A 19-year-old female presented with a swelling in her left upper thigh that had been growing for six months. MRI imaging showed an ill-defined heterogeneous lesion in her left upper thigh muscles. A biopsy was performed and found scanty cellular smears with elongated cells in a myxoid matrix, suggesting giant cell tumor or malignant schwannoma. During surgery, a 12x6cm tumor was found involving two thigh muscles and removed. Histopathological examination found the rare malignant Triton tumor, a malignant peripheral nerve sheath tumor with rhabdomyoblastic differentiation. This case report presents this extremely rare tumor found in the patient's thigh.
1. HISTOLOGICAL STUNNER
WITHIN A THIGH SWELLING OF
A YOUNG FEMALE
TRITON TUMOR
PRESENTOR- Dr. RAJESHWARI, POST GRADUATE
GUIDE-Dr. THIRUMURUGANAND MS
GOVERNMENT CHENGALPATTU MEDICAL COLLEGE.
2. CASE REPORT
• A 19 year old female presented with a swelling in the upper
one third of left upper thigh for six months.
• There was no history of any antecedent trauma or infection.
• The general examination revealed no abnormalities.
• On examination, it appeared to be a non-tender firm soft
tissue mass measuring about 8*6 cm in size.
• There was no restriction of movement of the thigh.
3. • MRI imaging of the thigh showed an ill defined heterogenous
lesion with T2 hypo to iso intensity lesion noted in the
intramuscular plane of lateral part of left upper thigh and
causing mass effect over the vastus lateralis muscle medially.
• And few internal flow voids noted with in lesion showing
restricted diffusion and gave the impression as SOFT TISSUE
SARCOMA.
• FNAC showed scanty cellular smears composed of elongated
population of cells having elongated nucleus in the background
of myxoid matrix and gave GIANT CELL TUMOR AND
MALIGNANT SCHWANNOMA as two possibilities.
4. Intra operative findings
• Tumour of 12*6cm found to involve vastus lateralis and vastus
intermedialis muscle.
• Tumour resected in toto along with 2cm clearance on all margin
5. • The specimen sent to pathological department
for histopathological examination.
7. Malignant Triton tumor
• Malignant peripheral nerve sheath tumour with rhabdomyoblastic differentiation.
• Relatively rare,aggressive tumor made up of both malignant schwannoma cells and
malignant rhabdomyoblasts.
• Fewer than 200 cases in literature.
• Originally described by Masson in 1932.
• The unusual name ‘triton’ was first used in reference to observation of supernumerary
limbs containing bone and muscle growing on the backs of triton salamanders after the
implantation of sciatic nerve tissue the so called “locatellis experiment”
8. • Two thirds of the tumor generally associated with Neurofibromatosis 1 and other form is
sporadic.
• Tumor not associated with NF1 have worst prognosis.
• MTT has a poor prognosis owing to its aggressive behaviour.
• Radical excision followed by high dose radiotherapy is the conventional mode of treatment.
• The prognosis of MTT depends on the location,size of the tumor,grade and completeness of
surgical margins.
• This case is presented for its extreme rarity.
