140	P. Imbach

–Indolent mass; often large tumor at diagnosis

–Symptoms of spinal compression

–Dyspnea (differential diagnosis: pulmonary metastases)

12.2.5.4Retroperitoneal Area

• Frequency 7%

• Symptoms:

– Mostly a large tumor mass prior to first symptoms

– Abdominal pain resembling appendicitis

– Tumor mass with or without ascites

12.2.5.5Rare Locations

•Biliary tract (frequency 3%)

–Symptoms as in cholecystitis

–Hyperbilirubinemia

•Intrathoracic (frequency 2%)

•Perineal area (frequency 2%)

12.2.6Laboratory Diagnosis

•Besides biopsy of the tumor including material for electron microscopic analysis, fresh material is necessary; needle biopsy is not recommended

•Specific laboratory analyses depend on location of the tumor:

–General blood and serum analyses, urine analysis

–Bone marrow aspiration and biopsy

–Lumbar puncture for cerebrospinal fluid analysis

12.2.7Radiological Diagnosis

•Conventional X-ray imaging

•Ultrasonography

•Magnetic resonance imaging (MRI) preferable to computed tomography (CT), consider PET scanning.

•Bone scan

12.2.8Staging/Grouping

•The Intergroup Rhabdomyosarcoma Study (IRS) group distinguishes between:

–Local extension

–Postsurgical residual tumor mass

–Local and distant metastases

12 Soft Tissue Sarcoma	141

Clinical staging and grouping according to Intergroup Rhabdomyosarcoma Study (IRS)

IA Localized tumor, confined to site of origin, completely resected

B Localized tumor, infiltrating beyond site of origin, completely resected

IIA Localized tumor, gross total resection, but with microscopic residual disease B Locally extensive tumor (spread to regional lymph nodes) completely resected

C Extensive tumor (spread to regional lymph nodes, gross total resection, but with microscopic residual disease)

IIIA Localized or locally extensive tumor, gross residual disease after biopsy only

BLocalized or locally extensive tumor, gross residual disease after major resection (50% debulking)

IV	Any size of primary tumor, with or without regional lymph node involvement,
	with distant metastases, irrespective of surgical approach to primary tumor
Stage	Frequency (%)
I	16
II	20
III	48
IV	16

•In addition, TNM staging:

–Tumor extension

–Lymph node involvement

–Metastases

TNM staging correlated with Intergroup Rhabdomyosarcoma Study (IRS)

Stages	Prognosis	Sites	Tumor		Tumor size	N	M
	(%)		invasiveness
I	>90	Orbit, head and neck,	T1 or T2		All	N0, N1,	M0
		genitourinary				Nx
		(nonbladder/
		nonprostate)
II	80–90	Bladder/prostate,	T1	or T2	£5 cm	N0, Nx	M0
		extremities, cranial
		parameningeal, other
III	70	Bladder/prostate,	T1	or T2, T1 or	£5 cm,	N1, N0,	M0, M0
		extremities, cranial,	T2		>5 cm	N1, Nx
		parameningeal, other
IV	30–40	All	T1	or T2	All	N0, N1	M1

T1 limited to organ of origin, T2 expansive tumor size, N (regional lymph nodes): N0 negative, N1 positive, Nx unknown

12.2.9Metastatic Spread

•Metastases via lymphatic and/or hematogenous spread

•Variable frequency of metastases in relation to localization of the primary tumor (see below, under “Special Locations”)