1. A 15 year old male presents to the emergency room obtunded after ingestion of an unknown toxic substance. 12 hours after admission, the patient develops large, peripherally erythematous edematous plaques with central necrosis. The patient is in renal failure. A biopsy of the lesion is performed and examined under polarized light microscopy.

2. Excisional biopsy of a solitary asymptomatic reddish-brown nodule on the cheek of a 3 year old male

3. A 50 year old male presents with a slowly growing firm nodule on the nape of the neck. He denies any other medical conditions. An incisional biopsy is performed. Your diagnosis is:

4. A 31 year old African American female presents with a 1 year history of gradually worsening alopecia on the vertex of the scalp. She also complains of painful lesions that wax and wanes in her left ear.

5. 79 year old male presents to his clinician with complaint of a persistent slow-growing non-painful nodule on his scalp for 1 year. Primary excision is performed. The preclinical diagnosis is squamous cell carcinoma. Immunohistochemical markers including S100, MART1, AE1/AE3, and SMA, but is positive for Vimentin, CD99 and CD68.

6. A 68 year old male presents with a 6 month history of whelps with blisters occurring over the chest, back and scalp.

7. A 52 year old female with a long-standing history of cutaneous T cell lymphoma presents with a new lesion on the scalp. The lesion consists of a non-scarring well demarcated nummular patch of alopecia. There is slight erythema, but no scaling or induration. A biopsy is performed with a pre-operative diagnosis of mycosis fungoides.

8. A 35 year old southeast asian female presents to the dermatologist with a complaint of worsening hyperpigmentation bilaterally over the zygomatic arches. She states that the patches have been worsening over the last 5 years. She states that she has been utilizing an over-the-counter bleaching cream purchased in India for the last 4 years, but the lesions have only worsened. Your diagnosis is:

9. A 26 year old female presents with an asymptomatic firm well demarcated nodule on the lower extremity. The lesion is 1 cm in diameter, hyperpigmented without scale. An excisional biopsy is performed. The diagnosis is:

10. A 47 year old male presents to clinic with complain of a slowly progressive scaling rash over his right chest and back. The lesion consists of a sharply demarcated, scaling, erythematous and hyperpigmented plaque with distinct dermal induration. Routine H & E sections reveal the following:

11. A 65 year old female with a history of multiple myeloma presents with nodular, verruciform plaques on the face and extremities. Her history is complicated by renal failure. An excisional biopsy is performed.

12. A 5 year old female presents with a solitary lesion on the right hand. The lesion consists of multiple papules, arranged in a circular pattern over the dorsa of the hand. There is no scaling, erythema, or atrophy. The child is otherwise healthy.

13. An 85 year old male presents to clinic with the complaint of pruritic, blistering lesions over the left buttock and natal cleft. The patient states that the lesions begin as raised “whelps” which then blister then ulcerate. A punch biopsy is performed.

14. 32 year old male with a 2 year history of itchy, scaling plaques over the central back and scalp. A PAS stain for fungal organisms is negative.

15. A 42 year old male presents with a painful, erythematous to violaceous nodule on the lower extremity. The lesion measures 0.7 cm and blanches with pressure. An excisional biopsy is performed. The diagnosis is: