Sarcopedia

Benign fibromyxoid tumour with predilection for subungual and periungual regions Lesions are prone to local recurrence

Abnormal vaginal bleeding Pelvic pain Polypoid mass protruding through the cervical os

Extremely rare malignancy Diagnosis of exclusion - must rule out other sarcoma variants Spindle shaped fibroblasts in herringbone formation Grade determines prognosis and treatment Radiologic-pathologic correlation is essential

Highly aggressive rhabdomyosarcoma characterized by primitive, round cells showing skeletal muscle differentiation Older age of presentation than embryonal type Higher metastatic potential

Deceptively slow-growing despite high-grade histology Metastatic propensity (43% at presentation) TFE3 rearrangement is diagnostic Long-term surveillance required - late metastasis well recognised

Benign deep soft tissue or viscerally located benign vascular neoplasm, often discovered incidentally Unclear aetiology may appear in context of chronic kidney disease and renal cell carcinoma Mimics well differentiated angiosarcoma radiologically and histologically

Benign lesion located in the soft tissues of the extremities, often in association with joints or fibrotendinous structures

Pain is a cardinal feature - often out of proportion to size Female predominance and lower extremity location are characteristic Must be distinguished from leiomyosarcoma (which is rare in subcutaneous tissue) Simple excision is curative

Painful subcutaneous mass is the classic presentation Often multiple on forearms in young men Fibrin microthrombi are pathognomonic

Can mimic haematoma or cyst clinically and radiologically EWSR1 rearrangement is diagnostically useful Paraneoplastic symptoms resolve after excision Intermediate classification

Benign vulvovaginal tumour in reproductive-age women Must be distinguished from aggressive angiomyxoma (which is infiltrative) Simple excision curative

Unique to the soft tissues of the lower genital tract, pelvis and perineum Local recurrence in 30% but distant metastasis and death from disease are exceptionally rare Clinical follow-up recommended

Rare aggressive Vascular malignancy Early metastatic spread typical Poor prognosis despite treatment Paclitaxel shows benefit in angiosarcoma

High-flow vascular malformation - distinguish from haemangioma (low-flow) Pulsatile mass with bruit is classic Angiography is gold standard for characterisation

MDM2 amplification is the key diagnostic marker Extremity ALT has no metastatic potential (but can recur locally) Retroperitoneal location has significantly worse prognosis Terminology: ALT in extremity, WD liposarcoma in retroperitoneum

Represents a spectrum between benign neurofibroma and MPNST CDKN2A loss and H3K27me3 loss are molecular markers of progression FDG-PET useful to identify lesions at highest risk of malignant transformation in NF1 Diagnosis requires careful pathological assessment

Benign intraneural proliferation composed of mature peripheral nerve and interspersed muscle Pathogenesis unclear, no aetiologic associations known

Fibroblastic tumour occuring in children and young adults Seen primarily on hands and feet Stippled calcifications on imaging are characteristic High local recurrence rate Locally aggressive but does not metastasise

Benign genital/inguinoscrotal soft tissue tumour RB1 loss is characteristic Simple excision curative

Rare high-grade round cell sarcoma More aggressive than Ewing sarcoma Often affects young adults in deep soft tissues

Distinct entity from cutaneous melanoma despite similar IHC profile EWSR1 rearrangement essential for diagnosis - melanoma lacks this Lymph node involvement more common than most STS - sentinel node biopsy should be considered Foot/ankle location in young adults is characteristic

Rare vascular neoplasm with small risk of malignant potential Composite of multiple haemangioendothelioma patterns Wide age distribution and location

High-grade liposarcoma with a mixture of well differentiated regions and non-lipogenic spindle cell or pleomorphic sarcoma MDM2 amplification High rate of local recurrence as well as metastatic disease to lungs

Large infiltrative pelvic mass in reproductive-age women Swirling MRI pattern characteristic High local recurrence - long-term surveillance essential No metastatic potential

Deep soft tissue counterpart of dermal fibrous histiocytoma Locally aggressive - wide excision needed Low but real metastatic risk

