Malignant tumours of the skin

1. Malignant tumours of the Skin
By
Dr.Varughese George
Department of Pathology
MGMCRI

2. Learning Objectives
At the end of this session, you should know about gross
and microscopical features of
• Basal Cell Carcinoma
• Squamous Cell Carcinoma
• Malignant Melanoma

3. Pre-malignant lesions of the skin
• Solar keratosis (actinic keratosis, senile keratosis)
• Bowen’s disease
• Xeroderma pigmentosum
• Erythroplasia of Queyrat

4. Malignant Conditions of the Skin
• Basal cell carcinoma or rodent ulcer is a locally invasive
slow growing tumour of the skin of face in the middle-
aged that rarely metastasises.
• Squamous cell (or epidermoid) carcinoma occurs most
commonly in the skin, oral cavity, oesophagus, uterine
cervix, penis and at the edge of chronic ulcers.
• Malignant melanoma or melanocarcinoma is the
malignant counterpart of naevus and is the most rapidly
spreading malignant tumour of the skin, mucosa and
other melanin containing sites.

5. Basal Cell Carcinoma
GROSS FEATURES
• Tumour is commonly a nodular
growth with central ulceration
(nodulo-ulcerative).
• Margins of the tumour are
pearly white and rolled while
the base shows ulceration.
• Tumour burrows into the
underlying tissues like a rodent
and destroys them.

6. Basal Cell Carcinoma
MICROSCOPIC FEATURES
• Tumour cells resemble normal
basal cell layer of the skin and
grow downwards from the
epidermis in a variety of
patterns—solid masses, nests,
islands, strands, keratotic
masses, adenoid, etc.
• Tumour cells forming the
periphery of tumour have
parallel alignment or show
palisading (basaloid cells).
The dermis is invaded by irregular masses
of basaloid cells with characteristic
peripheral palisaded appearance.

7. Basal Cell Carcinoma
MICROSCOPIC FEATURES
• Tumour cells are basophilic
with hyperchromatic nuclei.
• Stroma shrinks away from
epithelial tumour
nests,creating clefts which
help in differentiating it from
the adnexal tumours.
The dermis is invaded by irregular masses
of basaloid cells with characteristic
peripheral palisaded appearance.

8. Squamous Cell Carcinoma
GROSS FEATURES
• Tumour is either in the form of
nodular and ulcerative growth,
or fungating and polypoid mass
without ulceration.
• Margin of the growth is elevated
and indurated.
• Cut section of the growth shows
grey-white endophytic as well as
exophytic tumour The skin surface on the sole of
the foot shows a fungating and
ulcerated growth (arrow).

9. Squamous Cell Carcinoma
MICROSCOPIC FEATURES
• There is downward as well as
outwards proliferation of
squamous epithelium with
increased number of layers
which show loss of orderly
maturation.
• Masses of tumour cells invade
through the basement
membrane into subepithelium
or dermis.
The dermis is invaded by downward
proliferating epidermal masses
of cells which show atypical features.

10. Squamous Cell Carcinoma
MICROSCOPIC FEATURES
• In better-differentiated tumours,
the tumour cells are arranged in
concentric layers or whorls and
contain concentric layers of
keratin material in the centre of
the cell whorls.
• The tumour cells show variable
degree of differentiation and
anaplasia and accordingly
labelled as well-differentiated,
moderately-differentiated and
poorly-differentiated.
• The masses of tumour cells are
separated by lymphocytes
A few horn pearls with central laminated
keratin are present.

11. Squamous Cell Carcinoma
Histological Types
• Keratinizing squamous cell carcinoma
• Large cell non keratinizing cell carcinoma
• Small cell non keratinizing cell carcinoma
• Verrucous carcinoma

12. Malignant Melanoma
GROSS FEATURES
• May appear as flat,
macular or slightly
elevated, nodular lesion.
• The lesion exhibits
variation in pigmentation
appearing in shades of
black, brown, grey, blue
or red. The borders are
irregular
Malignant melanoma oral cavity. In this
hemimaxillectomy specimen, whitish
oral mucosa shows an elevated blackish
area with ulceration. Cut surface shows
blackish tumour with irregular outlines
(arrow).

13. Malignant Melanoma

14. Malignant Melanoma
MICROSCOPIC FEATURES
• The tumour has marked
junctional activity at the
epidermo-dermal junction and
grows horizontally as well as
downwards into the dermis.
• The invading tumour cells are
arranged in a variety of
patterns—solid masses, sheets,
islands, nests, etc.
There is marked junctional activity at the
dermal-epidermal junction.

15. Malignant Melanoma
MICROSCOPIC FEATURES
• Individual tumour cell contain
large vesicular nuclei with
peripherally condensed
chromatin and having
prominent eosinophilic nucleoli.
The cytoplasm is amphophilic.
• Melanin pigment is present in
the cytoplasm in the form of
uniform fine granules.
Tumour cells resembling epithelioid cells
with pleomorphic nuclei and prominent
nucleoli are seen as solid masses in the
dermis. Many of the tumour cells
contain fine granular melanin pigment..

16. Malignant Melanoma
Tumor cells with abundant melanin
pigment is seen in most of the areas.
Tumor metastasis in a deep inguinal
lymph node