Programmed cell death ligand-1 (PD-L1) expression in desmoid tumors: a retrospective study.

OBJECTIVE: Desmoid tumor is a rare benign but locally aggressive monoclonal and fibroblastic proliferation. It lacks metastatic potential but is associated with a high local recurrence after surgery. It is either characterized by the Beta-catenin gene (CTNNB1) or the adenomatous polyposis coli gene (APC) mutation. The most appropriate treatment approach is watchful waiting with periodic follow-ups for asymptomatic patients. However, symptomatic patients who are not good candidates for surgery due to high morbidity risk may benefit from medical therapy. The new drugs targeting programmed cell death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) display promising results in many cancer types. This study assessed the PD-L1 status of desmoid tumors in 18 patients. PATIENTS AND METHODS: Biopsy and resection materials of 18 patients diagnosed with desmoid tumors between April 2016 and April 2021 were retrieved and assessed for PD-L1 expression. The prepared slides were immunohistochemically stained with PD-L1 antibody using Leica Bond® automated immunohistochemistry stainer. RESULTS: No positive PD-L1 staining of the desmoid tumor cells was detected in any specimens. Intratumoral lymphocytes were present in all specimens. However, five of them were positively stained for PD-L1. CONCLUSIONS: Based on the results of our study, anti-PD-1/PD-L1 therapy may not be a valuable option in desmoid tumor treatment due to the lack of expression of PD-L1 by desmoid tumor cells. Nevertheless, the presence of positively stained intratumoral lymphocytes may warrant further studies.

Chondroid syringoma in an unusual localization: A case report.

Chondroid syringoma (CS) is an uncommon, benign mixed tumor of the skin, composed of mesenchymal and sweat gland elements. In this report, we present a rare case of CS in the middle finger of a 53-year-old male patient. Excisional biopsy and skin grafting were performed. At 2 years of follow-up, the patient had no recurrence. Timely diagnosis and wide excision with a broad margin should be the preferred treatment. Pathologists and clinicians should be aware of the malignant component of CS.

Heterotopic ossification on the volar surface of the distal radius in a child with fibrodysplasia ossificans progressiva: challenges in surgical excision of a rare condition.

Fibrodysplasia ossificans progressiva (FOP) is one of the genetic and developmental forms of heterotopic ossification. We report a case of FOP on the volar surface of the distal radius, located close to the median nerve and radial artery with neurologic symptoms secondary to median nerve entrapment. The patient underwent surgical excision of the heterotopic lesion followed by radiation therapy. He had no signs of recurrence with more than 1 year of follow-up. Careful microsurgical dissection of the heterotopic mass must be performed to prevent the formation of new painful lesions and iatrogenic neurovascular injury. In this syndrome, the possibility of nerve entrapment due to the heterotopic lesion should be considered as the cause of neuropathic pain. Early genetic testing for confirmation of the suspected diagnosis can avoid having to do an unnecessary biopsy.

Resistance emergence among P. aenrginosa in a rat thigh-abscess model. Comparison of imipenem and meropenem treatment.

Resistance emergence to carbapenem antibiotics was studied in a rat-thigh abscess model. Abscesses were developed in three groups with a total of 15 P. aeruginosa strains (three rats per strain). Groups were assigned to imipenem or meropenem treatment while one was left antibiotic-free. Test strains were fully susceptible to these antibiotics and the "Mutant Preventing Concentrations" of imipenem and meropenem over these strains were comparable. Antibiotic serum levels, assessed by serum bioassay test, were similar among therats. After four days, rats (n=45) were sacrificed and carbapenem resistant mutants were selected on imipenem (4 mg/L) and meropenem (4 mg/L) supplemented agar plates. Resistant variants of three strains, from four abscesses, were detected; one in the meropenem group, two in the imipenem and one in the untreated group. The MICs of imipenem and meropenem for the mutants were increased fourfold times or even higher of their counterparts. Resistance emergence under antibiotic pressure in P. aeruginosa has been shown in various conditions. To our knowledge, however, resistance emergence in abscess and also the comparison of imipenem and meropenem in this regard has not been studied before.

Risk of nosocomial infections and effects of total cholesterol, HDL cholesterol in surgical patients.

BACKGROUND AND AIMS: Changes of lipoprotein pattern in plasma occur in many acute infections. The aim of this study was to analyse the role of total cholesterol and HDL cholesterol in postsurgical patients with nosocomial infection. METHODS: Four hundred and eighteen patients admitted to our department and operated on for various diseases are included in this prospective study. Various conventional risk factors for nosocomial infections were recorded. Biochemical parameters with plasma total cholesterol and HDL-cholesterol (HDL-C) levels were measured. RESULTS: In our study, the most frequent infection was surgical site infection. There was an increased association between low HDL-C level and nosocomial infections such as surgical site and pulmonary infections. HDL levels may be used as predictive parameter for surgical nosocomial infections. CONCLUSIONS: HDL-C levels seem to be one of the risk factors for postoperative nosocomial infection. Although total cholesterol level was not significantly increased, it may be also associated with the infection risk. Screening of lipoprotein pattern in patients undergoing operation may be useful for ascertaining of risk for nosocomial infection.

Piperacillin with and without tazobactam against extended-spectrum beta-lactamase-producing Pseudomonas aeruginosa in a rat thigh abscess model.

BACKGROUND: We compared the antibacterial effect of piperacillin, piperacillin-tazobactam and imipenem in a paired rat thigh abscess model. METHODS: Two abscesses were provoked in the thighs of rats, one on the right with an extended-spectrum beta-lactamase (OXA-14)-producing Pseudomonas aeruginosa (Ps-162) and the other on the left thigh with a control strain. RESULTS: The colony counts from the abscesses in log 10 colony-forming units per gram (mean +/- SD) in the imipenem group were 2.78 +/- 1.71 and 3.19 +/- 1.66, in the piperacillin-tazobactam group 4.36 +/- 0.23 and 2.44 +/- 1.97, and in the piperacillin group 4.44 +/- 0.21 and 3.71 +/- 0.99 for Ps-162 and the control strain, respectively. The mean colony counts were significantly different (p < 0.05) between Ps-162 and the control strain in the piperacillin and piperacillin-tazobactam groups. CONCLUSION: These data showed that piperacillin and piperacillin-tazobactam were significantly less effective against extended-spectrum beta-lactamase-producing P. aeruginosa, while imipenem was equally effective against both Ps-162 and the control strain in this abscess model.