Pathology-Derm II Flashcards
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?
Malignant melanoma
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.