Sacrococcygeal Mass, Pediatric



Sacrococcygeal Mass, Pediatric


Kevin R. Moore, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Sacrococcygeal Teratoma


  • Presacral Abscess


Less Common



  • Chordoma


  • Neuroblastic Tumor


  • Plexiform Neurofibroma


  • Lymphoma


  • Chondrosarcoma


  • Ewing Sarcoma


Rare but Important



  • Rhabdomyosarcoma


  • Osteosarcoma


  • Dermoid and Epidermoid Tumors


  • Myxopapillary Ependymoma


  • Anterior Sacral Meningocele


  • Terminal Myelocystocele


  • Enteric Cyst


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Myriad pathologies produce sacrococcygeal masses; clinical data directs differential list


  • Fever, elevated inflammatory markers prompt search for infection source


  • Identification of tumor matrix narrows differential considerations


  • Location and relationship of mass to important regional structures impacts tumor resectability


  • Look for osseous invasion or epidural extension, which may alter surgical planning


Helpful Clues for Common Diagnoses



  • Sacrococcygeal Teratoma



    • Very heterogeneous density/signal intensity, enhancement of solid tumor portions


    • AAP grade based on proportion of external and internal tumor



      • Male sex, large proportion internal tumor, older age at diagnosis portend worse outcome


    • Often detected on routine obstetrical ultrasound ⇒ elective cesarean section



      • Fetal MR valuable for confirmation of diagnosis, AAP grading


    • Sacrum and coccyx usually spared, even when tumor spreads into spinal canal via sacral hiatus


    • Coccyx must be resected or recurrence risk high


  • Presacral Abscess



    • Fever, serum inflammatory markers usually elevated, prompting clinical consideration of diagnosis


    • Regional soft tissue inflammation, discitis, epidural abscess, or vertebral osteomyelitis


    • Rim enhancement and diffusion restriction on DWI MR characteristic


Helpful Clues for Less Common Diagnoses



  • Chordoma



    • Strong predilection for sacrum (50%)



      • Other common locations include clivus (35%) and vertebra (15%)


    • Characteristic very high T2 signal intensity limits differential considerations


    • No tumor matrix (in distinction to chondrosarcoma)



      • Osseous debris within tumor may mimic matrix on CT


  • Neuroblastic Tumor



    • Paraspinal location along sympathetic chain (neural crest derivatives)


    • Benign (ganglioneuroma) → intermediate grade (ganglioneuroblastoma) → highly malignant (neuroblastoma)


    • Frequently calcified, encircles vessels and regional structures


    • Important upstaging findings affecting surgical management include bilaterality and epidural extension



      • MR best imaging modality for detecting tumor extension into spinal canal through neural foramen


  • Plexiform Neurofibroma



    • Neurofibromatosis type 1


    • Grape-like or botryform morphology with characteristic distribution along nerves (major or minor peripheral nerves/plexi)


    • Hyperintense on STIR MR, T2WI MR


  • Lymphoma



    • Protean imaging appearances


    • Often large at diagnosis; may be focal or diffuse


    • Relatively low signal intensity on T2WI MR ± mild diffusion restriction reflects high tumor cellularity



  • Chondrosarcoma



    • Very high T2 signal intensity; may be difficult to distinguish from chordoma on imaging


    • Chondroid matrix (when present, 50%) diagnostic


  • Ewing Sarcoma



    • Usually older child/adolescent presentation age


    • Aggressive or permeative bone destruction


    • Cellular signal intensity (relatively low signal intensity on T2WI MR)


Helpful Clues for Rare Diagnoses

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Sacrococcygeal Mass, Pediatric

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