Muscle Tumors

 

S

677

Figure 116.1 The histological appearance

of a rhabdomyosarcoma, alveolar subtype.

The cells are small, with little cytoplasm with

bland chromatin structures visible.

Figure 116.2 The histological appearance of

a rhabdomyosarcoma, embryonal subtype.

The tumor is composed of numerous round

or spindled cells, either with minimal or

abundant eosinophilic cytoplasm.

NOTES

MUSCLE TUMORS

osms.it/rhabdomyosarcoma

RHABDOMYOSARCOMA (RMS)

▪ Highly malignant tumor arising from

skeletal muscle cells

TYPES

Alveolar

Embrional

▪ Most common, frequently children

▫ Botryoid, spindle-cell

rhabdomyosarcoma

Pleomorphic (anaplastic)

▪ Worst outcome, frequently adults

CAUSES

▪ Genetic translocation determining fusion of

two genes which encode two transcription

factors

▫ FOXO1, PAX3

▪ FOXO1-PAX3 fusion protein interferes

with differentiation-driven gene expression

program → poorer outcome

RISK FACTORS

▪ Syndromes, congenital anomalies (e.g.

Li–Fraumeni syndrome, neurofi bromatosis

type I, Beckwith–Wiedemann syndrome,

Costello syndrome)

COMPLICATIONS

▪ Metastasis

▪ Bone marrow involvement: anemia,

thrombocytopenia, neutropenia

PATHOLOGY & CAUSES

678 OSMOSIS.ORG

Figure 116.3 The gross pathological

appearance of a rahbdomyosarcoma,

embryonal subtype. The tumor is poorly

circumscribed with a fi rm texture and is

cream to white in color.

MEDICATIONS

▪ Polychemotherapy

▪ Immunotherapy

SURGERY

▪ Resection

OTHER INTERVENTIONS

▪ Radiation therapy

TREATMENT

▪ Palpable mass

▫ Localization: head/neck, genitourinary

tract, limbs, abdomen

▪ Depending on tumor size

▫ Hematuria, urinary obstruction

(genitourinary tract involvement)

▫ Sinusitis, headache, cranial nerve

alterations, ear discharge, orbital

swelling (head involvement)

SIGNS & SYMPTOMS

DIAGNOSTIC IMAGING

X-ray, CT scan, MRI, ultrasound

▪ Determines local invasion, metastasis

LAB RESULTS

▪ Liver, renal function tests

▪ Complete blood count

▫ Anemia, pancytopenia

▪ Biopsy

▫ Microscopic analysis

▫ Immunohistochemical studies showing

muscle tissue-characteristic proteins