Cardiac and vascular tumors: Pathology review

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Case Study0:00–1:00

Two people came to the clinic one day. Kara is a 66 year old woman who came to the clinic after noticing gradually developing left arm swelling and redness over the past 3 months.
Physical examination reveals a tender purplish lesion along the left armpit. She has a history of hypertension, diabetes, and breast cancer that was treated 10 years ago with a modified radical mastectomy and radiation therapy.
Klay is a healthy 1 year old infant brought by his parents due to a rapidly growing “red bump” on his face. He has no history of trauma, and the lesion didn’t appear elsewhere.
Physical examination reveals a raised, bright red nodule on the left side of his face and no other abnormal findings. Now, both Kara and Klay have vascular tumors.
There are many types so it’s best to classify them into benign and malignant tumors. Starting with the most common benign vascular tumor in children; the strawberry hemangioma, where Hemangioma means a benign tumor of the blood vessels.

Strawberry Hemangioma1:00–1:48

A strawberry hemangioma appears as a superficial, bright red skin lesion that looks kind of like a strawberry, and they commonly affects the face.
Histologically, these lesions are confined to the epidermis. Now a typical strawberry hemangioma develops in infancy and grows pretty fast, but fortunately, it goes away on its own by 5 to 10 years of age.
So in terms of management, exams like to bring up a very concerned parent, but the correct answer will almost always be to reassure the parent that the lesion will regress without treatment.
Now, a related disorder is cherry hemangioma, which is the most common benign vascular tumor in adults. This tumor appears dark red, like a cherry.

Cherry Hemangioma1:48–2:17

Histologically, this lesion extends to the superficial papillary dermis, so they reach much deeper than strawberry hemangiomas.
These tumors increases in frequency with age, and unlike strawberry hemangiomas, they do not regress spontaneously. Cavernous hemangiomas are soft, bluish lesions, and unlike strawberry and cherry hemangiomas, these are usually seated in the deep dermis.

Cavernous Hemangioma2:17–3:05

The word “cavernous” means cavern-like. So it’s not surprising that histologically, these appear as large, endothelium-lined spaces filled with red blood cells.
Cavernous hemangiomas can also be located in organs like the liver, spleen or even the brain. Also, Von-Hippel Lindau syndrome is an autosomal dominant condition that causes numerous tumors and cysts throughout the body, one of these being cavernous hemangiomas of the cerebellum and retina.
Look for a history of bilateral pheochromocytoma or renal cell carcinoma. The next tumor is cystic hygroma, or a cavernous lymphangioma.

Cavernous Lymphangioma3:05–3:34

It’s a benign tumor of the lymphatic vessels that typically arises in the neck, and is associated with both Down and Turner syndrome.
Histologically, this tumor is made of an endothelial lining, but the difference between it and hemangiomas is the absence of red blood cells, because lymphatic vessels have lymphatic fluid in them, not blood Next up we have pyogenic granuloma, which is the biggest misnomer in medicine.

Pyogenic Granuloma3:34–4:12

First, it does not produce pus, and histologically, it’s not a granuloma. Instead, this is a benign, polypoid or dome-shaped hemangioma that can ulcerate and bleed.
Histologically, the tumor shows lobules made of proliferating capillary and edema, which makes it look like granulation tissue.
Board exams will often give you risk factors, such as a history of trauma to the area, or pregnancy, especially in the first trimester.

Glomus Tumor4:12–4:54

Next are glomus tumors. These arise in the glomus bodies which are small arteriovenous shunts located in the dermis.
They help regulate body temperature by shunting blood away from the skin in cold temperatures, and to the skin when it’s hot.
A glomus tumor usually arise from the smooth muscle cells in the glomus bodies and they are painful, bluish-reddish tumors most commonly found under the fingernails.
An important differential diagnosis is subungual melanoma, which appears similarly, but the difference is the presence of melanin-pigmented cells on histology.
So it’s important to get a biopsy! The next two tumors are associated with HIV.

Bac. Angi. & Kaposi Sar.4:54–6:21

There’s bacillary angiomatosis, which is benign, and Kaposi sarcoma, which is malignant. Bacillary angiomatosis is technically not a tumor; it’s an infection caused by the gram negative bacillus, Bartonella henselae.
It’s thought that the bacteria enters the intravascular compartment, and releases angiogenic factors that stimulate benign endothelial cell proliferation.
Kaposi sarcoma on the other hand is a malignancy of the endothelial and smooth muscle cells caused by human herpesvirus 8, or HHV-8, or by HIV.
It’s still unknown exactly how these viruses cause malignancy. Now, both conditions appear as red-violet papules on the skin.
Kaposi sarcoma also tend to affect the buccal mucosa as well as the gastrointestinal and respiratory tracts. So beware for questions that pose Kaposi sarcoma as a case of GI bleeding or hemoptysis.
The best way to differentiate the two is microscopically. Bacillary angiomatosis shows gram negative bacilli using Warthin-Starry stain, as well as a neutrophilic infiltrate.
On the other hand, Kaposi sarcoma shows spindle shaped tumor cells along with a lymphocytic infiltrate. Okay, another malignant tumor of the blood vessels is angiosarcoma, which is a cancer of the endothelial lining of the blood vessels.

