Musculoskeletal involvement in neglected tropical diseases: a comprehensive review.

Neglected tropical diseases (NTDs) encompass a group of diseases predominantly found in tropical regions, with origins dating back to their inclusion in the United Nations Millennium Development Goals in 2000. This initiative aimed to raise awareness and global funding to combat these diseases, which thrive in areas with limited sanitation, healthcare, and education. NTDs are caused by various pathogens such as bacteria, fungi, parasites, and viruses and affect over two billion individuals in resource-poor communities, leading to preventable deaths and devastating consequences. While the musculoskeletal system is only occasionally affected, the resulting chronic disabilities prevent individuals from working, posing a significant socioeconomic burden in this region of the world. Some NTDs exhibit distinct imaging features, and radiologists need to be aware of these characteristics to facilitate early treatment. In this review, we delve into musculoskeletal NTDs, focusing on clinical features and imaging findings, differential diagnosis, and clinical management.

Upper extremity infection: imaging features with focus on magnetic resonance imaging.

Upper extremity infections are frequently seen, especially in individuals with weakened immune system, posttraumatic events, and after surgery procedures. If not properly treated, such conditions can lead to serious consequences, such as movement impairment, amputation, and even mortality. These infections have the potential to spread extensively from their initial site of entry, traversing interconnected spaces either intra or extra-compartmental. Understanding the relevant anatomy is crucial to assess location and stage of infection, since surgical intervention and intravenous antibiotics are usually required. In this article, the authors provide a comprehensive review of the imaging findings of upper extremity infection, focusing on magnetic resonance imaging (MRI). Furthermore, this article sheds light on the pivotal role of radiology in managing hand, elbow, and shoulder infections offering an overview of available treatment options. KEY FINDINGS: Various types of infections affecting the upper extremity will be discussed, including infectious tenosynovitis, deep space infections, septic arthritis, and osteomyelitis. Authors also highlight anatomical spaces, common pathogens, spread routes, and key radiological features of these conditions.

Outcomes of imaging-guided corticosteroid injections in hip and knee osteoarthritis patients: a systematic review.

PURPOSE: The purpose of this systematic review is to evaluate the current literature on the use of image-guided corticosteroid injections in the treatment of patients with knee and hip OA. EVIDENCE ACQUISITION: We conducted a comprehensive literature search through June 30, 2022. Publication type, study design, imaging guidance modality, osteoarthritis severity, number of injections, steroid type and dose, anesthetic type and dose, the total number of patients, follow-up intervals, and measured outcomes were extracted from the included studies. EVIDENCE SYNTHESIS: There were 23 included studies (10 hips, 12 knees, 1 both hip and knee). Hip injections were found to be effective in treating short- and long-term pain and more effective than hyaluronic acid, Mepivacaine, NSAIDs, and normal saline in terms of improvement in pain and/or function. There was less impact on QoL. Knee injections were found either to have little or no impact or were similar or inferior to comparison injections (intra-articular hyaluronic acid, PRP, NSAIDs, normal saline, adductor canal blocks). Study data could not be aggregated because the corticosteroid types and doses, methods of outcome assessment, and follow-up time points varied widely. CONCLUSION: Our systematic review found generally positive outcomes for the hip, but overall negative outcomes for the knee, although hip injections may carry a risk of serious adverse outcomes. A larger trial with uniform methodology is warranted. Specific studies on the adverse effects of corticosteroid injections are also warranted.

MRI findings of closed hand injuries in adolescent goalkeepers: a case-based review.

Soccer-related injuries in youth goalkeepers are underrepresented in epidemiological studies, despite goalkeepers experiencing distinct types of upper limb injuries and training loads compared to outfield players. Digit injuries are particularly prevalent, with up to five times more upper extremity injuries reported in this position. Such injuries can lead to interphalangeal joint instability and an increased risk of reinjury. Mechanisms of injury include falls, axial loading of digits, and rotational force due to grasping activities. The proximal interphalangeal joint is the most frequently injured in sports, followed by the metacarpophalangeal joint of the thumb. Achieving precise diagnosis can be challenging due to the complex soft-tissue anatomy of the hand. Radiologists play a crucial role in accurate diagnosis through imaging studies, enabling timely treatment. This article focuses on closed traumatic finger and thumb injuries in adolescent goalkeepers, describing injury mechanisms and outlining relevant MRI features to facilitate proper clinical approaches for diagnosis based on imaging findings.

