Case Connections Flashcards
Histology of the epithelium
VS is a 47-year-old man with a recurrent epidermoid cyst (sebaceous cyst) on his upper back. Two months ago, he had the cyst incised and drained in another clinic after he had tried to squeeze out the contents a few months before that. “It just keeps coming back,” he says. “Now it’s so big, you can see it through my shirt.” On his back, you note a firm, mildly tender, smooth ovoid nodule within the skin. It is not fluctuant. “Can you remove it so this doesn’t keep happening?”
What will need to be done to achieve complete removal of the lesion?
- You explain that the cyst is caused by collection of sebum (skin oil) and cells within a sebaceous gland and that removal of the entire gland is necessary to avoid recurrence.
- Because a sebaceous gland is a multicellular structure, draining the contents would just leave an empty cavity; the holocrine secretion process would result in re-accumulation of material over time.
- You excise the glandular structure, including the epithelial lining, and assure VS that the cyst is gone for good.
Prokaryote Structure and the Gram Stain
On your first Friday night in a small hospital emergency department, you treat a student from the local college. KD has had a febrile illness for almost 2 days. “First I just felt tired and generally sick. Then the headache started, and now my neck hurts when I bend it.” You are already thinking about admission and treatment for possible meningitis, and you start all the usual measures—lab tests, IV fluids, lumbar puncture, and empiric antibiotics. You ask the head nurse how long it will take to get the Gram stain results on KD’s CSF. “Not until Monday, I think. It’s the weekend,” she replies. You type “how to do gram stain” into your favorite search engine.
How will you explain your need to have the Gram stain results sooner than later?
You know that you could just treat empirically, but it would certainly help target the treatment if you knew the likely cause of KD’s meningitis. You explain to the nurse, “Even before we can get a culture result, I may be able to identify the likely cause based on the Gram stain. I can select an antibiotic that will most directly target the specific bacteria I see. And if I don’t see anything at all, I’ll still treat with antibiotics, but I’ll also be thinking about a possible viral cause. In KD’s case, if I’m right about Neisseria meningitidis as the cause, I may see gram-negative, pink colored diplococci. Can you give me directions to the microbiology lab?”
