Antifungal drug penetration in soft tissue abscesses: a comparative analysis.

BACKGROUND: Invasive fungal infections (IFIs) are severe and difficult-to-treat infections affecting immunocompromised patients. Antifungal drug penetration at the site of infection is critical for outcome and may be difficult to achieve. Data about antifungal drug distribution in infected human tissues under real circumstances of IFI are scarce. METHODS: Multiple samples were obtained from soft tissue abscesses of a lung transplant patient with Candida albicans invasive candidiasis who underwent recurrent procedures of drainage, while receiving different consecutive courses of antifungal therapy [itraconazole (ITC), fluconazole, caspofungin]. Antifungal drug concentrations were measured simultaneously at the site of infection (surrounding inflammatory tissue and fluid content of the abscess) and in plasma for calculation of the tissue/plasma ratio (R). The concentration within the infected tissue was interpreted as appropriate if it was equal or superior to the MIC of the causal pathogen. RESULTS: A total of 30 tissue samples were collected for measurements of ITC (n = 12), fluconazole (n = 17) and caspofungin (n = 1). Variable concentrations were observed in the surrounding tissue of the lesions with median R of 2.79 (range 0.51-15.9) for ITC and 0.94 (0.21-1.37) for fluconazole. Concentrations ranges within the fluid content of the abscesses were 0.39-1.83 for ITC, 0.66-1.02 for fluconazole and 0.23 (single value) for caspofungin. The pharmacodynamic target (tissue concentration ≥ MIC) was achieved in all samples for all three antifungal drugs. CONCLUSIONS: This unique dataset of antifungal drug penetration in infected human soft tissue abscesses suggests that ITC, fluconazole and caspofungin could achieve appropriate concentrations in soft tissue abscesses.

Clinicopathologic conference: Bloodstream infection in an allogeneic hamatopoietic cell transplant: Thinking beyond the usual.

This case involves a 53-year-old female with concurrent acute myeloid leukemia (AML) and multiple myeloma. She underwent cytarabine and daunorubicin (7+3) induction chemotherapy followed by cytarabine (HiDAC) consolidation, with an early AML relapse requiring azacitidine and venetoclax therapy. She achieved complete remission and incomplete count recovery. Following fludarabine, melphalan, and thymoglobulin induction chemotherapy, she underwent an allogeneic stem cell transplant with failure to engraft, requiring autologous stem cell rescue, buffy coat, and granulocyte transfusions, eventually presenting with a diffuse skin rash consistent with Steven-Johnson syndrome and toxic epidermal necrolysis, persistent neutropenic fevers and positive blood cultures.

Antifungal Treatment Duration in Hematology Patients With Invasive Mold Infections: A Real-life Update.

Background: Limited data exist on when and how to stop antifungal treatment (AFT) in patients with invasive mold infections (IMIs) who are immunocompromised. Methods: This retrospective multicenter study included adult patients with acute myelogenous leukemia and proven/probable IMI (1 January 2010-31 December 2022) in 3 university hospitals. The primary objective was to describe AFT duration and adaptation. Secondary objectives were to investigate the reasons for AFT adjustments and prolongation. Results: In total 71 patients with 73 IMIs were identified; 51 (71.8%) had an allogeneic hematopoietic cell transplant. Most infections were invasive aspergillosis (IA; 49/71, 69%), followed by mucormycosis (12, 16.9%) and other (12, 16.9%); there were 2 mixed infections. Median treatment duration was 227 days (IQR, 115.5-348.5). There was no difference in AFT duration between patients with IA and non-IA IMI (P = .85) or by center (P = .92). Treatment was longer in patients with an allogeneic hematopoietic cell transplant vs not (P = .004). Sixteen patients (22.5%) had no therapy modifications. In 55 patients (77.5%), a median 2 changes (IQR, 1-3; range, 1-8) were observed. There were 182 reasons leading to 165 changes, associated with clinical efficacy (82/182, 44.5%), toxicity (47, 25.8%), and logistical reasons (22, 12.1%); no reason was documented in 32 changes (18.8%). AFT was continued beyond days 90 and 180 in 59 (83%) and 39 (54.9%) patients, respectively, mostly due to persistence of immunosuppression. Conclusions: AFT in patients with acute myelogenous leukemia and IMI is longer than that recommended by guidelines and is frequently associated with treatment adjustments due to variable reasons. More data and better guidance are required to optimize AFT duration and secondary prophylaxis administration according to immunosuppression.