Benign neural tumour of dermis Lobulated myxoid nodules Simple excision curative

Intermediate-grade fibroblastic tumour of the dermis "Honeycombing" of fat is a key pathologic feature Requires wide local excision to prevent recurrence. Mohs surgery achieves best local control for facial lesions Requires long-term follow up

Locally aggressive, non-metastasising fibroblastic neoplasm Relentless local infiltration and a high propensity for recurrence Watch-and-wait is now first-line management for most asymptomatic/stable lesions CTNNB1 mutation type predicts recurrence risk Screen for FAP when intra-abdominal/mesenteric desmoid is diagnosed Sorafenib is currently the most active systemic treatment

Benign collagenous tumour FOSL1 rearrangement is defining Simple excision curative - no recurrence

EWSR1-WT1 fusion is pathognomonic Young males with peritoneal disease Multilineage IHC expression (expresses markers of all three germ layers: epithelial, mesenchymal, and neural Very poor prognosis

Occurs exclusively in immunocompromised patients EBV EBER positive is diagnostic Multiple lesions across organs is characteristic Immune restoration is primary treatment

Mixed neural and rhabdomyoblastic tumour Children most affected Treated like high-grade rhabdomyosarcoma

Extracranial meningioma - rare Scalp and orbit most common sites Histologically identical to intracranial meningioma

Virtually always in subscapular region - unique anatomical predilection Imaging characteristics alone are diagnostic in appropriate clinical setting - biopsy rarely needed Bilateral in majority - always examine opposite side Elderly women with repetitive shoulder activity (scrubbing, climbing) classically affected

Cytokeratin positivity is a diagnostic pitfall - may be confused with carcinoma or mesothelioma CD31 and ERG are the most sensitive Vascular markers MYC amplification confirms radiation-association Management as per conventional angiosarcoma

Loss of INI1 (SMARCB1) on IHC is diagnostically key Tazemetostat (EZH2 inhibitor) is the first targeted therapy approved for this disease Proximal type is more aggressive and carries worse prognosis than distal/classic type Lymph node dissection or sentinel node biopsy should be considered

Acral soft tissue tumours Emerging entity in WHO 5th edition EWSR1-SMAD3 fusion is defining ERG positive - can mimic vascular tumour

INI1 loss is diagnostic Infants and young children Screen for germline SMARCB1 mutation Extremely poor prognosis

NR4A3 rearrangement is pathognomonic Indolent course - long survival even with metastases Late metastasis - long-term surveillance essential Large deep thigh/limb girdle tumours

Bone formation in soft tissue is key diagnostic feature Younger adults than typical soft tissue sarcomas Aggressive with metastatic potential

Slow-growing, painless mass Systemic symptoms (fever, weight loss) are rare unless the disease is advanced

Benign fibrous nodule on tendon sheath Finger and hand predilection Simple excision curative

Neonatal SCM tumour - physiotherapy first-line Associated with birth trauma Resolves spontaneously in most - avoid unnecessary surgery

Benign hamartoma of infants Axilla is classic location Often no treatment needed

Benign fibromatosis variant Associated with familial adenomatous polyposis

KIT mutations define GIST Risk stratification guides treatment Tyrosine kinase inhibitors transforming prognosis

Pediatric version of DFSP; shares the same "tentacle-like" growth pattern Presence of angiectoid (vessel-like) spaces is a hallmark feature Requires long-term monitoring as it can recur as classic DFSP

Rare Malignant variant of hemangiopericytoma High-grade malignancy with aggressive course

Classic clinical triad in subungual lesion is virtually diagnostic X-ray may show distal phalanx erosion - subtle but important finding MRI is investigation of choice for precise localisation pre-operatively Malignant variant characterised by large size (>2 cm), deep location, and nuclear atypia

Benign Neural tumour Rarely undergo Malignant transformation

Benign brown fat tumour Often in 'brown fat depots': interscapular, axilla, mediastinum, neck Simple excision is curative

ETV6-NTRK3 fusion defines infantile fibrosarcoma - shared with mesoblastic nephroma NTRK inhibitors are transformative - larotrectinib has 75% response rate in TRK fusion-positive tumours Prognosis far better than adult fibrosarcoma despite aggressive histology Active surveillance/watch-and-wait being explored for very young infants

Rare genetic Fibrous disorder Autosomal recessive CMG2 mutations Multiple progressive lesions from infancy Management focuses on complications No curative treatment currently available

No summary available yet.