Angiosarcoma6:21–7:26

They are more common in older people and affects sun-exposed areas like the head,and neck. If the person has a history of radiation therapy, like for breast cancer, they can also develop.
A specific type is hepatic angiosarcoma which is linked to chronic exposure to arsenic in pesticides, polyvinyl chloride, or PVC, a plastic commonly used in industry, and thorotrast, an old contrast medium.
A helpful clue is that hepatic angiosarcoma cells express CD31, also called PECAM1, which is normally expressed on the surface of endothelial cells and acts as a binding point for leukocytes.
However, in angiosarcoma, CD31 promotes angiogenesis, which is how these tumors develop. This is a way your exams can connect this pathology with normal physiology.

Lymphangiosarcoma7:26–7:41

Lymphangiosarcoma is similar to angiosarcoma, except it involves the lymphatic vessels. The main risk factor is chronic lymphedema, which can arise after a mastectomy or lymph node dissection for breast cancer.

Cardiac Myxoma7:41–9:49

Alright now that we’ve looked at the vascular tumors, let’s shift gears and go over the cardiac tumors. The most common primary cardiac tumors in adults are myxomas.
Myxoma is derived from “myxoid” which means connective tissue. Therefore, myxomas are benign tumors derived from undifferentiated connective tissue cells in the heart.
A high yield fact is that most of them occur in the atria, especially the left atrium. The tumor obstructs blood flow through the mitral valve, causing a decrease in the left ventricular stroke volume.
Remember for your tests that a common presentation is multiple episodes of syncope. Other symptoms include shortness of breath on exertion and palpitations.
Atrial myxomas produce vascular endothelial growth factor or VEGF, which promotes angiogenesis, making the tumor friable and more likely to bleed.
Myxomas also make interleukin-6, a cytokine that leads to systemic symptoms like fever and weight loss. Exams can use this information to tie in concepts relating to immunology like the fact that interleukin-6 is also responsible for the production of acute-phase reactants such as CRP and fibrinogen.
So they could use a scenario of an atrial myxoma and ask: “ the cytokine produced by the pathology this individual has is also responsible for....” Auscultation of the heart apex shows the classic “tumor plop” sound during diastole.
Transesophageal echocardiography, or TEE confirms the diagnosis, revealing a pedunculated mobile mass in the atrium. The reason we go through the esophagus is because it’s directly posterior to the left atrium, providing us with a good view of the left atrial chamber.
Microscopically, scattered connective tissue cells are seen mixed with a gelatinous, mucopolysaccharide stroma. Okay, now the most common primary cardiac tumor in children is cardiac rhabdomyoma.

Cardiac rhabdomyoma9:49–10:29

Rhabdomyomas are hamartomatous growth of the cardiac muscle. “Hamartomatous” means benign hyperplastic growth, meaning there’s no neoplasia.
The vast majority of cardiac rhabdomyomas are associated with tuberous sclerosis, a genetic disorder that causes tumor formation in various other organs like the brain, eyes, and lungs, liver, and kidneys.
A big clue is adenoma sebaceous which are flat, reddish lesions on the skin that resemble freckles. Okay, to review.

Review10:29–11:48

Vascular tumors are benign or malignant. Benign tumors include strawberry hemangiomas, which appear in infants and go away spontaneously, and cherry angiomas , which appear in older people and do not regress spontaneously.
Cavernous hemangiomas are more deep-seated in the dermis, and can also involve internal organs like the brain. Cystic hygromas are lymphangiomas located in the neck, and are classically associated with Down and Turner syndrome.
Pyogenic granulomas are pedunculated, and are associated with trauma and pregnancy. Glomus tumors are benign tumors of the thermoregulatory glomus bodies, and are located underneath the fingernails.
Bacillary angiomatosis is caused by Bartonella henselae, while Kaposi sarcoma is caused by HHV-8, and both are associated with HIV.
Hepatic angiosarcoma is associated with exposure to arsenic, PVC or thorotrast. Lymphangiosarcoma is associated with chronic lymphedema, such as after a radical mastectomy.
Cardiac tumors include atrial myxoma which is the most common in adults, and rhabdomyoma, which is the most common in children.
Alright, back to our cases. Considering the appearance and location of Kara’s lesions, it’s likely that she has lymphangiosarcoma, which is caused by her previous modified radical mastectomy.

Summary11:48–12:09

Next due to her young age and the appearance of the tumor, Klay likely has a strawberry hemangioma, and his parents were reassured that the lesion usually goes away on its own.
Cardiac and vascular tumors: Video and Causes | Osmosis