Isavuconazole for the Treatment of Fungal Infections: A Real-life Experience From the Fungal Infection Network of Switzerland (FUNGINOS).

This analysis of 116 isavuconazole therapy courses shows that hepatic test disturbances (HTDs) were relatively frequent (29% of cases) but rarely led to treatment interruption (5%). Importantly, patients with baseline HTDs, including those attributed to a first-line triazole, did not exhibit a higher risk of subsequent HTD under isavuconazole therapy.

Novel antifungals and treatment approaches to tackle resistance and improve outcomes of invasive fungal disease.

SUMMARYFungal infections are on the rise, driven by a growing population at risk and climate change. Currently available antifungals include only five classes, and their utility and efficacy in antifungal treatment are limited by one or more of innate or acquired resistance in some fungi, poor penetration into "sequestered" sites, and agent-specific side effect which require frequent patient reassessment and monitoring. Agents with novel mechanisms, favorable pharmacokinetic (PK) profiles including good oral bioavailability, and fungicidal mechanism(s) are urgently needed. Here, we provide a comprehensive review of novel antifungal agents, with both improved known mechanisms of actions and new antifungal classes, currently in clinical development for treating invasive yeast, mold (filamentous fungi), Pneumocystis jirovecii infections, and dimorphic fungi (endemic mycoses). We further focus on inhaled antifungals and the role of immunotherapy in tackling fungal infections, and the specific PK/pharmacodynamic profiles, tissue distributions as well as drug-drug interactions of novel antifungals. Finally, we review antifungal resistance mechanisms, the role of use of antifungal pesticides in agriculture as drivers of drug resistance, and detail detection methods for antifungal resistance.

Investigations of an increased incidence of non-Aspergillus invasive mould infections in an onco-haematology unit.

AIMS OF THE STUDY: Invasive mould infections are life-threatening complications in patients with haematologic cancer and chemotherapy-induced neutropenia. While invasive aspergillosis represents the main cause of invasive mould infections, non-Aspergillus mould infections, such as mucormycosis, are increasingly reported. Consequently, their local epidemiology should be closely monitored. The aim of this study was to investigate the causes of an increased incidence of non-Aspergillus mould infections in the onco-haematology unit of a Swiss tertiary care hospital. METHODS: All cases of proven and probable invasive mould infections were retrospectively identified via a local registry for the period 2007-2021 and their incidence was calculated per 10,000 patient-days per year. The relative proportion of invasive aspergillosis and non-Aspergillus mould infections was assessed. Factors that may affect invasive mould infections' incidence, such as antifungal drug consumption, environmental contamination and changes in diagnostic approaches, were investigated. RESULTS: A significant increase of the incidence of non-Aspergillus mould infections (mainly mucormycosis) was observed from 2017 onwards (Mann and Kendall test p = 0.0053), peaking in 2020 (8.62 episodes per 10,000 patient-days). The incidence of invasive aspergillosis remained stable across the period of observation. The proportion of non-Aspergillus mould infections increased significantly from 2017 (33% vs 16.8% for the periods 2017-2021 and 2007-2016, respectively, p = 0.02). Building projects on the hospital site were identified as possible contributors of this increase in non-Aspergillus mould infections. However, novel diagnostic procedures may have improved their detection. CONCLUSIONS: We report a significant increase in non-Aspergillus mould infections, and mainly in mucormycosis infections, since 2017. There seems to be a multifactorial origin to this increase. Epidemiological trends of invasive mould infections should be carefully monitored in onco-haematology units in order to implement potential corrective measures.

