A 9-year-old boy presents with the above lesions on his trunk after returning home from a onemonth-long summer camp. Which of the following might be seen under light microscopy if a
biopsy is taken of one of the lesions?
- A) Multinucleated T lymphocytes
- B) Intranuclear inclusions
- C) Large intracytoplasmic, basophilic inclusions
- D) Small- or medium-sized lymphocytes with cerebriform nuclei
0 voters
EXP:
This patient has molloscum cantagiosum (MC) caused by poxvirus.
Molloscum contagiosum1, 2
• Presents usually as shiny, dome-shaped, peach-colored papules, with a central umbilication.
• Normally presents in children.
• Transmission classically associated with sharing towels (e.g., at public swimming pools) and
exposure to contaminated fomites (inanimate objects).
• Lesions appear 2-6 weeks after viral exposure and disappear on their own over the course of
months to a few years, with an average duration of about one year.
Biopsy of lesions shows Molloscum bodies, which are large, intracytoplasmic, basophilic
inclusions within keratinocytes.3, 4
Sounds pedantic, but Molloscum bodies are HY on the USMLE.
“Multinucleated T lymphocytes” refers to Warthin-Finkeldey cells, which can be harvested from
the tonsils of patients in the prodromal stage of measles.5
“Intranuclear inclusions” refers to Cowdry bodies, which are associated with herpesviridae
infections.6
“Small- or medium-sized lymphocytes with cerebriform nuclei” refers to mycosis fungoides and
Sezary syndrome, which are cutaneous T-cell lymphoma and leukemia, respectively. These
conditions are associated with human T-cell lymphotropic virus (HTLV).