Immune Status, Strain Background, and Anatomic Site of Inoculation Affect Mouse Papillomavirus (MmuPV1) Induction of Exophytic Papillomas or Endophytic Trichoblastomas
Figure 2
A trichoblastoma from a 68 year-old Caucasian male showed a pseudo-encapsulated, multinodular, basaloid tumor with fibrocellular stroma spanning the reticular dermis extending into subcutaneous fat (A). No epidermal connection or retraction artifact was noted. Tumor lobules were arranged as monomorphous basaloid cells in a cribriform pattern with peripheral palisading some resembling abortive hair follicles (B, F). Focally, tumor lobules exhibited squamous eddies, papillary mesenchymal bodies, and a germinative component comprising basaloid cells admixed with distinct pales cells (Zellballen) (C–E, D is an enlargement of boxed area in C).
