Patient presents with [chief complaint related to retroperitoneal mass; e.g., abdominal pain, flank pain, abdominal distension, palpable mass, weight loss, or incidentally discovered on imaging].  Review of systems reveals [positive findings; e.g.,  nausea, vomiting, early satiety, change in bowel habits, hematuria, or no significant findings].  Past medical history includes [relevant medical conditions; e.g., hypertension, diabetes, prior abdominal surgeries, or family history of cancer].  Physical examination reveals [objective findings; e.g., palpable abdominal mass, tenderness to palpation, abdominal distension, or normal abdominal exam].  Imaging studies, including [CT scan, MRI, ultrasound, or PET scan], demonstrate a retroperitoneal mass measuring [size] cm located [location; e.g.,  adjacent to the kidney, pancreas, or aorta].  Differential diagnosis includes [lipoma, liposarcoma, leiomyosarcoma, lymphoma, neurogenic tumor, germ cell tumor, metastatic disease, or other retroperitoneal neoplasms].  Laboratory studies, including [complete blood count, comprehensive metabolic panel, tumor markers such as AFP, beta-hCG, LDH if indicated], are pending or show [results].  The patient was counseled on the potential need for biopsy or surgical resection for diagnostic and therapeutic purposes.  Risks and benefits of the procedures were discussed.  Patient understands the plan and will follow up for further evaluation and management of the retroperitoneal mass.  The plan includes [referral to surgery, oncology, or other specialties as indicated].  ICD-10 code [D48.3 - Neoplasm of uncertain behavior of retroperitoneum and peritoneum] and CPT codes for imaging and procedures performed will be used for medical billing and coding.  Further evaluation and management will be based on biopsy results and final diagnosis.