OBJECTIVE: To investigate whether the inhibition of 12/15-lipoxygenase (12/15-LOX), one of the core enzymes of the arachidonic acid cascade, suppresses orthodontically induced root resorption (OIRR), and examine the involvement of the hyaline degeneration of periodontal ligament cells and odontoclast differentiation.
METHODS: The left maxillary first molars of 10-week-old male Wistar rats were moved mesially for 14 days using a closed-coil spring (25 cN) inserted between the first molar and incisor. The rats were intraperitoneally administered with a 12/15-LOX specific inhibitor (ML-351; 0.05 mmol/kg) daily in the experimental group or vehicle (dimethyl sulfoxide) in the control group. Tooth movement was measured using microcomputed tomography on day 14. The appearance of OIRR, hyaline degeneration, osteoclasts, and odontoclasts was evaluated via histological analysis. Immunohistochemical staining for receptor-activated NF-kB ligand (RANKL) and osteoprotegerin was performed.
RESULTS: OIRR observed on day 14 in the control group was strongly suppressed by ML-351 treatment. Hyaline degeneration observed on the compression side on day 3 and the appearance of osteoclasts and odontoclasts on days 3 and 14 were significantly suppressed by ML-351. RANKL expression on day 3 was significantly suppressed by ML-351. These key processes in OIRR were substantially suppressed by ML-351 treatment.
CONCLUSIONS: Inhibition of 12/15-LOX reduced OIRR by suppressing hyaline degeneration and subsequent odontoclast differentiation.

Introduction Uterine masses are commonly submitted for frozen section, to guide the surgeon, regarding the type and extent of the procedure during surgery. Despite the technical difficulties in processing, sectioning, and staining of frozen section samples, it remains a fairly reliable intraoperative tool. Aim This study aims to analyze the diverse spectrum of uterine masses sent for frozen sections for two years. In addition, it aims to analyze the histomorphology of the uterine masses sent for the frozen section and correlate it with that of the routine histopathological findings, thereby justifying the diagnostic value of the frozen section with this study. Furthermore, the study aims to classify the lesions into benign and malignant, quantify their frequency, and list the most common lesions seen in the uterine mass specimens sent for frozen section analysis. Methodology This retrospective descriptive study includes data from January 2021 to December 2022, retrieved from the archives of the Department of Pathology at Saveetha Medical College. This study includes a total of 76 cases, including all the uterine masses sent for frozen section analysis during the study period. Results Of the total of 76 cases received, 17 (22.4%) were malignant and 59 (77.6%) were benign. Of the malignant cases reported, the most common was endometrial carcinoma, and the least common entities encountered were carcinosarcoma and leiomyosarcoma. Of the benign cases, benign endometrial polyp was the most common endometrial lesion and leiomyoma with and without degeneration was the most common myometrial lesion encountered. Of the 50 cases of leiomyoma encountered, 16 had extensive degenerative changes. The most common degeneration seen in the fibroid was hyaline degeneration, and the least common was xanthogranulomatous degeneration. Conclusions The intraoperative frozen section analysis is a very important diagnostic tool, but we need to be aware of its limitations. The accuracy, sensitivity, and specificity rates were found to be high. Thus, frozen section diagnoses can be very valuable in the clinical management of uterine tumors. Careful gross examination, sampling from representative areas, and good communication between the pathologist and surgeon may help in avoiding its limitations.

Leiomyomas are the most common solid benign uterine neoplasms; they are usually asymptomatic and are identified incidentally. Yet, responsive to stimulation by estrogens, leiomyomas may expand, potentially outgrowing their blood supply to undergo hemorrhage, fibrosis, calcification, and atrophy. These pathologic mechanisms commonly lead to leiomyomas degeneration, i.e., red, hyaline, cystic, or myxoid. Magnetic resonance (MR) imaging is the most accurate imaging technique for the characterization of leiomyomas. In cases of degeneration, variable features on T2-weighted and contrast-enhanced images can be found. With no recent radiologic pathologic correlation literature available on this matter, herewith, we provide computed tomography (CT)/MR imaging along with histopathological specimens of two young women who were diagnosed with hyaline or hyaline and cyst degeneration of uterine leiomyomas at our university hospital. We report on the imaging features of uterine leiomyomas using CT and MR imaging and discuss the available literature on imaging signs that may be suggestive of hyaline or cyst degeneration using either of the imaging examination methods.

BACKGROUND: Abnormal uterine bleeding is a common problem encountered by the gynaecologists, leiomyoma being one of the most common causes. An accurate knowledge of the different variants and secondary changes occurring in leiomyoma is essential as some of these may mimic malignancy clinically, radiologically and histologically. Some important examples being atypical, cellular and mitotically active leiomyoma. Similarly, hydropic and myxoid change can be misdiagnosed as malignancy. While dealing with these variants and changes, leiomyosarcoma although a rare tumour has to be excluded because of the difference in management. Hence a comprehensive knowledge of all the variants is mandatory to avoid misdiagnosis.
METHODS: This study was carried out at the Pathology Department of Ayub Medical College Abbottabad where 964 cases of leiomyoma of the female genital tract were studied. These cases were received during the period January 2013 to December 2017.
RESULTS: The most common variant of leiomyoma was cellular leiomyoma while hyaline degeneration was the most common secondary change identified.
CONCLUSIONS: Accurate knowledge of these variants and degenerative changes in leiomyomas are mandatory to prevent misdiagnosis and over treatment along with undue stress to the patient. Secondly it is important to identify variants which require follow-up.

Myxopapillary ependymomas (MPEs) are uncommon and account for ∼15% of all ependymomas. The current study presents a case of rare spinal MPE with abnormal hyaline degeneration. The patient was a 72-year-old male with a 10-month history of lower back pain. Magnetic resonance imaging revealed a mass involving the L4 and L5 vertebrae with local bone destruction. The tumor was completely resected. Histologically, the majority of the tumor exhibited low cellularity. A marked change in hyaline was observed in the blood vessels and stroma. In specific areas, the tumor showed reticular or tubular patterning embedded in hyaline materials. The tumor cells were cuboidal to columnar in shape with strong immunostaining for glial fibrillary acidic protein and S-100. A fluorescence in situ hybridization analysis for amplification of the epidermal growth factor receptor gene was negative. The results of pathological and immunohistochemical studies were consistent with the ependymal nature of neoplastic cells.