Facile Access to Solifenacin Impurity K: One-Step Synthesis and an HPLC-MS Method for Its Determination.

Solifenacin (SFC) is a potent muscarinic antagonist that effectively reduces bladder muscle contraction, thereby alleviating symptoms such as frequency of micturition and urgency. Oxidation of SFC leads to the formation of impurities like Impurity K. Effective analysis and control of this impurity is crucial for ensuring compliance with regulatory standards and safeguarding patient health.

Cholesterotic fibrous histiocytoma: Case report and literature review.

Cholesterotic fibrous histiocytoma is a particularly rare variant of dermatofibroma that is distinguished histopathologically by the presence of prominent cholesterol deposits within the lesion. We report the case of a 54-year-old male with poorly controlled hyperlipidemia who presented with a firm violaceous papule on the right shin, diagnosed as a cholesterotic fibrous histiocytoma. We also review and summarize the existing literature on this uncommon entity.

Rare Presentation of a Rare Cutaneous Neoplasm: Nonacral Sclerosing Perineuroma.

Sclerosing perineuromas are rare, benign peripheral nerve sheath tumors classically reported on the fingers and palms of young men. We present the case of a 12-year-old boy with a slow-growing nodule on his right knee. Excision was performed, and pathology was consistent with a sclerosing perineuroma.