24-year-old (male) with genital warts

00:03 A 24 year old sexually active male complains of painless warts on his penis.

00:10 He is worried that he may have transmitted them to his girlfriend.

00:13 Biopsy of the lesions shows cells with perinuclear cytoplasmic vacuolization and nuclear enlargement.

00:21 The doctor treats the patient by chemically ablating the warts with 1% acetic acid solution.

00:26 The patient encourages his girlfriend to get tested too and he is worried that she may get an increased risk of developing malignancy if she has contracted the condition.

00:38 What cancer is this patient worried about? Answer choice (A) - kaposi sarcoma Answer choice (B) - burkitt lymphoma Answer choice (C) - hairy cell leukemia Answer choice (D) - hepatocellular carcinoma and answer choice (E) - cervical carcinoma Now take a moment to come to the answer alone before we go through it together.

01:02 Now let's go through the question together.

01:04 Now this is a microbiology question.

01:06 For even though we're showing a pathological lesion, we need to know how the underlying pathophysiology and the microbiology works to identify the organism at play and what cancer risk that organism induces.

01:21 Now this is a 2-step question.

01:22 The first step is to diagnose the cause of the warts and then we have to determine what type of cancer is associated with these warts.

01:30 And of course the stem is required as it provides significant clinical information and image and the type of question that we need to pursue.

01:39 So let's walk through this question together.

01:42 Step 1- we need to determine the diagnosis and the cause of the warts.

01:46 Now this patient has what is called genital warts which is also named 'condylomata accuminata'.

01:53 Now genital warts are caused by human papillomavirus or HPV.

01:58 Now human papillomavirus is the most common sexually transmitted infection.

02:02 Now that we know the patient has genital warts and is caused by HPV, we have step 2 of this question which is determining what type of cancer is associated with HPV infections.

02:14 Now the serotypes 6 and 11 of HPV are related to approximately 90% of genital warts.

02:22 Now, HPV infection increases the risk of cervical cancer and cancers of the vulva, vagina, penis and anus.

02:31 Now let's refer to our image where we can see how cervical cancer can be related and caused by HPV.

02:40 We'll start with the image of the cervix shown there and also shown the uterus and those green little dots we have the infection caused by human papillomavirus.

02:51 And then we zoomed in to actually look at the basal cell in the cell layers within the actual cervix itself and we see that we have infection of the basal cells.

03:00 And then weeks later, we have HPV in the epithelial cells actually inside and we even have viral replication.

03:08 Now thankfully, 90% of people will self heal without intervention within 2 years.

03:15 Now looking several decades into the future, what we can have happened is about 0.8 percent of people exposed to human papillomavirus will have developed cancer and it will be invasive as we can see as it goes through the basal cell layer and can develop cervical cancer as in this case.

03:34 So the answer to this question then is answer choice (E) - cervical carcinoma.

03:40 Now let's go through some of the other answer choices to discuss what are the microbiology associated wth the other type of cancers that we see listed.

03:50 Now answer choice (A) shows kaposi sarcoma which is associated with human herpes virus 8.

03:56 Answer choice (B) which is Burkitt lymphoma is associated with Epstein-Barr virus Answer choice (C) hairy cell leukemia is associated with human T-lymphotropic virus type 1.

04:10 And answer choice (D) which is hepatocellular carcinoma is associated with hepatitis B and C viruses.

04:18 Each of these is extremely high-yield to know essentially fundamental basic microbiology knowledge that we should have available on our memory at a drop of a hat for either examination of USMLE step 1 or upon questioning during the wards.

04:33 So in this case, the answer is again (E) - cervical carcinoma.

04:38 Now let's go over some high-yield facts regarding genital warts and HPV.

04:43 Now genital warts, which is also called condyloma accuminata is when you will see on a patient as we do on the image, small bumps or groups of bumps in the genital area and this can be associated with pain, discomfort or itching.

04:58 As we see in the image, this is the ventral aspect of the penis and we have these lesions right at the junction of the glans and the- shaft of the penis and several small lesions in the ventral aspect of the shaft itself.

05:13 Now these lesions can be small or large, they can be flat or they can be raised.

05:18 But most commonly they do look like cauliflower, very important for your board exams to keep this image in mind in case you see it again.

05:26 And very important to note that genital warts can affect both men and women.

05:32 Now almost all cases of genital warts are caused by human papillomavirus serotype 6 and 11.

05:38 Now speaking of human papillomavirus, HPV is the most common sexually transmitted infection with 79 million Americans, most in their late teens and early 20s infected with HPV.

05:51 It is transmitted through intimate skin-to-skin contact, generally through vaginal or anal sex and can be transmitted by a person even if they are asymptomatic and thus they are still cariers of the virus.

06:03 Now HPV infects the basal layer of the skin and mucus membranes with viral replication occuring following the latent period leading the hyperkeratosis and wart formation, very high-yield to know that basal layer of skin and mucus membranes.

06:18 Now very very important to know - there are more than 70 serotypes of human papillomavirus, the HPV serotypes 6 and 11 are related to approximately 90 cases of condyloma accuminata or genital warts.

06:32 Now, these two subtypes 6 and 11 have a very low neoplastic potential as we saw in our image that there's a 0.8 percent risk of developing cancer.

06:43 Now the other two serotypes that you need to know which are high-yield that actually have a much higher pre-neoplastic potential are serotypes 16 and 18 that are also seen in papillomavirus.