Postoperative Imaging of the Rotator Cuff: A Systematic Review and Meta-Analysis.

BACKGROUND. It is unclear which, MRI or ultrasound (US), is the most useful imaging tool to diagnose rotator cuff retears. OBJECTIVE. The objective of this study was to evaluate MRI and US in terms of diagnosing retear of a repaired rotator cuff tendon using a systematic review and meta-analysis. EVIDENCE ACQUISITION. A comprehensive literature search was performed on the main concepts of MRI (including noncontrast MRI and MR arthrography), US, and rotator cuff repairs. Inclusion criteria consisted of original research studies that assessed the diagnostic accuracy of MRI and US (index tests) for the diagnosis of rotator cuff tendon retear after prior rotator cuff repair using surgical findings as the reference standard. QUADAS-2 was used to assess methodologic quality. Meta-analyses were performed to compare MRI and US studies in the diagnosis of all retears and of full-thickness retears. Study variation was analyzed using the Cochran Q test and I2 statistic. EVIDENCE SYNTHESIS. Eight studies (MRI, n = 6; US, n = 2) satisfied inclusion and exclusion criteria, consisting of 304 total patients (MRI, n = 221; US, n = 83) and 309 shoulders (MRI, n = 226; US, n = 83). Years of publication ranged from 1993 to 2006 for the MRI studies and from 2003 to 2018 for the US studies. Two studies had high risk of bias in terms of applicability to clinical practice because of patient selection. Five studies had potential risk of bias in two categories, whereas two had potential risk of bias in three categories. For all retears, mean sensitivity and specificity for MRI were 81.4% (95% CI, 73.3-87.5%) and 82.6% (95% CI, 76.3-87.5%) and 83.7% (95% CI, 67.4-92.7%) and 90.7% (95% CI, 73.6-97.1%) for US. For full-thickness retears, mean sensitivity and specificity for MRI were 85.9% (95% CI, 80.2-90.2%) and 89.1% (95% CI, 84.6-92.4%) and 89.7% (95% CI, 75.6-96.1%) and 91.0% (95% CI, 75.5-97.1%) for US. There was no significant difference in terms of sensitivity or specificity for either comparison (p = .28-.76). CONCLUSION. Our analyses revealed no significant difference between US and MRI for the diagnosis of rotator cuff tendon tears after prior cuff repair. CLINICAL IMPACT. Either MRI or US can be considered a first-line imaging option to assess suspected rotator cuff retear after prior repair.

Cell wall thickenings and tylosoid: developmental morphology reveals novelties for secretory canals in Protium ovatum (Burseraceae).

We investigated the structure, histochemistry, and ultrastructure of the secretory canals in the vegetative axis of Protium ovatum from a developmental perspective. Samples of roots, stems, and leaves were analyzed using light and transmission electron microscopy. Secretory canals composed of a uniseriate epithelium and a wide lumen occurred in the phloem of all analyzed organs. Schizogenesis and lysigenesis were merging processes involved in the origin, growth, ramification, and fusion of the secretory canals, forming an anastomosed secretory net. Essential oils, polysaccharides, and proteins were detected in the epithelial cells, as well as plastids with poorly developed thylakoids, dictyosomes, rough endoplasmic reticulum, polysomes, and oil drops, showing the mixed nature of the secretion. Epithelial cells exhibited pectin-cellulosic thickenings in the anticlinal and radial walls. These thickenings may act in directing the secretion flux toward the lumen, protecting the neighboring tissues from the toxicity of secreted metabolites. Structural irregularities observed in the mitochondria cristae in epithelial cells may be associated with processes induced by toxic substances. Epithelial cells protruded into the lumen and became lignified in the outer portion of the secondary phloem, obliterating the non-functional secretory canals. We propose that this phenomenon presents a physiological significance similar to that of tylose, preserving the secretion flow inside the active portions of the secretory system. To our knowledge, epithelial cells with wall thickenings, mitochondria with structural abnormalities, and obliteration of non-functional canals are features reported for the first time for Burseraceae. These features have important functional significance for Burseraceae secretory system and contribute to a deeper knowledge of P. ovatum, a medically and economically important plant.

Bilateral pectoralis major MRI in weightlifters: findings of the non-injured side versus age-matched asymptomatic athletes.

