Histopathological Spectrum of Leiomyoma of the Uterus with an Emphasis on Pathological Technique to Avoid the Misdiagnosis: A Single Tertiary Centre Experience

Background: The most typical uterine tumour that develops from smooth muscle is a leiomyoma. It might be challenging to provide an accurate diagnosis when it exhibits abnormal gross features or artefacts. The fixation, grossing, taking sections, tissue processing, sectioning and staining are all aspects that might alter the histological spectrum, which varies from benign to malignant. Therefore, careful consideration must be given to all advantages and disadvantages in specimen handling, processing, evaluating gross examination and obtaining sections to arrive at a definitive diagnosis. Aims: To identify the pathological factors that affect the diagnostic accuracy in resection specimen of uterine mass, clinico-radiologically suggestive leiomyoma. Patients: All female patients (352) who underwent surgery for clinically suggestive uterine leiomyoma in a period of two years were included in the study. Materials and Methods: It was a retrospective observational study in a tertiary care centre that spanned 2 years, from January 2019 to January 2021. All patients who had undergone surgery for leiomyoma in this duration were included. All big specimens underwent customised pathology techniques. Results: A total of 352 cases, including 348 leiomyomas, three uterine smooth-muscle tumours of uncertain malignant potential (STUMP) and one case of leiomyosarcoma, were studied. A majority of patients were in the age group of 36–45 years (49.04%). Total hysterectomy was the most common type of surgery performed for leiomyoma (62.06% cases). The most common site of occurrence is intramural. The average size of leiomyoma was 4.72 cm. A majority (88.21%) of leiomyomas were of typical type without any degeneration or variation in histology. Hyalinised collagen (5.75%) is the most frequent finding encountered as a histopathological variant, followed by myxoid change (1.43%). Associated pathology with leiomyoma was adenomyoma (10.91%), followed by uterine malignancy. Adopting the pathology techniques, three cases of uterine smooth-muscle tumours of uncertain malignant potential (STUMP) and one case of leiomyosarcoma could be identified. Conclusion: A pathologist needs to be skilled in troubleshooting lacunae, whether they are caused by fixing the gross or by cutting sections and staining tissue processing. These variables affect the accuracy of the diagnostic process.