Fig. 5

A 53-year-old male patient with NHL- diffuse large B cell type underwent splenectomy and received chemotherapy presented by peri-anal swelling. CT (a), PET (b), and PET/CT (c) revealed FDG- avid peri-pancreatic/caeliac LNs with each other are also seen and measures about (6.2 × 4.8 cm) with SUV 22). CT (d), PET (e), and PET/CT (f–i) show metabolically active pre-coccygeal mixed cystic and solid soft tissue mass with few calcific foci seen inside, infiltrating the posterior and lateral walls of the rectum and anal canal encroaching upon the posterior aspect of the colon, and the prostate and extends to the overlying skin and subcutaneous tissue of the gluteal region and measures about 8.7 × 7.5 × 16 cm in dimensions with inhomogeneous FDG tracer fixation of its solid components and SUVmax 10.6. MIP PET image (j) confirms the findings. US-guided core biopsy of pre-coccygeal mass on revealed anaplastic adenocarcinoma and patient received chemotherapy