Tumour Pathology Case 001

Q1. What is the organ?

the organ is SKIN

Q2. Describe the structure of the organ.

the skin is composed of two layers

1. the epidermis which is the outer most layer of cells which is bounded at its deep surface by the basement membrane. Sitting on this is a basal cell layer arranged vertically and a series of layers of cells which undergo increasing keratinization as they migrate to the surface. On the surface the cells have died and been almost completely replaced by keratin and lie horizontally like tiles. The cells in the epidermis are characterized by desmosomes that are intercellular bridges between adjacent cells, and function to tightly bind the epidermal cells together for maximal mechanical shear/wear properties and to exclude/retain moisture. This layer carries no blood vessels and no nerve endings. At some places the epidermis invaginated the dermis with specialized skin structures, such as hair follicles, sweat and apocrine glands. The pigmentation cells reside in the basal layer.
2. the dermis which is the deeper layer (below the epidermis' basement membrane) which contains support structures such as blood and nerve supply and epidermal invaginations such as hair follicles and sweat glands. It has a surrounding dense fibrotic stroma.

Q3. What is the pathological entity?

The slide shows a BASAL CELL CARCINOMA under the normal epidermis

Q4. Describe the pathological entity.

There is a non-ulcerating lesion separate to the overlying epidermis which has a palisading margin and is made of small, dark, monotonous cells without central organization. There is a peritumoral infiltrate of small inflammatory cells. The ulcer may have raised rolled edges and telangiectasia

Q5. Describe the natural history of this entity.

The BCC is also known as a "RODENT ULCER" because of its propensity to invade locally producing slowly enlarging ulcers. Cure is achieved by local control as the lesion rarely involved lymph nodes or produces secondaries. The lesions are typically found in the 'glasses band' - the band from eyebrow to columella and extending from ear to ear.

Q6. Describe the metastatic potential of this entity

Metastatic potential is small.

Q7. What are the genetic determinants of this entity

There is a familial syndrome of multiple BCCs called GORLIN syndrome (also known as "Nevoid Basal Cell Carcinoma Syndrome (NBCCS)". This is a defect in the patched gene which is a gene responsible for embryological formation. In Drosophila melanogaster (all of those who completed Secondary Science with the Harry Messel green Biology text will know about them … they are fruit fly!), the abnormalities of patched produce fused wings among other abnormalities. Interestingly Gorlin patients are known to suffer from FUSED RIBS - go figure! When Gorlin patients are treated with radiotherapy, they characteristically develop BCCs in the area just immediately lateral to the light field edge.

Q8. Discuss the prevention and treatment  of this entity