Serial monitoring of pancreatic stone protein for the detection of sepsis in intensive care unit patients with complicated abdominal surgery: A prospective, longitudinal cohort study.

PURPOSE: The objective of this study was to assess the performance of pancreatic stone protein (PSP) monitoring for the detection of sepsis, prediction of outcome and distinction between bacterial and fungal infections in intensive care unit (ICU) patients with complicated abdominal surgery. MATERIALS AND METHODS: In this prospective multicenter cohort study, patients with complicated abdominal surgery had serial PSP measurements during their ICU stay. Infectious episodes were classified as bacterial, fungal or mixed. PSPmax (maximal PSP value within 48 h of the diagnosis of infection) and ΔPSP (difference between PSPmax and the preceding PSP value) were used for analyses. RESULTS: PSPmax was obtained for 118 infectious episodes (68 patients). ΔPSP was available for 73 episodes (48 patients). Both PSPmax and ΔPSP were significantly higher in patients with sepsis and in patients with a fatal outcome. A PSPmax ≥124 ng/ml and a ΔPSP ≥34 ng/ml could detect sepsis with a sensitivity/specificity of 84%/54% and 69%/76%, respectively. There was no significant difference of PSPmax or ΔPSP between patients with bacterial/mixed versus fungal infections. CONCLUSIONS: Serial PSP monitoring may be an additional tool for the early detection of sepsis in patients with complicated abdominal surgery who are at high risk of severe infections.

Role of source control in critically ill candidemic patients: a multicenter retrospective study.

PURPOSE: Candidemia is associated with high mortality especially in critically ill patients. Our aim was to identify predictors of mortality among critically ill patients with candidemia with a focus on early interventions that can improve prognosis. METHODS: Multicenter retrospective study. SETTING: This retrospective study was conducted in Intensive Care Units from three European university hospitals from 2015 to 2021. Adult patients with at least one positive blood culture for Candida spp. were included. Patients who did not require source control were excluded. Primary outcome was 14-day mortality. RESULTS: A total of 409 episodes of candidemia were included. Most candidemias were catheter related (173; 41%), followed by unknown origin (170; 40%). Septic shock developed in 43% episodes. Overall, 14-day mortality rate was 29%. In Cox proportional hazards regression model, septic shock (P 0.001; HR 2.20, CI 1.38-3.50), SOFA score ≥ 10 points (P 0.008; HR 1.83, CI 1.18-2.86), and prior SARS-CoV-2 infection (P 0.003; HR 1.87, CI 1.23-2.85) were associated with 14-day mortality, while combined early appropriate antifungal treatment and source control (P < 0.001; HR 0.15, CI 0.08-0.28), and early source control without appropriate antifungal treatment (P < 0.001; HR 0.23, CI 0.12-0.47) were associated with better survival compared to those without neither early appropriate antifungal treatment nor source control. CONCLUSION: Early source control was associated with better outcome among candidemic critically ill patients.

Invasive Fungal Diseases in Adult Patients in Intensive Care Unit (FUNDICU): 2024 consensus definitions from ESGCIP, EFISG, ESICM, ECMM, MSGERC, ISAC, and ISHAM.

PURPOSE: The aim of this document was to develop standardized research definitions of invasive fungal diseases (IFD) in non-neutropenic, adult patients without classical host factors for IFD, admitted to intensive care units (ICUs). METHODS: After a systematic assessment of the diagnostic performance for IFD in the target population of already existing definitions and laboratory tests, consensus definitions were developed by a panel of experts using the RAND/UCLA appropriateness method. RESULTS: Standardized research definitions were developed for proven invasive candidiasis, probable deep-seated candidiasis, proven invasive aspergillosis, probable invasive pulmonary aspergillosis, and probable tracheobronchial aspergillosis. The limited evidence on the performance of existing definitions and laboratory tests for the diagnosis of IFD other than candidiasis and aspergillosis precluded the development of dedicated definitions, at least pending further data. The standardized definitions provided in the present document are aimed to speed-up the design, and increase the feasibility, of future comparative research studies.

