title: Proliferating trichilemmal tumors: CT and MR imaging findings in two cases, one with malignant transformation.
abstract: We report the imaging findings in two patients with proliferating trichilemmal tumors. In the first patient, the tumor arose on the lower lip, a very unusual location for this type of tumor, and showed malignant transformation with metastasis to a regional lymph node. It was seen as a poorly marginated soft-tissue mass with isointense signal on T1-weighted MR images and hyperintense signal on T2-weighted images. Large areas of high signal intensity caused by necrosis were also found within the tumor on T2-weighted images. After i.v. administration of contrast material, the mass showed significant enhancement, with considerable portions remaining unenhanced. In the second patient, the tumor originated from a preexisting trichilemmal cyst and occurred in the hair-bearing area of the posterior part of the neck. CT scans showed a well-encapsulated cystic mass that contained multiple speckled calcifications in a wall of variable thickness. There were several foci of smooth soft-tissue elevations from the inner wall of the mass, which corresponded histologically to proliferating portions of trichilemmal cyst.
authors.affiliation: Department of Radiology, Inha University Hospital, Inchon, South Korea.
authors.forename: H J
authors.initials: HJ
authors.lastname: Kim
authors.forename: T S
authors.initials: TS
authors.lastname: Kim
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
authors.forename: Y M
authors.initials: YM
authors.lastname: Kim
authors.forename: C H
authors.initials: CH
authors.lastname: Suh
mesh_terms: D000368:Aged; D002471:Cell Transformation, Neoplastic; D005260:Female; D018859:Hair Follicle; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008046:Lip; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000473:pathology; D018295:Neoplasms, Basal Cell / Q000175:diagnosis* / Q000473:pathology; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology; D014057:Tomography, X-Ray Computed