nasal passages. Cytology and histology of biopsies of the affected nasal tissue showed pyogranulomatous inflammation and yeast organisms consistent with H. capsulatum. Weak antigenuria was detected on the MVista H. capsulatum antigen test. Treatment with oral itraconazole led to a resolution of the nasal signs and normalization of the appearance of the nostril over 13 weeks, and neither antigenuria nor antigenemia was detected on several recheck examinations. The dog remained in good general and physical condition and showed no signs of disease recurrence more than 6 years after the last examination. CONCLUSION: We report a rare case of nasal mucocutaneous histoplasmosis in an immunocompetent dog, with an excellent clinical response to oral itraconazole. This case documents that histoplasmosis in dogs can affect primarily the nasal cavity, which responds rapidly to triazole antifungal therapy and has a good prognosis. A similar case has only been reported in human medicine in a young adult.

High prevalence and mortality due to Histoplasma capsulatum in the Brazilian Amazon: An autopsy study.

BACKGROUND: Histoplasmosis is acquired by inhalation of spores of the dimorphic fungus Histoplasma spp. Although this pathogen is distributed worldwide, it is more prevalent in the Americas. However, the real burden of histoplasmosis remains undefined in many endemic regions. METHODOLOGY: We conducted a series of 61 autopsies to individuals who died in a hospital in the Brazilian Amazon focused on infectious diseases. We performed a detailed histological and microbiological evaluation with genetic characterization of Histoplasma strains with the aim to evaluate the contribution of histoplasmosis to morbidity and mortality. Additionally, we assessed the clinicopathological correlation. PRINCIPAL FINDINGS: Evidence of Histoplasma infection was detected in 21 patients (34%). Eight cases were disseminated infections, all of them occurred in HIV-positive patients. Six cases were localized histoplasmosis, limited to the lungs. In seven patients Histoplasma DNA was detected by PCR in patients with no histological lesions. Histoplasma infection was detected in 38% of HIV-positive patients and was a major contributor to death in 22% of them. Lungs, liver and spleen were affected in all cases of disseminated histoplasmosis. Phylogenetic analysis of the strains suggested a high diversity of Histoplasma species circulating in the Brazilian Amazon. Histoplasmosis was clinically missed in 75% of the disseminated infections. CONCLUSIONS: The high incidence of histoplasmosis, the low index of clinical suspicion, and the severity of the disseminated disease highlight the need of proactively implementing sensitive routine screening methods for this pathogen in endemic areas. Antifungal prophylaxis against Histoplasma should be encouraged in the severely immunocompromised HIV patients in these areas. In conclusion, substantial mortality is associated with disseminated histoplasmosis among HIV-positive patients in the Brazilian Amazon.

Cutaneous Histoplasmosis in HIV Seronegative Patients: A Clinicopathological Analysis.

BACKGROUND: Diagnosis of extrapulmonary histoplasmosis in HIV seronegative and immunocompetent patients is often challenging, so a high index of suspicion is required. Cutaneous manifestation of infection shows a wide spectrum of lesions including erythematous plaques; maculopapules; crusted, verrucous, or desquamative papules and nodules; abscesses; and mucocutaneous ulcers among others. Due to the variations in its clinical presentation, histopathology plays a very important role in the detection of spores and the confirmation of diagnosis. OBJECTIVES: The aim of our study was to analyze clinicopathological characteristics of cutaneous manifestations of biopsy-proven histoplasmosis in HIV seronegative individuals. We also examined the utility of Fite stain for the diagnosis of Histoplasma capsulatum on tissue biopsy sections. METHODS: This was a retrospective, observational study on 7 patients who were HIV seronegative and clinically manifested with isolated cutaneous lesions or disseminated disease. Skin biopsy from the lesions was performed on all 7 patients. In addition to H&E staining and special stains for detecting fungus, Fite staining was performed on all of the cases to study its utility in detecting H. capsulatum spores. RESULTS: The skin lesions were widely disseminated in all patients and the most common cutaneous lesions were papules, present in all 7 patients. On review of the H&E-stained slides, the most common pattern was histiocytic lobular panniculitis-like infiltrate observed in 4 cases. Fite stain highlighted the yeast as magenta-colored spores on a blue background in all cases, except for 1 with a granulomatous pattern. CONCLUSION: A primary cutaneous manifestation of H. capsulatum infection in non-HIV-infected individuals is extremely rare. Fite stain could aid in differentiating the spores of H. capsulatum from those of other fungi, Cryptococcus and Candida in particular.

Clinical Significance and Histologic Characterization of Histoplasma Granulomas.

OBJECTIVES: To clarify the clinical significance and degree of resolution (ie, grade) of Histoplasma granulomas in routinely reviewed surgical pathology specimens and the clinical outcomes of patients with this diagnosis, with an emphasis on those not receiving antifungal therapy. METHODS: We performed a retrospective medical record, laboratory data, and surgical pathology slide review of patients with Histoplasma granulomas following institutional review board approval. RESULTS: Clinical, pathologic, and laboratory data from 62 patients with Histoplasma granulomas were available for review. Of these, 1 of 19 (5%) fungal cultures, 4 of 12 (33%) fungal serologic studies, 0 of 9 Histoplasma urinary antigen tests, and 0 of 2 Histoplasma serum antigen tests were positive. All but 3 of the Histoplasma granulomas were either in the resolving (grade 2) or resolved (grade 3) stage of resolution. None of the patients, including those who did not receive antifungal therapy after the histologic diagnosis, developed progressive or disseminated histoplasmosis. CONCLUSIONS: These findings, which are supportive of clinical guidelines, suggest that patients with old, hyalinized Histoplasma granulomas do not benefit from further laboratory studies or antifungal therapy. The proposed grading of Histoplasma granulomas informs clinicians of the stage of resolution of an excised lesion, which informs therapeutic decisions and thus is recommended.