J Korean Soc Radiol.  2016 Jun;74(6):389-393. 10.3348/jksr.2016.74.6.389.

Recurrent Proliferating Trichilemmal Tumor with Malignant Change on the F-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography

• Moon EH
• Kim MW
• Kim YJ
• Yoo SB
• Nam KH

• KMID: 2164816
• DOI: http://doi.org/10.3348/jksr.2016.74.6.389

Abstract

F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography scan has been used for the diagnosis, assessment of treatment response, and follow-up of various neoplasms. Proliferating trichilemmal cyst or tumor (PTT) is a rare neoplasm, originated from the outer root sheath of a hair follicle. Because this tumor has unpredictable biological and clinical behavior, the long-term clinical follow-up is necessary to detect metastasis or recurrence. We reported a case of recurrent malignant PTT on scalp that showed increased FDG uptake.

MeSH Terms

Diagnosis
Electrons*
Fluorodeoxyglucose F18
Follow-Up Studies
Hair Follicle
Neoplasm Metastasis
Positron-Emission Tomography
Recurrence
Scalp
Fluorodeoxyglucose F18

Figure

• 

  Fig. 1 A 3 cm-sized fixed mass with discrete margin (arrows) on the scalp of right occipital area.

• 

  Fig. 2 MRI of a 49-year-old male with scalp mass. A, B. Axial T1-weighted and T2-weighted MR image shows an approximately 3 cm-sized, well-defined soft tissue mass with low signal intensity on the right occipital scalp. C, D. Axial (C) and sagittal (D) enhanced T1-weighted MR image shows heterogeneously enhanced, soft tissue mass (arrow) on the right occipital scalp.

• 

  Fig. 3 F-18 FDG PET/CT shows a well-defined soft tissue mass (arrow) with focal FDG uptake (SUVmax = 8.18) on the right occipital scalp and detects no metastasis in other site. A. Sagittal view of PET. B. Axial view of PET/CT. F-18 FDG PET/CT = F-18 fluorodeoxyglucose positron emission tomography/computed tomography, SUVmax = maximum standardized uptake value

• 

  Fig. 4 The histopathology of the excised mass from the right occipital scalp. A. Pushing borders of squamous epithelial cells with irregular lobular pattern and central amorphous keratin materials (trichilemmal-type keratinization) (H&E, × 100). B. Tumor cells with infiltrative growth into stroma and moderate nuclear atypia (H&E, × 200). H&E = hematoxylin and eosin

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