Practice question answers, skin tumors 2
Practice
question answers, skin tumors 2
© Jun Wang, MD, PhD
1. A. Dysplasia limited to basal layer is most
consistent with actinic keratosis. Basal cell carcinoma has irregular budding, nest, cords of basaloid cells with scant
cytoplasm with peripheral palisading. Bowen
disease has full thickness dysplasia. Dermatophytosis
is fungal infection and has intraepidermal neutrophilic infiltration but not
keratinocytic atypia. Melanoma in situ has Pagetoid
spread of atypical melanocytes.
2. E. Actinic keratosis is a squamous precancerous lesion and may develop into squamous
cell carcinoma or basal
cell carcinoma.
3. E. This lesion has irregular nest, cords of
basaloid cells with scant cytoplasm with peripheral palisading, characteristic
for basal
cell carcinoma. The most important carcinogenic factor for melanoma, squamous
cell carcinoma or basal
cell carcinoma is UV light from sun exposure. Abnormal keratinocytic
turnover is seen various lesions, including psoriasis.
Chronic irritation, HPV may be associated with a small portion of these tumors.
Insulin
resistance is associated with dermatophytosis,
acanthosis nigricans, but not keratinocytic neoplasm.
4. B. This lesion has irregular nest, cords of
basaloid cells with scant cytoplasm with peripheral palisading, characteristic
for basal
cell carcinoma. Actinic keratosis has dysplasia limited to basal layer. Cylindroma
has compact nests of basaloid cell forming a jigsaw puzzle pattern separated by
thick basement membrane. Psoriasis
has elongated rete ridges without dysplasia or invasion. Tricholemmoma
has lobular or plate-like growth of pale pink, glassy cells with palisading at
periphery.
5. C. This lesion has irregular cords of basaloid
cells in a fibrotic background, characteristic for morphea form basal
cell carcinoma, and likely to have perineural invasion. Basal cell carcinoma rarely metastasize. Multifocality is seen in superficial type basal
cell carcinoma. Primitive hair follicles are seen in trichoepithelioma. Squamous pearls are commonly seen in well differentiated squamous
cell carcinoma.
6. C. Any invasive carcinoma at sensitive locations
such as face need Mohs surgery, especially morphea form basal
cell carcinoma.
7. B. This lesion has irregular cords of basaloid
cells in a fibrotic background, characteristic for morpheaform basal
cell carcinoma. Actinic keratosis has dysplasia limited to basal layer. Cylindroma
has compact nests of basaloid cell forming a jigsaw puzzle pattern separated by
thick basement membrane. Syringoma
has benign small tadpole shaped glandular proliferation in a fibrotic
background. Tricholemmoma
has lobular or plate-like growth of pale pink, glassy cells with palisading at
periphery.
8. B. This lesion has irregular budding of basaloid
cells from basal layer, characteristic for superficial type basal
cell carcinoma, and likely to be multifocal. Also see discussion of
question 5.
9. B. See discussion of questions 7 and 8.
10. This lesion has irregular nests of basaloid cells
in dermis, characteristic for basal
cell carcinoma, commonly associated with PTCH mutation. Beta-catenin
mutation can be seen in ovarian endometrioid adenocarcinoma, stomach cancer,
colon adenoma,
solid-pseudopapillary neoplasm and pilomatricoma.
BRAF mutation can be seen in various disorders, including melanocytic nevus and melanoma.
CYLD mutation is seen familial form cylindromas
(turban tumor syndrome, Brooke-Spiegler syndrome). MSH2 is a DNA mismatch
repair gene and its mutation is seen in colon cancer,
Lynch syndrome
and its variant Muir-Torre syndrome, etc.
11. D. This lesion has poorly differentiated small
cells that are positive for cytokeratin and neuroendocrine marker CD56. Without
molding and crush nuclear features, this is more likely to be Merkel cell carcinoma, that is commonly positive for CK20, but negative for
CK7. CD3 is a T cell marker and CD20 is a B cell marker. Desmin is muscular
marker. None of these three is positive for Merkel cell carcinoma, and usually muscular and lymphoid tumors are
negative for cytokeratin.
