QUESTION 11-1. Which of the following regarding normal vessels is INCORRECT?
A) Endothelial cells express CD31, CD34, von Willebrand factor, and Ulex europaeus lectin-1.
B) Pericytes and smooth muscle cells express smooth muscle actin and α-smooth muscle actin.
C) Lymphatic endothelial cells express LYVE-1 and podoplanin (D2-40).
D) Endothelial cells play an important role in antigen presentation and cytokine secretion.
E) Both large arteries and veins contain a prominent internal elastic lamina that can be highlighted with an elastic stain.
QUESTION 11-2. Which of the following histopathologic features is NOT associated with vascular malignancy?
A) Small round vessels in a lobular distribution with flat endothelial cells containing inconspicuous nucleoli.
B) Prominent anastomosing angular vascular channels with plump endothelial cells containing conspicuous nucleoli.
C) Angular vessels lined by compact endothelial cells that exhibit multilayering or “piling up” on one another.
D) Solid areas composed of polygonal and/or spindled endothelial cells with intracytoplasmic lumina containing red blood cells
E) Irregular angulated vessels extending into the subcutis with intraluminal papillary growth and endothelial tufting.
QUESTION 11-3. You are covering for a fellow physician’s practice and as you are preparing to see a 3-year-old female patient for the first time, you notice in her chart that she presented at 12 months of age with a red to purplish rubbery nodule on the cheek that developed during her first weeks of life. The mother reported that the tumor evolved from a pink macule that gradually increased in size. The lesion was not ulcerated and did not interfere with any vital structures such as the eyes or airways. Your colleague reported in the chart that the lesion blanched with compression and no intervention was pursued. When you examine the child you notice that the lesion has now disappeared with only residual redundant skin. Although the lesion was not biopsied, the images below represent what the tumor would have looked like microscopically at 6 months (image A), 12 months (image B), and at its current state (image C). Which of the following statements regarding this tumor is INCORRECT?
A) These tumors are typified by a fairly predictable natural history in the great majority of cases, which includes rapid proliferation and enlargement in the first 8 to 12 months of life (the proliferative phase) and regression over a period of 1 to 5 years (the involutional phase).