A 25 year old female presents with a small papule on her leg. It has been present for 2 years and is asymptomatic besides the fact that is bleeds when shaving. What do you rule out first if you want to clear her mind that she doesn't have the worst possible case?
A patient comes to see you with small papule on her leg. You get this image from the lab. Based on the pathology you see, what should the papule do when you squeeze it if it is not a nevi?
Dimple. It is a dermatofibroma. Note spindle cells (dermal fibroblasts surrounded by collagen), absence of a capsule, melanin aggregation, absence of mitosis and rete ridges extending into the dermis.
An elderly man presents with ulcerated papules on his neck and forehead that have grown slowly over two years. They are painless but bleed with slight trauma. Are you concerned about this metastasizing if it is a tumor?
No. This patient has basal cell carcinoma and they rarely metastasize. Note elevated lesion, central ulcerations, telangectasia, and pearly/waxy appearance.
How might a patient with the condition depicted in this slide present in clinic?
Waxy/pearly, pink, ulcerating nodule characteristic of basal cell carcinoma.
A 67 year old man comes to see you with a sore that does not heal on his hand. He worked as a construction worker and was in the sun for a number of years. If this could lead to squamous cell carcinoma, but is not, what is it?
Actinic keratosis. Note hyperkeratosis.
The lab sends you this after getting a biopsy from a patient. What is your diagnosis?
Squamous cell carcinoma. Note pink lesion from keratin production, keratin swirls and intercellular bridges.
How would someone come down with this? Why is this concerning to you?
Lots of UV radiation from sunlight on the lower lip. These types of squamous cell carcinomas have the highest rate of metastasis.
What non-UV-related conditions can cause squamous cell carcinoma?
Immunosuppressed patients (organ transplant patients, HIV patients etc.)
Why might this patient be excited when you give him the diagnosis? How would it look histologically.
It is a keratoacanthoma and these can regress without treatment. This is a well-differentiated squamous-cell carcinoma.
A patient comes to see you with an 18-month history of a pigmented lesion on his mid-back. His wife called this lesion to his attention because of its enlarging size and variation in color. What makes up the darker and lighter colors of this lesion?
Darker nodularity means that the melanoma has invaded deeper near blood and lymphatic vessels. This gives you a hint at the *Breslow level
How do you measure the Breslow level of a melanoma? What measurement makes you feel a little shaky about the lesion?
Find the highest point in the granular level and find the lowest point of invasion into the dermis. 1-2 mm is when you start to be concerned.
How do you know this is not basal cell carcinoma? How would you confirm your suspicions?
Invasion of single melanocytes into the epidermis. Basal cells invade in groups. This is melanoma. You can confirm your suspicion with HMB-45 and S-100 staining lights up melanocytes specifically.
Which of these are you more nervous about when you see the patient?
The nodular melanoma. This is because it has a vertical growth phase from the beginning. Lentigo maligna melanoma has a long radial growth phase where it stays superficial.
An adult comes to see you for blurred vision in one eye. You look into his eye and see this. Where is the dark spot originating from?
The choroid of the eye. This is the most common malignancy of the eye and is a melanoma.
How do you determine if this patient has a nevus or a dermatofibroma?
Squeezing it will not cause dimpling as in dermatofibroma. You could also do a biopsy and you would see nests of melanocytes that turn into cords as they go deeper and lose their pigmentation.
A 40 year old female with a firm nodule in the upper back. You do a biopsy of the nodule and see this. What is your biggest concern?
This is an epidermal inclusion cyst. Note that the upper portion of the nodule is filled with keratin. Your biggest worry is bursting of the cyst which is filled with strong inflammatory material.
What are epidermal inclusion cysts of the hair follicle called? Sebaceous glands?
Pilar cysts. Steatocystomas.
A 22 year old female soldier returned from a 3 month deployment with a new skin lesion. The lesion began as an itchy spot that gradually expanded. Application of Neosporin ointment was not helpful. The patient is otherwise well and not taking any medications. Why did Neosporin not help?
Dermatophytes are fungi that grow on dead skin, hair and nails. This is why neosporin did not work. Note the elevated scaly lesion with red borders due to immune reaction against fungus.
What is this often misdiagnosed as? If your attending doesn't believe you how could you convince him?
Psoriasis. But its actually tine corporis. Note the rounded reddish area with center scaling. Note hyperkeratosis (causing white scale), parakaratosis and epidermal hyperplasia (causing elevation of lesion). You could convince your attending with a silver stain or KOH treatment that is specific for fungi.
A 15 year old presents with a hyperkeratic, rough-surfaced, wart-like growth on hands and feet. What causes these warts? What are the seeds in the wart?
HPV. The "seeds" are typical of warts and are thrombosed capillaries.
What is the main thing you don't want to miss in this patient with HPV? How do you confirm it is not the worst thing?
Squamous cell carcinoma. They often present as wart-like lesions. Note hyperkeratosis, acanthosis, papillomatosis and downward extension of the rate ridges…confirming warts and not cancer.
A patient comes to see you with cervical cancer. You do a pap smear and get this. What do you see and what does it tell you?
Vacuolated cells point to early viral proliferation.
Who is at increased risk of getting warts?
Immunosuppressed patients…warts are viral and they are more susceptible.
What are the pigmentation and melanocyte disorders?
Think of when you get a sunburn your skin gets N FLMD because your melanocytes are mad. Nevi, Freckle, Lentigo, Melanoma, Dysplastic Nevi.
A patient comes to see you for a routine checkup with his wife. He says everything is good but she makes a comment about a lesion on his skin. He says it's just a freckle and she notes that it does not change color with sunlight. Is he right?
