Page 881 - Textbook of Pathology, 6th Edition

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Figure 29.5 Malignant fibrous histiocytoma. The tumour shows admixture of spindle-shaped pleomorphic cells forming storiform (cart-wheel)
pattern and histiocyte-like round to oval cells. Bizarre pleomorphic multinucleate tumour giant cells and some mononuclear inflammatory cells are
also present.

such as of the retroperitoneum have poorer prognosis than sites are the subcutaneous tissues in the neck, back and
those small in size and located superficially which come to shoulder (Fig. 29.6,A). A lipoma rarely ever transforms into
attention earlier. Metastases are frequent, most often to the liposarcoma.
lungs and regional lymph nodes. Five-year survival rate is
approximately 30-50%. Grossly, a subcutaneous lipoma is usually small, round CHAPTER 29
to oval and encapsulated mass. The cut surface is soft,
TUMOURS OF ADIPOSE TISSUE lobulated, yellowish-orange and greasy (Fig. 29.6, B).
Histologically, the tumour is composed of lobules of
Lipomas and liposarcomas are the common examples of mature adipose cells separated by delicate fibrous septa.
benign and malignant tumours respectively of adipose tissue. A thin fibrous capsule surrounds the tumour (Fig. 29.7).
Uncommon varieties of adipose tissue tumours include
hibernoma, a benign tumour arising from brown fat, and A variety of admixture of lipoma with other tissue
lipoblastoma (foetal lipoma) resembling foetal fat and found components may be seen. These include: fibrolipoma
predominantly in children under 3 years of age. (admixture with fibrous tissue), angiolipoma (combination Soft Tissue Tumours
with proliferating blood vessels) and myelolipoma
LIPOMA (admixture with bone marrow elements as seen in adrenals).
Lipoma is the commonest soft tissue tumour. It appears as a Infrequently, benign lipoma may infiltrate the striated muscle
solitary, soft, movable and painless mass which may remain (infiltrating or intramuscular lipoma). Spindle cell lipoma
stationary or grow slowly. Lipomas occur most often in 4th and pleomorphic (atypical) lipoma are the other unusual
to 5th decades of life and are frequent in females. They may variants of lipoma. The latter type may be particularly
be found at different locations in the body but most common difficult to distinguish from well-differentiated liposarcoma.

Figure 29.6 Lipoma. A, Common clinical location. B, The cut surface
of the tumour is soft, lobulated, yellowish and greasy.