PCR diagnostic platforms for non-Aspergillus mold infections: ready for routine implementation in the clinic?

INTRODUCTION: While Aspergillus spp. remain the predominant cause of invasive mold infections, non-Aspergillus molds, such as the Mucorales or Fusarium spp., account for an increasing proportion of cases. The diagnosis of non-Aspergillus invasive mold infections (NAIMI) is challenging because of the low sensitivity and delay of conventional microbiological tests. Therefore, there is a particular interest to develop molecular tools for their early detection in blood or other clinical samples. AREAS COVERED: This extensive review of the literature discusses the performance of Mucorales-specific PCR and other genus-specific or broad-range fungal PCR that can be used for the diagnosis of NAIMI in diverse clinical samples, with a focus on novel technologies. EXPERT OPINION: PCR currently represents the most promising approach, combining good sensitivity/specificity and ability to detect NAIMI in clinical samples before diagnosis by conventional cultures and histopathology. Several PCR assays have been designed for the detection of Mucorales in particular, but also Fusarium spp. or Scedosporium/Lomentospora spp. Some commercial Mucorales PCRs are now available. While efforts are still needed for standardized protocols and the development of more rapid and simpler techniques, PCR is on the way to becoming an essential test for the early diagnosis of mucormycosis and possibly other NAIMIs.

Upc2-mediated mechanisms of azole resistance in Candida auris.

Candida auris is an emerging yeast pathogen of major concern because of its ability to cause hospital outbreaks of invasive candidiasis and to develop resistance to antifungal drugs. A majority of C. auris isolates are resistant to fluconazole, an azole drug used for the treatment of invasive candidiasis. Mechanisms of azole resistance are multiple, including mutations in the target gene ERG11 and activation of the transcription factors Tac1b and Mrr1, which control the drug transporters Cdr1 and Mdr1, respectively. We investigated the role of the transcription factor Upc2, which is known to regulate the ergosterol biosynthesis pathway and azole resistance in other Candida spp. Genetic deletion and hyperactivation of Upc2 by epitope tagging in C. auris resulted in drastic increases and decreases in susceptibility to azoles, respectively. This effect was conserved in strains with genetic hyperactivation of Tac1b or Mrr1. Reverse transcription PCR analyses showed that Upc2 regulates ERG11 expression and also activates the Mrr1/Mdr1 pathway. We showed that upregulation of MDR1 by Upc2 could occur independently from Mrr1. The impact of UPC2 deletion on MDR1 expression and azole susceptibility in a hyperactive Mrr1 background was stronger than that of MRR1 deletion in a hyperactive Upc2 background. While Upc2 hyperactivation resulted in a significant increase in the expression of TAC1b, CDR1 expression remained unchanged. Taken together, our results showed that Upc2 is crucial for azole resistance in C. auris, via regulation of the ergosterol biosynthesis pathway and activation of the Mrr1/Mdr1 pathway. Notably, Upc2 is a very potent and direct activator of Mdr1.IMPORTANCECandida auris is a yeast of major medical importance causing nosocomial outbreaks of invasive candidiasis. Its ability to develop resistance to antifungal drugs, in particular to azoles (e.g., fluconazole), is concerning. Understanding the mechanisms of azole resistance in C. auris is important and may help in identifying novel antifungal targets. This study shows the key role of the transcription factor Upc2 in azole resistance of C. auris and shows that this effect is mediated via different pathways, including the regulation of ergosterol biosynthesis and also the direct upregulation of the drug transporter Mdr1.

