Parosteal lipoma of proximal radius-A rare case report

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Parosteal lipoma of proximal radius-A rare case
report

• Presenting author Dr.Bursupalle Mahesh Reddy
  mdrd pg
• CoauthorDr.Onteddu Joji Reddy,mdrd,profhod
• Dept of Radiodiagnosis
• Kurnool Medical College
• Kurnool
• Andhra Pradesh

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INTRODUCTION

• Parosteal lipoma is an extremely rare benign
  tumor
• composed mainly of mature adipose tissue with a
  bony
• component.
• The most common locations for this tumor are the
  femur,
• proximal radius, humerus, tibia, clavicle and
  pelvis.
• It affects, almost exclusively, adults over 40
  years, of either sex.

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AIM

• It is among the rarest neoplasias of skeleton,
  accounting
• for less than 0.1 of primary bone tumors and
  0.3 of all lipomas.
• To convey its rarity ,benignity and extreme rare
  malignant
• transformation and complete cure after
  resection,iam
• presenting this as case report.

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MATERIALS AND METHODS

• A 80 yr old male patient presented with a
  painless swelling on the proximal part of the
  left forearm.
•  The swelling was a slow growing, painless,
  nontender, immobile mass which was not fixed to
  skin.

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•  X-ray showing radiolucent shadow of fat density
  with bony excrescences adherent to left proximal
  radius.
• CECT showing non enhancing hypodense lesion of
  fat density with  osseous excrescences abutting
  the left proximal radius .

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• MRI revealed a large well defined, nonenhancing,
  heterointense, predominantly fat intensity lesion
  with a small area of signal loss corresponding to
  calcification in lateral aspect of proximal left
  radius, seen completely separate from the
  adjacent muscles.

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RESULTS

• The tumor was resected along with periosteum and
  then sent to biopsy.
• Biopsy revealed both osteal and fat components.

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DISCUSSION

• Parosteal lipoma is situated directly on the
  cortex of bone.
• Thought to arise from mesenchymal cells in the
  periosteum, parosteal lipomas share
  histopathologic features with the commonly
  occurring soft-tissue lipomas, and cytogenetic
  evidence suggests a common histopathogenesis

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• Depending on the degree of chondroid modulation
  and enchondral ossification
• 1. parosteal lipomas may rest directly on the
  cortex without cartilage or bone elements
• 2. may have a narrow bony stalk with a lucent
  lipomatous cap, mimicking a pedunculated
  exostosis

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• 3.may have a densely ossified broad-based
  osteochondromatous element beneath a thin
  lipomatous cap, simulating a sessile exostosis
• 4.may have patches of chondroid and bone
  scattered throughout the lipomatous mass.

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• On CT and MR imaging, parosteal lipomas have a
  homogeneous lobulated appearance and are adherent
  to the surface of the adjacent bone.
• When present, osseous excrescences may mimic
  osteochondromas, but the former lack the
  contiguity of the marrow space with the
  underlying bone that is characteristic of the
  latter.

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• Parosteal lipomas that gain clinical attention
  are those that compress neurovascular bundles and
  cause motor and sensory function deficits
• . Common sites of involvement include the
  proximal forearm and the sciatic nerve.

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• The treatment of parosteal lipoma is complete
  surgical resection along with periosteum.
• The nerve must also be separated from the
  parosteal lipoma and care must be taken to spare
  it during surgical excision.

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CONCLUSION

•       These soft tissue tumors are benign with
  extremely rare malignant transformation and an
  excellent prognosis with no recurrence.

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T1w image coronal view showing hyperintense
lesion with signal void adherent to left proximal
radius
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IRFSE image axial view showing fat suppression
with signal void adherent to left proximal radius
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 X-ray showing radiolucent shadow of fat density
with bony excrescences adherent to left proximal
radius.
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CT showing hypodense lesion of fat density with
 osseous excrescences abutting the left proximal
radius .