OBJECTIVE: To evaluate magnetic resonance imaging (MRI) features of the contralateral side in weightlifting athletes with pectoralis major (PM) tears. We hypothesized that MRI of the non-injured side may present increased pectoralis major tendon (PMT) length and thickness and greater pectoralis major muscle (PMM) volume and cross-sectional area when compared with the control group. METHODS: We retrospectively identified MRI cases with unilateral PM injury and reviewed imaging findings of the contralateral side. Also, we evaluated MRI from ten asymptomatic control weightlifting athletes, with PM imaging from both sides. Two musculoskeletal radiologists independently reviewed MRI and measured PMT length, PMT thickness, PMM volume (PMM-vol) and PMM cross-sectional area (PMM-CSA), as well as humeral shaft cross-sectional area (Hum-CSA) and the ratio between PMM-CSA and Hum-CSA (PMM-CSA/Hum-CSA). Data were compared between the non-injured side and controls. The MRI protocol from both groups was the same and included T1 FSE and T2 FATSAT axial, coronal, and sagittal images, one side at a time. RESULTS: We identified 36 male subjects with unilateral PM injury with mean age 35.7 ± 8 years and 10 age- and gender-matched controls (p = 0.45). A total of 36 PM MRI with non-injured PM and 20 PM MRI studies were included in this study. PMT length and PMT thickness were significantly higher in contralateral PM injury versus control subjects (both P < 0.001). Also, PM-CSA and Hum-CSA were greater in the contralateral PM injury group (P = 0.032 and P < 0.001, respectively). PMT thickness > 2.95 mm had 80.6% sensitivity and 90.0% specificity to differentiate the non-injured PM group from controls. CONCLUSION: Non-injured side MR imaging of patients with previous contralateral PM lesion demonstrates greater PMT thickness and length as well as PM-CSA and Hum-CSA than controls.

Roles of Calcium Signaling in Gene Expression and Photosynthetic Acclimatization of Solanum lycopersicum Micro-Tom (MT) after Mechanical Damage.

A momentary increase in cytoplasmic Ca2+ generates an oscillation responsible for the activation of proteins, such as calmodulin and kinases, which interact with reactive oxygen species (ROS) for the transmission of a stress signal. This study investigated the influence of variations in calcium concentrations on plant defense signaling and photosynthetic acclimatization after mechanical damage. Solanum lycopersicum Micro-Tom was grown with 0, 2 and 4 mM Ca2+, with and without mechanical damage. The expression of stress genes was evaluated, along with levels of antioxidant enzymes, hydrogen peroxide, lipid peroxidation, histochemistry, photosynthesis and dry mass of organs. The ROS production generated by mechanical damage was further enhanced by calcium-free conditions due to the inactivation of the oxygen evolution complex, contributing to an increase in reactive species. The results indicated that ROS affected mechanical damage signaling because calcium-free plants exhibited high levels of H2O2 and enhanced expression of kinase and RBOH1 genes, necessary conditions for an efficient response to stress. We conclude that the plants without calcium supply recognized mechanical damage but did not survive. The highest expression of the RBOH1 gene and the accumulation of H2O2 in these plants signaled cell death. Plants grown in the presence of calcium showed higher expression of SlCaM2 and control of H2O2 concentration, thus overcoming the stress caused by mechanical damage, with photosynthetic acclimatization and without damage to dry mass production.

Apoplasmic barrier in the extrafloral nectary of Citharexylum myrianthum (Verbenaceae).

MAIN CONCLUSION: The cytological changes underlying the formation of an apoplasmic barrier in the multi-layered extrafloral nectaries of Citharexylum myrianthum are compatible with the synthesis, transport and deposition of suberin. In terms of ontogenesis and function, the intermediate layers of these nectaries are homologous with the stalks of nectar-secreting trichomes. Anticlinal cell wall impregnations are common in trichomatic nectaries and their functions as endodermis-like barriers have been discussed because of possible direct effects on the nectary physiology, mainly in the nectar secretion and resorption. However, the cytological events linked to nectary wall impregnations remain little explored. This study documents the ontogenesis and the fine structure of the EFN cells, and cytological events linked to the wall impregnations of multi-layered extrafloral nectaries (EFNs) in Citharexylum myrianthum Cham. (Verbenaceae). EFNs are patelliform, and differentiated into (a) a multicellular foot, which is compound in structure and vascularised with phloem strands, (b) a bi-layered intermediate region with thickened cell walls and (c) a single-layered secretory region with palisade-like cells. EFNs are protodermal in origin, starting with a single protodermal cell and ending with the complex, multi-layered structure. The cell wall impregnations first appear in the very young EFN and increase towards maturity. Lipid patches (assumed to be suberin) are deposited on the inner faces of the primary walls, first along the anticlinal walls and then extend to the periclinal walls. On both walls, plasmodesmata remain apparently intact during the maturation of the EFNs. In the peripheral cytoplasm there are abundant polymorphic plastids, well-developed Golgi bodies often close to rough endoplasmic reticulum profiles, mitochondria and polyribosomes. Cytological events linked to the wall impregnations are consistent with suberin synthesis, transport and deposition. Our findings offer new insights into the structure-properties of specialised nectary cell walls and so should contribute to our knowledge of the physiological and protective roles of this structure in nectar glands.