Lung and sinus fungal infection imaging in immunocompromised patients.

BACKGROUND: Imaging is a key diagnostic modality for suspected invasive pulmonary or sinus fungal disease and may help to direct testing and treatment. Fungal diagnostic guidelines have been developed and emphasize the role of imaging in this setting. We review and summarize evidence regarding imaging for fungal pulmonary and sinus disease (in particular invasive aspergillosis, mucormycosis and pneumocystosis) in immunocompromised patients. OBJECTIVES: We reviewed data on imaging modalities and findings used for diagnosis of invasive fungal pulmonary and sinus disease. SOURCES: References for this review were identified by searches of PubMed, Google Scholar, Embase and Web of Science through 1 April 1 2023. CONTENT: Computed tomography imaging is the method of choice for the evaluation of suspected lung or sinus fungal disease. Although no computed tomography radiologic pattern is pathognomonic of pulmonary invasive fungal disease (IFD) the halo sign firstly suggests an angio-invasive pulmonary aspergillosis while the Reversed Halo Sign is more suggestive of pulmonary mucormycosis in an appropriate clinical setting. The air crescent sign is uncommon, occurring in the later stages of invasive aspergillosis in neutropenic patients. In contrast, new cavitary lesions should suggest IFD in moderately immunocompromised patients. Regarding sinus site, bony erosion, peri-antral fat or septal ulceration are reasonably predictive of IFD. IMPLICATIONS: Imaging assessment of the lung and sinuses is an important component of the diagnostic work-up and management of IFD in immunocompromised patients. However, radiological features signs have sensitivity and specificity that often vary according to underlying disease states. Periodic review of imaging studies and diagnostic guidelines characterizing imaging findings may help clinicians to consider fungal infections in clinical care thereby leading to an earlier confirmation and treatment of IFD.

Occurrence of Aspergillus fumigatus azole resistance in soils from Switzerland.

Aspergillus fumigatus is a fungal species causing diverse diseases in humans. The use of azoles for treatments of A. fumigatus diseases has resulted in azole resistance. Azoles are also widely used in the environment for crop protection, which resulted in azole resistance. Resistance is primarily due to mutations in cyp51A, which encodes the target protein for azoles. Here we addressed the occurrence of azole resistance in soils from a vast part of Switzerland. We aimed to associate the use of azoles in the environment with the occurrence of azole resistance. We targeted sample sites from different agricultural environments as well as sites with no agricultural practice (natural sites and urban sites). Starting from 327 sites, 113 A. fumigatus isolates were recovered (2019-2021), among which 19 were azole-resistant (15 with TR34/L98H and four with TR46/Y121F/T289A resistance mutations in cyp51A). Our results show that azole resistance was not associated with a specific agricultural practice. Azoles could be chemically detected in investigated soils, however, their presence was not associated with the occurrence of azole-resistant isolates. Interestingly, genetic markers of resistance to other fungicides were detected but only in azole-resistant isolates, thus reinforcing the notion that A. fumigatus cross-resistance to fungicides has an environmental origin. In conclusion, this study reveals the spreading of azole resistance in A. fumigatus from the environment in Switzerland. The proximity of agricultural areas to urban centers may facilitate the transmission of resistant strains to at-risk populations. Thus, vigilant surveillance is required to maintain effective treatment options for aspergillosis.

Aspergillus fumigatus is ubiquitous and causes diseases in humans. Antifungal drugs, and especially azoles, are used to combat A. fumigatus. Azoles are widely used in the environment, which exposes A. fumigatus and results in azole resistance. Azole resistance was investigated in Switzerland.

Atypical imaging patterns during lung invasive mould diseases: lessons for clinicians.

