Self-assessment questions and answers

Questions Question 1

Question 2

An irregular firm pale mass 4 x 3 x 2 em was removed from the upper back of an 80-year-old woman, because of discomfort and pain. Figures 1A and 1B show low and high power areas of the lesion, What is the diagnosis? What special staints) would confirm the diagnosis? How will the lesion behave and what is the prognosis?

A 72-year-old lady presented with a tender fibrous mass over the calcaneum. A hard gelatinous grey mass (2.5 x 1.3 x 1 em) with overlying skin was submitted for histology. Figures 2A, 2B and 2C show low, medium and high power views of representative parts of the lesion. What is the diagnosis? How would you confirm the diagnosis? What is the prognosis?

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186 CURRENT DIAGNOSTIC PATHOLOGY

Fig.2C

Answers Answer 1

Answer 2

Elastofibroma (dorsi). The figures show a tumour composed of dense collagen with intervening collections of mature adipose tissue. Within the collagen are numerous small clumps of brightly eosinophilic material (elastic) which are confirmed on an elastic stain (Fig. IC). The special stain shows the characteristic linear arrays of globular elastin and larger elastic fibres with a dense core. This uncommon condition, first recognised in 1959, usually involves the subcapsular tissue in the elderly more commonly in women. It may be bilateral and in some cases has been associated with hard manual labour. It is thought to be a degenerative condition due to local friction and probably results from abnormal elastogenesis rather than breakdown of existing elastic fibres. A genetic prediposition or enzymatic defect has been proposed but' not yet proven. It is benign with no propensity to recur. It is best treated by local excision although success has also been reported with radiotherapy.

Epithelioid sarcoma. Nodules showing proliferating epithelioid cells are present, some showing central necrosis and a surrounding zone of chronic inflammatory cells. There is considerable fibrosis around the nodules and hyaline collagen between tumour cells, which are seen in small cords and individually as well as forming nodules. Immunocytochemistry showed widespread positive staining for EMA (Fig. 2D), CAM 5.2 (Fig. 2E), Vimentin (Fig. 2F) and focal actin positivity. S 100 was negative. This tumour is commoner in a younger age group and in males and the commonest site is on the hand. Complete excision can be difficult to achieve. Prognosis which depends on size and depth of the tumour as well as the presence of necrosis, mitotic count and vascular invasion, is generally poor with multiple local recurrences and metastatic spread. Tumours on the extremities have a better prognosis than those occurring more centrally. The origin of this tumour remains unknown although the evidence to date favours origin from synovioblastic mesenchyme. , "

Fig.1C

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SELF-ASSESSMENT QUESTIONS AND ANSWERS

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Fig.2E

Fig.2F

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