Majority present in infancy to teenage years 50% in the first year of life

Benign smooth muscle tumour No Malignant transformation

Second most common STS Often presents at advanced stage Grade and depth crucial for treatment planning Regular imaging Follow-up essential

Embryonal fatty tumour of infants Benign despite somewhat immature appearance

Most common Benign soft tissue tumour No Malignant transformation

Benign proliferation of multiple lipomas No Malignant transformation

Most common STS in adults Subtype determines behaviour and prognosis Wide excision is mainstay of treatment Follow-up imaging critical for detection of recurrence

Benign lymphatic malformation Often congenital but can present later Observation reasonable if asymptomatic Excellent prognosis with appropriate management

High-grade malignancy Screen for NF1 Multimodal therapy standard NF1 association worsens prognosis

Benign developmental heterotopia Requires excision for confirmation

Tumour of perivascular epithelioid cells Fat-containing lesion in kidney characteristic TSC association in some cases

Highest-grade liposarcoma variant Aggressive behaviour - multimodal therapy required

Adult variant - generally poor prognosis Aggressive behaviour requiring multimodal therapy

Acral presentation with multifocal lesions typical Locally aggressive despite Benign appearance Wide excision essential

Benign muscle tumour No transformation to rhabdomyosarcoma

Most common soft tissue sarcoma in children PAX-FOXO1 status defines risk stratification Multimodal therapy standard

Low-grade appearance but aggressive behaviour Wide margins essential due to recurrence risk EWSR1-CREB3L1 fusion is diagnostic

Extraskeletal Ewing sarcoma is biologically identical to Bone Ewing - treated with same protocols CD99 is Highly sensitive but not specific - EWSR1 FISH required for definitive diagnosis RNA-seq increasingly replacing FISH for fusion detection Large tumour volume and metastases at presentation are adverse prognostic factors

Benign soft tissue Cartilage tumour Common in hand and foot

Intermediate-grade with Variable behaviour Risk assessment scheme guides treatment NAB2-STAT6 fusion diagnostic

Pathognomonic association with chronic lymphoedema MYC FISH useful to confirm diagnosis and distinguish from Benign Vascular proliferations Multidisciplinary management involving oncology, plastic surgery, and lymphoedema specialists essential Prevention: optimal lymphoedema management post-mastectomy

t(X;18) EWSR1-SS18 fusion diagnostic Multimodal therapy standard High-grade malignancy despite small appearance

Formerly called PVNS - now classified as diffuse TGCT Haemosiderin deposition causes characteristic low signal on T2 MRI - 'blooming' on GRE is pathognomonic Total synovectomy is surgical treatment but with high recurrence Pexidartinib is FDA-approved and can achieve durable disease control

Most common tumour of tendon sheath - palmar surface of digits is classic location Low signal on T1 and T2 MRI due to haemosiderin is characteristic Pexidartinib (CSF1R inhibitor) is FDA-approved for symptomatic unresectable TGCT Complete excision of all lobules is key to reducing recurrence

Rare vascular tumours of childhood Associated with Kasabach-Merritt phenomenon - life-threatening coagulopathy Sirolimus is current treatment of choice GLUT1 negative distinguishes from infantile haemangioma

Diagnosis of exclusion - must rule out specific sarcoma subtypes Previously called Malignant Fibrous histiocytoma (MFH) Always exclude MDM2 amplification to rule out dedifferentiated liposarcoma Managed with wide excision ± radiotherapy ± chemotherapy

Soft compressible mass that increases with vavlsalva Phleboliths on imaging are characteristic T2 very bright on MRI - low-flow lesion Sclerotherapy is primary treatment for large lesions