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Low-grade myofibroblastic sarcoma (LGMS) represents an atypical tumor composed of myofibroblasts with a variety of histological patterns and with a high tendency to local recurrence and a low probability of distant metastases. LGMS has predilection for the head and neck regions, especially the oral cavity. This study aimed to report 13 new cases of LGMS arising in the oral and maxillofacial region. This study included LGMS cases from five oral and maxillofacial pathology laboratories in four different countries (Brazil, Peru, Guatemala, and South Africa). Their clinical, radiographic, histopathological, and immunohistochemical findings were evaluated. In this current international case series, most patients were females with a mean age of 38.7 years, and commonly presenting a nodular lesion in maxilla. Microscopically, all cases showed a neoplasm formed by oval to spindle cells in a fibrous stroma with myxoid and dense areas, some atypical mitoses, and prominent nucleoli. The immunohistochemical panel showed positivity for smooth muscle actin (12 of 13 cases), HHF35 (2 of 4 cases), β-catenin (3 of 5 cases), desmin (3 of 11 cases), and Ki-67 (range from 5 to 50%). H-caldesmon was negative for all cases. The diagnosis of LGMS was confirmed in all cases. LGMS shows predominance in young adults, with a slight predilection for the female sex, and maxillary region. LGMS should be a differential diagnosis of myofibroblastic lesions that show a proliferation of spindle cells in a fibrous stroma with myxoid and dense areas and some atypical mitoses, supporting the diagnosis with a complementary immunohistochemical study. Complete surgical excision with clear margins is the treatment of choice. However, long-term follow-up information is required before definitive conclusions can be drawn regarding the incidence of recurrence and the possibility of metastasis., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Objectives: New anti-mycobacterial entities with novel mechanisms of action are clinically needed for treating resistant forms of tuberculosis. The purpose of this study was to evaluate anti-tubercular activity and selectivity of seven recently isolated natural products from Colombian plants., Methods: MICs were determined using a liquid medium growth inhibition assay for Mycobacterium tuberculosis H(37)Rv and both solid and liquid media growth inhibition assays for Mycobacterium bovis BCG. Escherichia coli growth inhibition and mammalian macrophage cell toxicity were evaluated to establish the degree of selectivity of the natural product against whole cell organisms. Enzymatic inhibition of ATP-dependent MurE ligase from M. tuberculosis was assayed using a colorimetric phosphate detection method. The most active compound, 3-methoxynordomesticine hydrochloride, was further investigated on M. bovis BCG for its inhibition of sigmoidal growth, acid-fast staining and viability counting analysis., Results: Aporphine alkaloids were found to be potent inhibitors of slow-growing mycobacterial pathogens showing favourable selectivity and cytotoxicity. In terms of their endogenous action, the aporphine alkaloids were found inhibitory to M. tuberculosis ATP-dependent MurE ligase at micromolar concentrations. A significantly low MIC was detected for 3-methoxynordomesticine hydrochloride against both M. bovis BCG and M. tuberculosis H(37)Rv., Conclusions: Considering all the data, 3-methoxynordomesticine hydrochloride was found to be a potent anti-tubercular compound with a favourable specificity profile. The alkaloid showed MurE inhibition and is considered an initial hit for exploring related chemical space.

Background: This study describes the histopathological, immunohistochemical (IHC) and in situ hybridization (ISH) data of 25 cases of oral ulcers in HIV-positive patients, with clinical and microscopical features similar to ulcers not otherwise specified (NOS)/necrotizing ulcerative stomatitis (NUS)., Methods: Sex, age and clinical history were obtained from the clinical records. Histological analysis for H&E, Gomori-Grocott and Ziehl-Neelsen stains, IHC analysis to detect infectious agents and to characterize inflammatory cellular infiltrate, and ISH for cytomegalovirus (CMV) and EBER1/2 were performed., Results: Twenty-one patients were men and four were women (mean age of 34.6 years). The tongue was preferentially affected. Microscopically, the lesions showed extensive necrosis, leukocytoclasia, vasculitis with luminal fibrin clots and an intense inflammatory cellular infiltrate predominated by CD68(+) atypical large cells, normal-sized and crescent-shaped nuclei macrophages, interspersed by CD8(+) T lymphocytes. Mast cells were also observed in all samples studied. CD4(+) T lymphocytes, CD20(+) B lymphocytes and VS38c(+) plasma cells were practically absent. CMV and EBER1/2 were identified in scarce cells of 3 and 16 of 25 cases respectively., Conclusion: These results show that CD68(+) macrophages, followed by CD8(+) T lymphocytes, were the predominant inflammatory cells, indicating they are relevant to the pathogenesis of the ulcers, possibly reflecting an abnormal immune response in the oral mucosa. The clinicopathological and immunoprofile features of the present cases are similar to NOS ulcers/NUS in HIV-positive patients.

Background: Adenomatoid odontogenic tumour (AOT) is a benign odontogenic jaw lesion. The aim of this study was to update the biological profile of AOT., Material and Methods: Cases published in the literature and cases in files of co-authors were included., Results: 550 new cases were retrieved, and of a total of 1082 cases analysed, 87.2% were found in the second and third decades. The M:F ratio was 1:1.9. 70.8% were of the follicular variant (extrafollicular: 26.9%, peripheral: 2.3%). 64.3% occurred in the maxilla. 60% of follicular AOTs were associated with unerupted canines. Nineteen cases of AOT (2.8%, M:F ratio was 1:1.4) were associated with embedded third molars. Twenty-two peripheral AOTs (2.3%, M:F ratio was 1:5.3) were recorded. The relative frequency (RF) of AOT ranged between 0.6% and 38.5%, revealing a considerably wider AOT/RF range than hitherto reported (2.2-7.1%)., Conclusions: This updated review based on the largest number of AOT cases ever presented, confirms the distinctive, although not pathognomonic clinicopathological profile of the AOT, its worldwide occurrence, and its consistently benign behaviour.

Abnormal proteinaceous deposits identified by light microscopy as amyloid in labial salivary gland biopsies were studied by transmission electron microscopy in order to establish their ultrastructural characteristics. Results showed fine fibrils approximately 10 nm in diameter located in close relation to the basal lamina of the secretory end-pieces and ducts as well as in the interstitial connective tissue stroma of labial salivary glands; these are the typical features of amyloid. Thus, the present study confirms the light microscopy diagnosis of amyloid deposits in labial salivary gland biopsies, supporting the use of lip biopsy as a readily accessible method for the diagnosis of secondary amyloidosis.

Both labial salivary gland and gingival biopsies were taken from 19 patients with clinical findings suggestive of secondary amyloidosis. Amyloid deposits were present in all salivary gland biopsies (19/19) while amyloid deposits in gingiva were observed only in three cases (16%). No amyloid was found in similar biopsies from 11 control patients. Periductal amyloid involvement was found along the basement membrane in all salivary gland samples; additionally, 16 cases had periacinar infiltration (84%), 13 had perivascular (68%) and 7 (37%) showed interstitial deposits. Amyloid in gingiva was seen along the epithelial basement membrane, as in salivary glands, although in isolated areas and scattered at the top of some dermal papillae and small blood vessels. In secondary amyloidosis it therefore appears that amyloid is deposited along the epithelial basement membrane before perivascular deposition occurs. This study presents a new highly sensitive and reliable method for the diagnosis of secondary amyloidosis, a method which is technically simple, free from complications and well-accepted by the patients.