Date of Presentation:5/07/2021

Attending pathologist: Paul E. Wakely Jr., MD

Presented by: Ashley Patton, DO, PhD

Prepared by: Ashley Patton, DO, PhD

Organ:Bone and Soft Tissue


45 year old female with a history of a left lateral thigh mass. Ultrasound reveal a large heterogeneous mixed echogenic solid cystic hypoechoic lesion anterior to the left hip joint likely represents a large complex collection/hematoma. Possibility of a neoplastic lesion cannot be entirely excluded.

Magnetic resonance imaging (MRI) demonstrated a large 9.8 x 12.1 x 14.3 cm complex collection in the left lateral thigh. Imaging characteristics were be consistent with a hematoma although underlying neoplastic process is difficult to completely exclude.


Gross: The specimen is designated as “left thigh mass” and consists of a 1,111 gram, 15.5 x 13.2 x 13.1 cm cystic mass with attached yellow-pink soft tissue. Cut section through the mass reveals extensively necrotic tissue, approximately 75% cystic and 25% solid.  Areas of necrosis appear to occupy approximately 90% of the mass.  The cystic component is filled with blood-tinged mucinous material.  The solid component of the mass is pink-white and gelatinous.  

What is the most likely diagnosis?

  1. Leiomyosarcoma
  2. Malignant peripheral nerve sheath tumor
  3. Spindle cell rhabdomyosarcoma
  4. Dedifferentiated liposarcoma
Malignant peripheral nerve sheath tumor