12. D. Skin tumor with poorly differentiated small
cells that are positive for cytokeratin and neuroendocrine marker CD56, without
molding and crush nuclear features, is more likely to be Merkel cell carcinoma. Basal cell carcinoma has irregular budding, nest, cords of basaloid cells with scant
cytoplasm with peripheral palisading, but not sheets of poorly differentiated
cells. Cylindroma
has compact nests of basaloid cell forming a jigsaw puzzle pattern separated by
thick basement membrane. Diffuse
large B cell lymphoma has large atypical cells that are positive for CD45
but negative for cytokeratin. Eccrine poroma
has well demarcated skin growth of small keratinocytes connecting to epidermis.
13. C. Full thickness epidermal dysplasia without
dermal invasion is consistent with Bowen
disease. Actinic keratosis has dysplasia limited to basal layer. Basal cell carcinoma has irregular budding, nest, cords of basaloid cells with scant cytoplasm
with peripheral palisading. Squamous cell carcinoma has intradermal irregular nests or cords of atypical
squamous cells with intercellular bridges and/or keratin pearl formation. Melanoma in situ has Pagetoid
spread of atypical melanocytes.
14. E. Intradermal irregular nests or cords of
atypical squamous cells with intercellular bridges and/or keratin pearl formation is consistent with squamous cell carcinoma. The most important carcinogenic factor for melanoma, squamous
cell carcinoma or basal
cell carcinoma is UV light from sun exposure. Cigarette smoking and HPV may
be associated with a small portion of these tumors. Molluscum contagiosum virus
is associated with molluscum
contagiosum. Polyvinyl chloride is associated with angiosarcoma
of liver.
15. D. Intradermal irregular nests or cords of
atypical squamous cells with intercellular bridges and/or keratin pearl formation is consistent with squamous cell carcinoma. Actinic keratosis has dysplasia limited to basal layer. Bowen
disease has full thickness epidermal dysplasia. Epidermal cyst
has greasy contents and lined by epidermis with granular layer. Tricholemmoma
has lobular or plate-like growth of pale pink, glassy cells with palisading at
periphery.
16. A. This lesion is characterized by large CD3
positive T cells in epidermis, a features highly suggestive of mycosis
fungoides, usually with marked elevated CD4/CD8 ratio. Pair of CD5 and CD23
are used to differentiate mantle
cell lymphoma from small
lymphocytic lymphoma, both are CD20 positive B cell lymphoma. CD15 and CD30
are usually positive in Hodgkin
lymphoma, characterized by Reed-Sternberg
cells. CK7 and CAM5.2 may be positive for Paget disease of breast,
genital
area, or other locations. HMB45 and S100 are positive for melanoma.
17. C. Atypical CD4 positive T cell infiltration in
epidermis is most consistent with mycosis
fungoides. Dermatophytosis
is fungal infection and has intraepidermal neutrophilic infiltration and mixed
lymphocytic infiltrate. Lichen planus has band like dense mixed normal
appearing lymphocytic infiltrate at dermal epidermal junction. Psoriasis
has elongated rete ridges without dysplasia or invasion. Sezary
syndrome has erythroderma, lymphadenopathy and Sezary
cells in peripheral blood and lymph nodes.
18. D. See discussion of question 17. Mycosis
fungoides has four different stages. This is likely tumoral stage due to
tumor formation. Bowen
disease has full thickness epidermal dysplasia.
19. A. Erythroderma, lymphadenopathy and Sezary
cells in peripheral blood and lymph nodes are consistent with Sezary
syndrome, and the tumor cells are CD4 positive T cells that also express T
cell marker CD3. CD11c is positive for hairy
cell leukemia. CD20 is a pan B cell marker. CD30 is positive for Hodgkin
lymphoma and anaplastic
large cell lymphoma, Reed-Sternberg
cells are seen in former and markedly
atypical lymphocytes are seen in the later. CD138 is a plasma cell marker
that is positive in multiple
myeloma, plasmacytoma,
lymphoplasmacytic
lymphoma, etc.
20. E. Erythroderma, lymphadenopathy and Sezary
cells in peripheral blood and lymph nodes are consistent with Sezary
syndrome. Chronic
lymphocytic leukemia and chronic
myeloid leukemia usually have markedly elevated white cell count with
circulating small lymphocytes with soccer ball appearance or less mature
myeloid cells. Hairy
cell leukemia usually has pancytopenia and circulating B lymphocytes with round nuclei and
fine hairy
projections.
Back to practice questions, skin tumor 2
Back to skin
tumors
Back to contents
Comments
Post a Comment