Lipomatous lumbar mass with an attached digit and associated split cord malformation.
BACKGROUND
A male infant was born with a digit attached to a skin-covered lumbar lipomatous mass and an underlying split cord malformation.


METHODS
Surgical removal of the mass was performed at four months-of-age. By this time the digit had grown a nail and imaging and histology showed ongoing development of articulated phalanges.


RESULTS
The lipomatous mass contained a long bone, a clavicle- and scapula-like structure and a variety of other mature germ layer derivatives. These features raised a number of diagnostic considerations, including: mature teratoma, hamartoma, rudimentary parasitic twin, lipomyelomeningocele and dorsal accessory limb.


CONCLUSIONS
Based on review of the literature, the authors hypothesize that there is a pathogenetically related spectrum of skin-covered dorsal mass lesions, often associated with spinal dysraphism. These consist of a major lipomatous component and a variety of mature germ layer derivatives that can vary widely in their degree of anatomical organization from case to case.
Department of Pathology and Molecular Medicine, Queen's University and Kingston General Hospital, Kingston, Ontario, Canada.
C M H
CM
Snelling
P M
PM
Ellis
R M L
RM
Smith
J P
JP
Rossiter
D000328:Adult; D005260:Female; D006801:Humans; D008067:Lipoma / Q000150:complications* / Q000473:pathology; D008159:Lumbar Vertebrae / Q000002:abnormalities*; D008279:Magnetic Resonance Imaging / Q000379:methods; D013116:Spinal Cord / Q000002:abnormalities*; D013120:Spinal Cord Neoplasms / Q000150:complications* / Q000473:pathology