Myocystic calcific nodularity: an incidental finding on PET-CT: a case report

Abstract Background Cysticercosis, caused by the larval forms of Taenia solium or Taenia saginata , remains a global public health concern, particularly in developing regions where sanitation and animal husbandry practices are suboptimal. Differentiating benign calcified parasitic lesions from malignant or metastatic deposits on imaging can pose a diagnostic challenge in oncology patients. This case report highlights an incidental finding of residual calcified myocysticercosis in a patient undergoing FDG PET-CT for rectal adenocarcinoma, underscoring the role of imaging in avoiding misinterpretation of benign lesions as metastases. Case presentation A 73-year-old male from a rural background with chronic pork consumption presented with rectal bleeding. Colonoscopy and biopsy confirmed rectal adenocarcinoma. Pelvic MRI revealed circumferential wall thickening involving the upper and mid-third of the rectum with mesorectal and pelvic lymphadenopathy. Following neoadjuvant chemotherapy, F-18 FDG PET-CT performed for response assessment showed metabolically active rectal wall thickening with nodal disease, and multiple metabolically inactive, calcified intramuscular nodules in the anterior abdominal wall and bilateral lower limbs. These were consistent with residual calcified myocysticercosis. No serological or clinical evidence of active parasitic disease was noted, and no specific treatment was required. Conclusion This case emphasizes the importance of recognizing imaging features of benign calcified parasitic lesions to avoid diagnostic confusion with metastatic disease. Awareness of such incidental findings, particularly in patients from endemic regions, prevents mis-staging and unnecessary interventions.