Subacromial-subdeltoid bursitis following COVID-19 vaccination: a case of shoulder injury related to vaccine administration (SIRVA).

Vaccination injection site adverse reactions are usually mild and transient, and post-vaccination musculoskeletal symptoms, such as myalgia and arthralgia, are very common. Shoulder injury related to vaccine administration (SIRVA), defined as shoulder pain and limited range of motion occurring after the administration of a vaccine intended for intramuscular administration in the upper arm, is a well-established condition in the medical literature, yet underreported. In such cases, subacromial-subdeltoid bursitis may occur, leading to shoulder dysfunction and ongoing pain. Millions of doses of vaccines for the prevention of COVID-19 have been administered to adults worldwide during the pandemic. We report a case of subacromial-subdeltoid bursitis after COVID-19 vaccination, related to the unintentional injection of vaccine solution into the bursa resulting in a robust immune-mediated inflammatory reaction.

Comparison between radiography and magnetic resonance imaging for the detection of sacroiliitis in the initial diagnosis of axial spondyloarthritis: a cost-effectiveness study.

OBJECTIVE: The purpose of our study was to determine the cost-effectiveness of radiography and MRI-based imaging strategies for the initial diagnosis of sacroiliitis in a hypothetical population with suspected axial spondyloarthritis. MATERIALS AND METHODS: A decision analytic model from the health care system perspective for patients with inflammatory back pain suggestive of axial spondyloarthritis was used to evaluate the incremental cost-effectiveness of 3 imaging strategies for the sacroiliac joints over a 3-year horizon: radiography, MRI, and radiography followed by MRI. Comprehensive literature search and expert opinion provided input data on cost, probability, and utility estimates. The primary effectiveness outcome was quality-adjusted life-years (QALYs), with a willingness-to-pay threshold set to $100,000/QALY gained (2018 American dollars). RESULTS: Radiography was the least costly strategy ($46,220). Radiography followed by MRI was the most effective strategy over a 3-year course (2.64 QALYs). Radiography was the most cost-effective strategy. MRI-based and radiography followed by MRI-based strategies were not found to be cost-effective imaging options for this patient population. Radiography remained the most cost-effective strategy over all willingness-to-pay thresholds up to $100,000. CONCLUSION: Radiography is the most cost-effective imaging strategy for the initial diagnosis of sacroiliitis in patients with inflammatory back pain suspicious for axial spondyloarthritis.

Autophagy and vacuolar biogenesis during the nectary development.

MAIN CONCLUSION: Different autophagy pathways are a driver of vacuolar biogenesis and are development stage specific during the extrafloral nectary development in Citharexylum myrianthum. Plant autophagy plays an important role in various developmental processes such as seed germination, pollen maturation and leaf senescence. However, studies that address the evidence of autophagy and its role in the development of plant glands are scarce and largely restricted to laticifers. Regarding nectary, studies have repeatedly pointed to signs of degradation associated with the end of the secretory cycle, without exploring autophagy. Likewise, the relationship between autophagy and biogenesis of vacuoles remains an unexplored issue. In this study, using conventional and microwave fixation in association with ultracytochemical methods for transmission electron microscopy, we investigated the occurrence of autophagy and its implication in the differentiation of extrafloral nectary in Citharexylum myrianthum (Verbenaceae) under natural conditions, focusing on the vacuole biogenesis. We described a variety of vacuole types associated with the stage of nectary epidermis development, which differs with respect to origin, function and nature of the products to be stored. Three distinct autophagy pathways were detected: macroautophagy, microautophagy (both restricted to the undifferentiated epidermal cells, at the presecretory stage) and megaautophagy (circumscribed to the differentiated epidermal cells, at the postsecretory stage). Our study clearly demonstrated that the vacuole variety and autophagy processes in the nectary epidermal cells are development specific. This study highlights the role of autophagy in vacuole biogenesis and its implications for the development of nectary and opens new venues for future studies on regulation mechanisms for autophagy in plant secretory structures under normal conditions.

