Male patient in his second decade presents with huge thigh mass.
Touch preparations stained with Diff Quick showed :
- Fibrillary to myxoid metachromatic stroma.
- The cells show plumpy hyperchromatic nuclei with moderate pleomorphism some intranuclear pseudoinclusions are also noted.
- Nerve sheath differentiation in the form of elongated, slender wavy nuclei.
- Scanty cytoplasm.
On Histopathology the case was diagnosed as Malignant Peripheral Nerve Sheath Tumor.
The morphological features of MPNST are very variable. The 2 most common patterns are the spindle cell and epithelioid cell patterns. Cases showing fibromyxoid like morphology and Hemangiopericytoma like features are reported.
“The majority of MPNST are diagnosed as spindle cell sarcoma or pleomorphic sarcoma with FNA. The cellular features may suggest MPNST but a diagnosis may be difficult, even with the help of adjunctive methods. IC may be of diagnostic help if S-100 protein is positive. The positivity in MPNST is typically focal, extensive staining favours a cellular schwannoma. negative staining with desmin, SMA and muscle-specific actin excludes smooth muscle tumours and negative staining with cytokeratin, EMA and CD99 excludes synovial sarcoma”. The Cytology of Soft Tissue Tumours Dr. Mi1ns Akerman Dr. I-Ienryk A. Domanski
Helpful features include sharp radiating pain in FNA aspiration, Relation with major nerve trunk and history of Neurofibromatosis type 1 .
(By courtesy of Dr. Hatim Khoja)
GCTTS is a very common Benign tumor usually affecting the digits in females ( 2x more common) grossly it is a lobulated small (2-3 Cm.) yellowish mass.
Here in our case we can see :
- osteoclast like gaint cells with many bland looking nuclei.
- many mononuclear cells in the back ground.
- Not much inflammatory cells or hemosidren.
The differential here:
- pigmented villonodualr tenosynovitis – usually in large joints like knee with lots of hemosidren.
- other granulomatous lesions – many inflammatory cells.
- mononuclear cells stain with Desmin
- you may see necrosis , tumor thrombi on paraffin sections.
Neoplastic vs reactive nature is still one of the questions to be solved.
-Long slender tapering nuclei sometimes bend and form hooks and comma shapes.
– Fibrillari back ground.
– Watch out from degenerative changes which including pleomorphism.
– If you find verocay bodies you are lucky
This case is dedicated to our dear colleague and friend Ahmed AboSolb, leaving us soon. your case is solved from the very first day 🙂