Imaging of pulmonary invasive mould diseases (IMDs), which represents a cornerstone in their work-up, is mainly based on computed tomography (CT). The purpose of this review is to discuss their CT features, mainly those related to aspergillosis and mucormycosis. We will especially focus on atypical radiological presentations that are increasingly observed among non-neutropenic emerging populations of patients at risk, such as those receiving novel anticancer therapies or those in the intensive care unit. We will also discuss the interest of other available imaging techniques, mainly positron emission tomography/CT, that may play a role in the diagnosis as well as evaluation of disease extent and follow-up. We will show that any new airway-centred abnormality or caveated lesion should evoke IMDs in mildly immunocompromised hosts. Limitations in their recognition may be due to potential underlying abnormalities that increase the complexity of interpretation of lung imaging, as well as the non-specificity of imaging features. In this way, the differentials of all morphological/metabolic aspects must be kept in mind for the optimal management of patients, as well as the benefit of evaluation of the vascular status.

Novel Approaches in the Management of Mucormycosis.

Purpose of Review: Invasive mucormycosis (IM), caused by fungi of the order Mucorales, is one of the deadliest fungal infection among hematologic cancer patients. Its incidence is also increasingly reported in immunocompetent individuals, notably with the COVID-19 pandemic. Therefore, there is an urgent need for novel diagnostic and therapeutic approaches of IM. This review discusses the current advances in this field. Recent Findings: Early diagnosis of IM is crucial and can be improved by Mucorales-specific PCR and development of lateral-flow immunoassays for specific antigen detection. The spore coat proteins (CotH) are essential for virulence of the Mucorales and may represent a target for novel antifungal therapies. Adjuvant therapies boosting the immune response, such as interferon-γ, anti-PDR1 or fungal-specific chimeric antigen receptor (CAR) T-cells, are also considered. Summary: The most promising perspectives for improved management of IM consist of a multilayered approach targeting both the pathogen and the host immune system.

Performance of the beta-glucan test for the diagnosis of invasive fusariosis and scedosporiosis: a meta-analysis.

The (1→3)-ß-D-glucan (BDG) is a component of the fungal cell wall that can be detected in serum and used as an adjunctive tool for the diagnosis of invasive mold infections (IMI) in patients with hematologic cancer or other immunosuppressive conditions. However, its use is limited by modest sensitivity/specificity, inability to differentiate between fungal pathogens, and lack of detection of mucormycosis. Data about BDG performance for other relevant IMI, such as invasive fusariosis (IF) and invasive scedosporiosis/lomentosporiosis (IS) are scarce. The objective of this study was to assess the sensitivity of BDG for the diagnosis of IF and IS through systematic literature review and meta-analysis. Immunosuppressed patients diagnosed with proven or probable IF and IS, with interpretable BDG data were eligible. A total of 73 IF and 27 IS cases were included. The sensitivity of BDG for IF and IS diagnosis was 76.7% and 81.5%, respectively. In comparison, the sensitivity of serum galactomannan for IF was 27%. Importantly, BDG positivity preceded the diagnosis by conventional methods (culture or histopathology) in 73% and 94% of IF and IS cases, respectively. Specificity was not assessed because of lacking data. In conclusion, BDG testing may be useful in patients with suspected IF or IS. Combining BDG and galactomannan testing may also help differentiating between the different types of IMI.

IF and IS are severe fungal infections for which diagnosis is often delayed. This meta-analysis shows that beta-glucan testing in serum had a sensitivity of about 80% for IF/IS and could detect the disease earlier compared to conventional diagnostic tests.

Clinically relevant bidirectional drug-drug interaction between midostaurin and voriconazole.