Artificial Intelligence in Musculoskeletal Imaging: Current Status and Future Directions.

OBJECTIVE. The objective of this article is to show how artificial intelligence (AI) has impacted different components of the imaging value chain thus far as well as to describe its potential future uses. CONCLUSION. The use of AI has the potential to greatly enhance every component of the imaging value chain. From assessing the appropriateness of imaging orders to helping predict patients at risk for fracture, AI can increase the value that musculoskeletal imagers provide to their patients and to referring clinicians by improving image quality, patient centricity, imaging efficiency, and diagnostic accuracy.

Structural associations between organelle membranes in nectary parenchyma cells.

MAIN CONCLUSION: The close association between membranes and organelles, and the intense chloroplast remodeling in parenchyma cells of extrafloral nectaries occurred only at the secretion time and suggest a relationship with the nectar secretion. Associations between membranes and organelles have been well documented in different tissues and cells of plants, but poorly explored in secretory cells. Here, we described the close physical juxtaposition between membranes and organelles, mainly with chloroplasts, in parenchyma cells of Citharexylum myrianthum (Verbenaeceae) extrafloral nectaries under transmission electron microscopy, using conventional and microwave fixation. At the time of nectar secretion, nectary parenchyma cells exhibit a multitude of different organelle and membrane associations as mitochondria-mitochondria, mitochondria-endoplasmic reticulum, mitochondria-chloroplast, chloroplast-nuclear envelope, mitochondria-nuclear envelope, chloroplast-plasmalemma, chloroplast-chloroplast, chloroplast-tonoplast, chloroplast-peroxisome, and mitochondria-peroxisome. These associations were visualized as amorphous electron-dense material, a network of dense fibrillar material and/or dense bridges. Chloroplasts exhibited protrusions variable in shape and extension, which bring them closer to each other and to plasmalemma, tonoplast, and nuclear envelope. Parenchyma cells in the pre- and post-secretory stages did not exhibit any association or juxtaposition of membranes and organelles, and chloroplast protrusions were absent. Chloroplasts had peripheral reticulum that was more developed in the secretory stage. We propose that such subcellular phenomena during the time of nectar secretion optimize the movement of signaling molecules and the exchange of metabolites. Our results open new avenues on the potential mechanisms of organelle contact in parenchyma nectary cells, and reveal new attributes of the secretory cells on the subcellular level.

Fusoid cells in the grass family Poaceae (Poales): a developmental study reveals homologies and suggests new insights into their functional role in young leaves.

Background and Aims: In mature grass leaf blades as seen in cross-section, oblong cell-like structures have been interpreted most recently as intercellular gas spaces delimited by successive collapsed fusoid cells. These cells have been reported in at least seven of 12 subfamilies of Poaceae and are considered a synapomorphy for the family; however, no developmental work has been performed to verify their meristematic origin or to assess possible homologies within the graminid clade (= Flagellariaceae + [(Joinvilleaceae + Ecdeiocoleaceae) + Poaceae]) or among subfamilies of Poaceae. A developmental study was therefore carried out, including 20 species in three families (Flagellariaceae, Joinvilleaceae and Poaceae), representing the earlier-diverging and derived branches within the graminid clade and Poaceae. Methods: Light microscopy was combined with scanning electron microscopy, cryoscanning electron microscopy and transmission electron microscopy to study the development of leaves taken from the shoot apex of young plants. Mature leaf blades also were taken from living or dried plants and the mid-portion was studied. Key Results: Developmental results show that, in mature leaf blades as seen in cross-section, one apparent fusoid cell is typically a cavity resulting from the collapse of the initial fusoid cell and its internal divisions, which are herein interpreted as derivative cells with formation of cell plates only. Each cavity is delimited by successive collapsed fusoid cells arranged perpendicularly to the veins. Fusoid cells in all studied Poaceae members originate from the ground meristem, as do the colourless cells in Joinvillea ascendens (Joinvilleaceae). These two types of mesophyll cell have a strongly similar ontogeny, distinguished mainly by the collapse of the fusoid cells in Poaceae, which is not observed in the colourless cells in J. ascendens. Conclusions: Within the Poaceae, the meristematic origin of fusoid cells is the same in the early-diverging lineages, BOP clade and Panicoideae, and thus they are homologous within the family. The same topography and meristematic origin suggest that fusoid cells in Poaceae and colourless cells in Joinvilleaceae are homologous. The results also suggest that the role played by the fusoid cells in young grass leaves is related to synthesis and storage of starch granules at early stages of development.

