SOFT TISSUE TUMOURS

Question 1

Desc the risk factor of lipoma and liposarcoma.

Answer 1

• Lipoma usually present in mid adulthood especially 4th to 5th decade of life.
• Mainly occur in female than male
• While, liposarcoma always occur during adulthood mainly age 50s to 60s

Question 2

Desc the aetiology of lipoma and liposarcoma.

Answer 2

• Genetics where amplification of chromosome region 12q13-q15, which includes MDM2 gene.
• This MDM2 gene encodes a potent inhibitor of p53
• T(12:16) resultant in fusion gene that arrests adipose differentiation.
  Lead to complex karyotypes.

Question 3

Desc the pathogenesis of lipoma and liposarcoma.

Question 4

Desc the morphology of lipoma and liposarcoma.

Answer 4

NORMAL: thin cell membrane that bounds the cytoplasmic lipid, which appears clear,, nucleus is pushed to one side by the lipid,, protective tissue septae divide lobules of fat and carry the vascular supply

LIPOMA

1. MACROSCOPIC (GROSS)
   - round to oval
   - well- circumscribed, encapsulated
   - soft, glistening/greasy, lobulated
   - homogenous yellow mass
2. MICROSCOPIC
   - Well defined edge
   - sheets of uniform mature adipocytes
   - no atypia
   - eccentric nuclei- adipocytes have small nucleus which have been displaced to the periphery of the cell by large globule of lipid in the cytoplasm

LIPOSARCOMA

1. MACROSCOPIC (GROSS)
   - Large mass, round- oval shape
   - Yellow- white, lobulated surface
   - Not encapsulated
   - Haemorrhagic spots
2. MICROSCOPIC
   - Proliferation of atypical lipoblasts resembling immature fetal adipocytes
   - Pleomorphic cells, hyperchromatic and pleomorphic nuclei, mitotic figures
   - Lipoblast: cytoplasmic lipid vacuoles that scallop the nucleus

Question 5

Desc the clinical manifestations/ complications of lipoma and liposarcoma

Answer 5

LIPOMA

1. CLINICAL MANIFESTATIONS
   - lump in the subcutaneous tissue which usually is well circumscribed, mobile, soft, solitary and painless.
   - Uncommon if the lump is large, intramuscular, poorly circumscribed.
   - The common sites are proximal extremities and trunk such as neck, back and shoulder
2. COMPLICATIONS
   - Rarely ever transforms into liposarcoma

LIPOSARCOMA

1. CLINICAL MANIFESTATION
   - Depends on the location
   - Lump/mass, can be slow or fast growing, generally painless
   - The common sites are deep tissues of lower extremities such as intermuscular regions in the thigh, buttocks and retroperitoneum
2. COMPLICATIONS
   - Frequently recur locally when not adequately excise and depend on the histological type

Question 6

Desc the morphology of rhabdomyosarcoma.

Answer 6

1. MACROSCOPIC
   - Firm, nodular, yellowish- white areas
   - Foci with gelatinous consistency, cyst formation
   - Areas of necrosis and haemorrhage
2. MICROSCOPING
   - Densely packed, primitive, small, round to oval cells with hyperchromatic nuclei and scant cytoplasm.
   - Rhabdomyoblast is the diagnostic cell
   - Round or elongated with granular, stringy, eosinophilic cytoplasm
   - Rich in thick and thin filaments

Question 7

Desc the clinical manifestations/ complications of rhabdomyosarcoma.

Answer 7

CLINICAL MANIFESTATIONS

• Rhabdomyosarcoma occur in childhood and adolesence (<20 yo)
• Often arise in the head and neck and genitourinary tract location that do not normally contain much skeletal muscle
• Swollen eye, nose bleed/ blocked/ discharge, abdominal discomfort, constipation, haematuria, per vaginal bleed
• Aggressive

COMPLICATIONS
- Metastasises via haematogenous route

Question 8

How to treat rhabdomyosarcoma?

Answer 8

Through surgery and chemotherapy @ radiotherapy

Question 9

Difference between benign and malignant.

Answer 9

BENIGN

• superficial tumour
• small tumour
• less vascularised
• Fixed tumour
• Not active

MALIGNANT

• deep seated lesions
• Large tumour
• More vascularised
• Mobile tumour
• Active