Midostaurin is often prescribed with azole antifungals in patients with leukaemia, either for aspergillosis prophylaxis or treatment. Midostaurin is extensively metabolized by cytochrome (CYP) 3A4. In addition, it inhibits and induces various CYPs at therapeutic concentrations. Thus, midostaurin is associated with a high potential for drug-drug interactions (DDIs), both as a substrate (victim) and as a perpetrator. However, data on midostaurin as a perpetrator of DDIs are scarce, as most pharmacokinetic studies have focused on midostaurin as a victim drug. We report a clinically relevant bidirectional DDI between midostaurin and voriconazole during induction treatment. A 49-year-old woman with acute myeloid leukaemia developed invasive pulmonary aspergillosis after induction chemotherapy. She was treated with voriconazole at standard dosage. Six days after starting midostaurin, she developed visual hallucinations with a concurrent sharp increase in voriconazole blood concentration (Ctrough 10.3 mg L-1 , target Ctrough 1-5 mg L-1 ). Neurotoxicity was considered to be related to voriconazole overexposure. The concentration of midostaurin was concomitantly six-fold above the average expected level, but without safety issues. Midostaurin was stopped and the dosage of voriconazole was adjusted with therapeutic drug monitoring. The evolution was favourable, with quick resolution and no recurrence of visual hallucinations. To our knowledge, this is the first case suggesting that midostaurin and voriconazole reciprocally inhibit each other's metabolism, leading to increased exposure of both. This case highlights the knowledge gap regarding drug-drug interactions between midostaurin and azole antifungals. Close clinical and therapeutic drug monitoring is advised in such cases.

Novel Therapeutic Approaches to Invasive Candidiasis: Considerations for the Clinician.

Invasive candidiasis (IC), due to the yeast pathogen Candida, is still a major cause of in-hospital morbidity and mortality. The limited number of antifungal drug classes and the emergence of multi-resistant Candida species, such as Candida auris and some Candida glabrata isolates, is concerning. However, recent advances in antifungal drug development provide promising perspectives for the therapeutic approach of IC. Notably, three novel antifungal agents, currently in Phase II/III clinical trials, are expected to have an important place for the treatment of IC in the future. Rezafungin is a novel echinocandin with prolonged half-life. Ibrexafungerp and fosmanogepix are two first-in-class antifungal drugs with broad spectrum activity against Candida spp., including C. auris and echinocandin-resistant species. These novel antifungal agents also represent interesting alternative options because of their acceptable oral bioavailability (ibrexafungerp and fosmanogepix) or their large interdose interval (once weekly intravenous administration for rezafungin) for prolonged and/or outpatient treatment of complicated IC. This review discusses the potential place of these novel antifungal drugs for the treatment of IC considering their pharmacologic properties and their preclinical and clinical data.

What Is New in Pulmonary Mucormycosis?

Mucormycosis is a rare but life-threatening fungal infection due to molds of the order Mucorales. The incidence has been increasing over recent decades. Worldwide, pulmonary mucormycosis (PM) presents in the lungs, which are the third main location for the infection after the rhino-orbito-cerebral (ROC) areas and the skin. The main risk factors for PM include hematological malignancies and solid organ transplantation, whereas ROC infections classically are classically favored by diabetes mellitus. The differences between the ROC and pulmonary locations are possibly explained by the activation of different mammalian receptors-GRP78 in nasal epithelial cells and integrin ß1 in alveolar epithelial cells-in response to Mucorales. Alveolar macrophages and neutrophils play a key role in the host defense against Mucorales. The diagnosis of PM relies on CT scans, cultures, PCR tests, and histology. The reversed halo sign is an early, but very suggestive, sign of PM in neutropenic patients. Recently, the serum PCR test showed a very encouraging performance for the diagnosis and follow-up of mucormycosis. Liposomal amphotericin B is the drug of choice for first-line therapy, together with correction of underlying disease and surgery when feasible. After a stable or partial response, the step-down treatment includes oral isavuconazole or posaconazole delayed release tablets until a complete response is achieved. Secondary prophylaxis should be discussed when there is any risk of relapse, such as the persistence of neutropenia or the prolonged use of high-dose immunosuppressive therapy. Despite these novelties, the mortality rate from PM remains higher than 50%. Therefore, future research must define the place for combination therapy and adjunctive treatments, while the development of new treatments is necessary.