Slide 27. Squamous cell carcinoma, Skin

A. Brief Descriptions

  1. Most often occurs on sun-exposed skin.

  2. Risk factors: sunlight, industrial carcinogen(tars and oils),chronic ulcers and draining osteomyelitis ,old burn scars, ingestion of arsenicals, ionizing radiation, and (in the oral cavity) tobacco and betel nut chewing.

B. Gross Findings

      A shallow ulcer surrounded by a wide, elevated indurated border, occasionally raised, fungoid, verrucous lesions without ulceration.

C. Micro Findings

  1. Irregular masses of epithelial cells proliferate downward into the dermis.

  2. Individual tumor masses composed in varying proportion of normal or atypical squamous cells.

  3. Atypia: varying size & shape, hyperplasia, hyperchromatism, absence of intercellular bridge, presence of atypical mitosis & dyskeratotic cells.

  4. Dyskeratotic cells: individual cell keratinization with large, round & deep  eosinophilic cytoplasm & hyperchromatic nuclei.

  5. Well differentiated cells with intercellular bridge & keratin pearl formation & sheets of partially keratinized cells.

  6. Keratin pearl: a rounded nest of squamous epithelium in which the cells are arranged in concentric circles surrounding a central focus of acellular keratin.

D. Others:


E. Reference

     Robbins Pathologic Basis of Disease, 6th ed.  P.1184-1186.



Fig. 27-1 (1X).Cancer cells infiltrate from surface down into subcutis in the low power field.




Fig. 27-2 (4X).Cancer nests are seen in dermis.




Fig. 27-3 (2X)Cancer nests are seen in dermis.







Fig. 27-4 (4X)Cancer nests are seen in subcutis.




Fig. 27-5 (4X)Cancer cells with tendency to keratinization.




Fig. 27-6 (10X)Keratinizing cancer nests seen in superficial dermis.







Fig. 27-7 (20X)Squamoid cancer cells with keratinization and tendency to keratin pearl formation.







Fig. 27-8 (20X)Keratin pearl formation is seen above.




Fig. 27-9 (20X)Nest of hyperchromatic cancer cells with high nuclear and cytoplasmic ratio.




Fig. 27-10 (20X)Keratin pearl formation is seen in left lower field.










Fig. 27-11 (40X)Keratin pearl seen in this high power field.