No. It is likely a lentigo if it looks like a freckle but does not respond to UV light.
A 64 year old man comes in to see you concerned about a number of moles he has on his back, trunk and buttock. You note that they all vary in size and color. After confirming a diagnosis with a biopsy, what is the best news he could hope for?
Dysplasic nevi. These tend to appear on sun-exposed and non-exposed areas. The biopsy would hopefully show non-uniform nests of melanocytes that have not penetrated deep into the dermis.
Two of your patients died this year of malignant melanoma. Genetic testing at the time of death for melanoma risk factors showed that patient A had a mutation in cell survival and patient B had a mutation in cell proliferation mechanisms. What were likely mutations in these patients?
Patient A probably has a mutation in p14, which normally enhances p53 function by inhibiting MDM2 (a p53 inhibitor). Patient B probably has a mutation in p16, which normally enhances CDKIs of CDK 4 and 6.
A patient with malignant melanoma has genetic testing and is found to have normal apoptosis and senescence machinery. What mechanisms upstream from this machinery could still cause melanoma?
RAS, PI-3K and BRAF mutations
What are the different benign epithelial skin tumors?
"A SAFE way to get skin cancer!" Acanthosis nigricans, Seborrheic Keratosis, Adnexal tumors, Fibroepithelial polyps, Epithelial cysts
A patient comes to see you with a crusting lesion with irregular borders and varying colors of brown. You do a biopsy looking for melanoma and see hyperkeratosis with horn cysts. What mutation likely caused this condition?
A patient comes to see you with velvety hyper pigmented lesions in the flexural areas of his body. Tissue sampling shows enlarged dermal papilla forming large peaks and valleys with no melanocyte hyperplasia. What other condition may this skin lesion be a marker of?
Why are eccrine and apocrine carcinomas often confused with metastatic adenocarcinomas?
They have a tendency to form glands with basaloid cells that look like adenocarcinomas.
What are the premalignant and malignant skin tumors?
Actinic keratosis, Squamous cell carcinoma and basal cell carcinoma
A patient with HIV comes to see you with a lesion on his ear. You note hyperkeratinization in your exam and after biopsy conclude the lesion is a squamous cell carcinoma. What are the likely mutations you will find if you examined the tumor cells?
p53 and RAS
After confirming a skin cancer in a patient's biopsy, you tell him it will be okay because these kinds of tumors rarely metastasize. What is the most likely mutation you would find if you analyzed the genetics of the tumor cells?
PTCH can no longer bind SHH (sonic hedgehog) or SMO. SMO then continues signaling of transcription factors that cause unregulated transcription.
A patient presents with a fleshy nodule that you biopsy and see storiform fibroblasts and the tumor invading the subcutaneous fat. How could you treat this tumor with medication?
Dermatofibrosarcoma Protuberans is a condition where PDGF-beta is over expressed and causes tumor growth. Inhibiting PDGF-beta receptors will slow tumor growth and are good medications.
A patient comes to see you with scaly red-brown patches and you are in a hurry so you give him some hydrocortisone and leave. He comes back a weak later with the lesions all over his body. Biopsy of a lesion shows CD4+ cell invasion just below the dermis. What was his condition at first and what has it progressed to now?
It started as mycoses fungoides and progressed to Sezary Syndrome.
A patient comes to see you with wheals on her skin that can be produced by simple touch of a pencil. What are you likely to see on a biopsy and what gene is likely mutated.
This is mastocytosis. You will see an accumulation of mast cells in the dermis. The mutation is C-KIT, a Tyr kinase receptor
What are the acute inflammatory dermatoses?
Uticaria, Acute Eczematous Dermatitis and Erythema Multiforme
What are the chronic inflammatory dermatoses?
Psoriasis, Seborrheic Dermatitis and Lichen Planus
When does cradle cap get bad?
It starts out as good ole cradle cap but progresses to parakaeratosis and neutrophil aggregation near hair follicles. Official name is seborrheic dermatitis.
A patient comes to see you with violaceous, itchy plaques and papules. You do a biopsy and note dense lymphocyte invasion of basal cells, zig-zag destruction of basal cells and hyperkeratosis. What condition might this patient have?
What are the bullous skin diseases?
Pemphigus, Bullous pemphigoid, Dermatitis Herpetiformis, Epidermolysis Bullosa and Porphyria.
What are you squeezing out of your nose when you get blackheads out?
Black keratin plug due to melanin. These are called open comedones.
What are the four things that contribute to acne development?
Keratin plug blocks sebum outflow, Sebaceous gland hypertrophy, Bacteria, and Follicle Inflammation
A patient presents with tender erythematous plaques on the lower legs. She has a fever and lesions that have been there for some time appear bruise-like. What are early and late symptoms of this condition caused by?
This is panniculitis which is an inflammatory reaction in the subcutaneous fat. Early on CT septa widen due to edema and fibrin exudate and neutrophils infiltrate. later on, lymphocytes, giant cells and eosinophils infiltrate with septal fibrosis.
A patient presents with firm, pruritic, pink umbilicated papules. On microscopic examination lesions show pink cytoplamsic granules in the stratum granulosum. What are these pink granules?
Molluscum bodies in the viral poxvirus-caused disease: molluscum contagiousum
A mother brings her child in with an erythematous macule surrounded by multiple pustules with honey-colored crusting. Histological analysis shows neutrophil aggregation beneath the stratum corneum. What is the agent causing these symptoms?
This is impetigo caused by Staph Aureus. It produces a toxin agains dsg1 which causes blistering in the epidermis.