Role of rare germline copy number variation in melanoma-prone patients.

AIM: This work evaluates a possible causative role for germline copy number variants (CNVs) in melanoma predisposition. PATIENTS & METHODS: A total of 41 melanoma-prone Brazilian patients were investigated for CNVs using 850K single nucleotide polymorphism arrays. RESULTS: Ten rare CNVs were identified in nine patients, comprising 54 known genes, mostly related to cancer. In silico analyses revealed gene enrichment for cellular development and growth, and proliferation, highlighting five genes directly associated with the melanoma phenotype (ANGPT1, IDH1, PDE5A, HIST1H1B and GCNT2). CONCLUSION: Patients harboring rare CNVs exhibited a decreased age of disease onset, in addition to an overall higher skin cancer predisposition. Our findings suggest that rare CNVs contribute to melanoma susceptibility, and should be taken into account when investigating cancer risk factors.

Lymphovascular invasion and histologic grade are associated with specific genomic profiles in invasive carcinomas of the breast.

Lymphovascular invasion (LVI) and histologic grade are clinical parameters of high prognostic value in breast cancer and indicate the level of tumor aggressiveness. Many studies have focused on the association of breast cancer subtypes with gene expression and chromosomal profiles, but considerably less genomic information is available regarding traditional prognostic factors such as histologic grade and LVI. We studied by array-CGH a group of 57 invasive ductal carcinomas of the breast to outline the DNA copy number aberration (CNA) profile linked to high histologic grades and LVI. Selected CNAs were validated using real-time quantitative PCR (qPCR). Furthermore, gene expression analysis was performed in a subset of 32 of these tumors, and findings were integrated with array-CGH data. Our findings indicated an accumulation of genomic alterations in high-grade breast tumors compared to low-grade samples. Grade III tumors showed higher number of CNAs and larger aberrations than low-grade tumors and displayed a wide range of chromosomal aberrations, which were mainly 5p, 8q, 10p, 17q12, and 19 gains, and 3p, 4, 5q proximal, 9p, 11p, 18q, and 21 losses. The presence of LVI, a well-established prognostic marker, was not significantly associated with increased genomic instability in comparison to breast tumors negative for LVI, considering the total number of chromosomal alterations. However, a slightly increase in the frequency of specific alterations could be detected in LVI-positive group, such as gains at 5p, 16p, 17q12, and 19, and losses at 8p, 11q, 18q, and 21. Three newly reported small-scale rearrangements were detected in high-risk tumors (LVI-positive grade III) harboring putative breast cancer genes (amplicons at 4q13.3 and 11p11.2, and a deletion at 12p12.3). Furthermore, gene expression analysis uncovered networks highlighting S100A8, MMP1, and MED1 as promising candidate genes involved in high-grade and LVI-positive tumors. In summary, a group of genomic regions could be associated with high-risk tumors, and expression analysis pinpointed candidate genes deserving further investigation. The data has shed some light on the molecular players involved in two highly relevant prognostic factors and may further add to the understanding of the mechanisms of breast cancer aggressiveness.

Glandular trichome density and essential oil composition in leaves and inflorescences of Lippia origanoides Kunth (Verbenaceae) in the Brazilian Cerrado.

The essential oils from leaves and inflorescences of Lippia origanoides Kunth present aromatic and medicinal potential and have been used to treat several diseases, including melanoma. In Brazil, L. origanoides is commonly found in campo cerrado and cerrado stricto sensu, physiognomies featured mainly by the differential light conditions to which short and medium-sized plants are subjected. Our aim was to investigate the glandular trichome density and the yield and chemical composition of the essential oils in leaves and inflorescences of L. origanoides from campo cerrado and cerrado stricto sensu. For glandular density analysis, leaves and inflorescences were processed according to conventional techniques for scanning electron microscopy. The essential oils of leaves and inflorescences were obtained by hydrodistillation and identified with gas chromatography. Bracts and sepals showed the highest glandular density, followed by petals and leaves. The glandular density in the abaxial leaf surface was higher in individuals from the campo cerrado. In both populations the essential oil yield was higher in inflorescences than in leaves. The chemical composition of the essential oils varied among individuals from different areas and inside a same population. Our results demonstrated the chemical plasticity of L. origanoides suggesting the importance of monitoring its popular use.