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.

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.

Pulmonary Mycosis Drives Forkhead Box Protein A2 Degradation and Mucus Hypersecretion through Activation of the Spleen Tyrosine Kinase-Epidermal Growth Factor Receptor-AKT/Extracellular Signal-Regulated Kinase 1/2 Signaling.

Pulmonary mycoses are difficult to treat and detrimental to patients. Fungal infections modulate the lung immune response, induce goblet cell hyperplasia and metaplasia, and mucus hypersecretion in the airways. Excessive mucus clogs small airways and reduces pulmonary function by decreasing oxygen exchange, leading to respiratory distress. The forkhead box protein A2 (FOXA2) is a transcription factor that regulates mucus homeostasis in the airways. However, little is known whether pulmonary mycosis modulates FOXA2 function. Herein, we investigated whether Blastomyces dermatitidis and Histoplasma capsulatum-infected canine and feline lungs and airway epithelial cells could serve as higher animal models to examine the relationships between fungal pneumonia and FOXA2-regulated airway mucus homeostasis. The results indicate that fungal infection down-regulated FOXA2 expression in airway epithelial cells, with concomitant overexpression of mucin 5AC (MUC5AC) and mucin 5B (MUC5B) mucins. Mechanistic studies reveal that B. dermatitidis infection, as well as ß-glucan exposure, activated the Dectin-1-SYK-epidermal growth factor receptor-AKT/extracellular signal-regulated kinase 1/2 signaling pathway that inhibits the expression of FOXA2, resulting in overexpression of MUC5AC and MUC5B in canine airway cells. Further understanding of the role of FOXA2 in mucus hypersecretion may lead to novel therapeutics against excessive mucus in both human and veterinary patients with pulmonary mycosis.

Unique Oral Presentations of Deep Fungal Infections: A Report of Four Cases.

Deep fungal infections rarely involve the oral cavity and most commonly affect immunocompromised patients. Oral deep fungal infections typically manifest as chronic mucosal ulcerations or granular soft tissue overgrowths. Since these lesions are non-specific and can mimic malignancy, it is crucial to obtain a thorough clinical history and an adequate biopsy to render the appropriate diagnosis. We report four new cases of deep fungal infections, diagnosed as histoplasmosis, blastomycosis and chromoblastomycosis, exhibiting unique oral and perioral presentations. Awareness of these unusual entities can help dental and medical practitioners expedite proper multidisciplinary care and minimize morbidity and mortality.

Ultrasonographic findings of gastrointestinal histoplasmosis in dogs.

Histoplasmosis, a mycotic infection caused by Histoplasma spp, can infect the gastrointestinal tract of dogs. Clinical signs of gastrointestinal histoplasmosis can include diarrhea, profound weight loss, anorexia, and vomiting. Rectal scrape for cytology can provide a quick diagnosis, but if negative abdominal ultrasound is often pursued. Ultrasonographic abnormalities in dogs with gastrointestinal histoplasmosis have rarely been reported. This retrospective, single-center case series aimed to describe the ultrasonographic features of gastrointestinal histoplasmosis in dogs. Nineteen cases with a diagnosis of gastrointestinal histoplasmosis confirmed with gastrointestinal cytology or histopathology (N = 15) or gastrointestinal lymph node cytology (N = 4) that had undergone an abdominal ultrasound examination from 2005 to 2020 were included. Ultrasound images were reviewed by an American College of Veterinary Radiology (ACVR)-certified veterinary radiologist and diagnostic imaging resident. Eighteen cases had sonographic abnormalities within the gastrointestinal tract. The colon was the most affected organ. Colonic thickening and abnormal wall layering were the most frequent findings (N = 16 dogs); thickening ranged from 0.36 to 1.2 cm. Diffuse, multifocal, and focal thickening patterns were seen. Sixteen patients had abnormal wall layering of the colon (complete loss of layering or altered with partial loss of layering). Other frequent findings included lymphadenopathy, small intestinal thickening with abnormal wall layering and peritoneal effusion. Based on the authors' review of the literature, this is the first description of ultrasonographic findings of gastrointestinal histoplasmosis in a group of dogs. Although abnormal gastrointestinal wall layering seen sonographically is most frequently associated with neoplasia, this is not pathognomonic. Gastrointestinal histoplasmosis should be considered as a differential diagnosis due to the similarities and overlap of ultrasonographic features.

[Ileocolitis in an immunocompromised patient. Crohn's disease or an infection?] / Ileocolitis bij een immuungecompromitteerde patiënte.

BACKGROUND: Histoplasma capsulatum is an endemic fungus in especially tropical areas. While mostly asymptomatic, histoplasmosis can be life-threatening in immunocompromised patients. CASE DESCRIPTION: A 60-year-old woman of Suriname origin, with a history of renal transplantation and use of mycophenolate mofetil and prednisone, presented with abdominal pain and diarrhea. Colonoscopy revealed ulcerative ileocolitis and biopsy showed active granulomatous inflammation. Morbus Crohn was considered the most plausible diagnosis after ruling out several infectious and pharmacological causes. Despite prednisone treatment, symptoms persisted and infliximab was initiated. The patient developed constitutional symptoms and radiological examination revealed disseminated granulomatous disease. Liver biopsy and re-evaluation of previous intestinal histopathology confirmed suspected histoplasmosis. CONCLUSION: Histoplasmosis should be considered in immunocompromised patients with ileocolitis who have been in endemic regions (South America). Physicians need to assess the risk of previous exposure to histoplasmosis before starting anti-TNF-α therapy.

Clinical and Morphological Spectrum of Histoplasmosis on Cytology Along with the Review of Literature.

OBJECTIVE: The aim of the study was to study the clinical and morphological spectrum of histoplasmosis diagnosed by fine needle aspiration cytology (FNAC). STUDY DESIGN: A total of 17 patients diagnosed with histoplasmosis on FNAC were studied over a period of 5 years. The cytology smears were studied and analysed for the cytomorphological spectrum of histoplasmosis. RESULTS: Among the 17 patients studied, the mean age was 51.3 years (range 6-84 years). Male-to-female ratio was 3.25:1 with 4 females and 13 males. The frequent sites of involvement were the lung (5), lymph node (4), adrenal gland (4), and skin (4). The most common cytological patterns were histiocytic collection, followed by granulomas and multinucleated giant cells. Necrosis was noted in only 4 cases. CONCLUSION: Fine needle aspiration is a highly accurate, rapid, and cheap technique for the diagnosis of histoplasmosis due to its distinct morphological features.