Congenital Smooth Muscle Hamartoma



Congenital Smooth Muscle Hamartoma


Steven D. Billings, MD





Key Facts


Terminology



  • Rare lesion presenting in infants, characterized by disorganized proliferation of benign smooth muscle bundles in dermis, often involving subcutis


Clinical Issues



  • Infants


  • Most common in lumbosacral area


  • Macule or plaque


  • Often hyperpigmented, may have coarse hairs


Microscopic Pathology



  • Benign smooth muscle bundles



    • Haphazard arrangement


    • Thin fascicles rather than solid growth pattern


    • No atypia


    • No mitoses


    • No necrosis


    • Immunohistochemistry (+) for muscle markers







Congenital smooth muscle hamartoma shows a haphazard arrangement of smooth muscle bundles present throughout the dermis.






High magnification shows a fascicular arrangement of smooth muscle with characteristic elongated, spindle-shaped to blunt-ended nuclei image.


TERMINOLOGY


Synonyms



  • Smooth muscle hamartoma


Definitions



  • Rare benign smooth muscle tumor presenting in infants


  • Characterized by disorganized proliferation of smooth muscle bundles


CLINICAL ISSUES


Epidemiology



  • Age



    • Infants


Site



  • Lumbosacral area and proximal extremities


Presentation

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Jul 8, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Congenital Smooth Muscle Hamartoma

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