Metastatic malignant proliferating trichilemmal tumor detected by positron emission tomography.
BACKGROUND
Whole-body 18F-fluorodeoxyglucose-positron emission tomography (18F-FDG-PET) was introduced in 1990s, and its efficacy for cerebral mapping and for selective detection of various malignancies is now being recognized.


OBJECTIVE
To report on the usefulness of whole-body 18F-FDG-PET for detecting a metastatic lesion in a rare case of malignant proliferating trichilemmal tumor.


METHODS
A malignant proliferating trichilemmal tumor on the occipital scalp of a 69-year-old female recurred on the margin of the surgical scar after an initial wide excision, and it was removed by Mohs micrographic surgery. 18F-FDG-PET was done to detect any remaining tumor tissue, and it showed a hot uptake on the lower left occipital area, where a pea-sized nodule formed 2 months later. Dissection and wide excision of the nodule showed metastatic malignant proliferating trichilemmal tumor cells in the lymph nodes.


RESULTS
We were able to take advantage of the high resolution of the 18F-FDG-PET in detecting a metastatic lesion despite its proximity to the central nervous system.


CONCLUSIONS
The 18F-FDG-PET can be used in future malignant proliferating trichilemmal tumor cases to study the metastatic characteristics of this rare tumor.
Jung
Jeanne
J
Department of Dermatology and Cutaneous Biology Research Institute Nuclear Medicine, Yonsei University College of Medicine, Seoul, Korea.
Cho
Sung Bin
SB
Yun
Mijin
M
Lee
Kwang Hoon
KH
Chung
Kee Yang
KY
D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000627:therapeutic use; D006258:Head and Neck Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D006801:Humans; D008207:Lymphatic Metastasis; D019275:Radiopharmaceuticals / Q000627:therapeutic use; D012535:Scalp; D012878:Skin Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery; D014055:Tomography, Emission-Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18