Follicular Infundibulum Tumor Workup: Histologic Findings
Follicular Infundibulum Tumor Workup: Histologic Findings
Tumor of the follicular infundibulum is a histologic diagnosis. Most cases typically resemble the original description by Mehregan and Butler.A platelike fenestrated subepidermal tumor extends horizontally under the epidermis with multiple cordlike connections to the overlying epidermis. Upon serial sectioning, connections between the pale-staining, glycogen-containing, tumoral keratinocytes and the external root sheath of adjacent hair follicles usually can be found. Peripheral palisading of the basal cells is present.
Peripheral palisading of basaloid cells frequently is observed. Pale staining results from the presence of glycogen analogous to the external root sheath and is confirmed by periodic acid-Schiff (PAS) stain with diastase digestion. A dense band or brushlike network of elastic fibers frequently is demonstrated at the border of the tumor, again analogous to the normal hair follicle. This can be observed readily using Verhoeff, van Gieson, or orcein stains.
A case report from 2001 noted foci of sebaceous differentiation within the fenestrated epithelium.
Treatment & Management
Brad S Graham, MD Consulting Staff, Dermatology Associates of Tyler
Brad S Graham, MD is a member of the following medical societies: Alpha Omega Alpha, Texas Dermatological Society, American Academy of Dermatology, American Society of Dermatopathology
Specialty Editor Board
David F Butler, MD Section Chief of Dermatology, Central Texas Veterans Healthcare System; Professor of Dermatology, Texas A&M University College of Medicine; Founding Chair, Department of Dermatology, Scott and White Clinic
David F Butler, MD is a member of the following medical societies: American Medical Association, Alpha Omega Alpha, Association of Military Dermatologists, American Academy of Dermatology, American Society for Dermatologic Surgery, American Society for MOHS Surgery, Phi Beta Kappa
Edward F Chan, MD Clinical Assistant Professor, Department of Dermatology, University of Pennsylvania School of Medicine
Edward F Chan, MD is a member of the following medical societies: American Academy of Dermatology, American Society of Dermatopathology, Society for Investigative Dermatology
Chief Editor
William D James, MD Paul R Gross Professor of Dermatology, Vice-Chairman, Residency Program Director, Department of Dermatology, University of Pennsylvania School of Medicine
William D James, MD is a member of the following medical societies: American Academy of Dermatology, Society for Investigative Dermatology
References
Tumor of the follicular infundibulum shows a platelike dermal tumor with anastomosing islands and cords with connections to the overlying epidermis and horn cysts (hematoxylin and eosin stain, 40X magnification).
Tumor of the follicular infundibulum shows epidermal connections, horn cysts, and anastomosing islands (hematoxylin and eosin stain, 100X magnification).
Tumor of the follicular infundibulum shows epidermal connections, peripheral palisading, and horn cyst (hematoxylin and eosin stain, 400X magnification).
Histologic Findings
Tumor of the follicular infundibulum is a histologic diagnosis. Most cases typically resemble the original description by Mehregan and Butler.A platelike fenestrated subepidermal tumor extends horizontally under the epidermis with multiple cordlike connections to the overlying epidermis. Upon serial sectioning, connections between the pale-staining, glycogen-containing, tumoral keratinocytes and the external root sheath of adjacent hair follicles usually can be found. Peripheral palisading of the basal cells is present.
Peripheral palisading of basaloid cells frequently is observed. Pale staining results from the presence of glycogen analogous to the external root sheath and is confirmed by periodic acid-Schiff (PAS) stain with diastase digestion. A dense band or brushlike network of elastic fibers frequently is demonstrated at the border of the tumor, again analogous to the normal hair follicle. This can be observed readily using Verhoeff, van Gieson, or orcein stains.
A case report from 2001 noted foci of sebaceous differentiation within the fenestrated epithelium.
Treatment & Management
Brad S Graham, MD Consulting Staff, Dermatology Associates of Tyler
Brad S Graham, MD is a member of the following medical societies: Alpha Omega Alpha, Texas Dermatological Society, American Academy of Dermatology, American Society of Dermatopathology
Specialty Editor Board
David F Butler, MD Section Chief of Dermatology, Central Texas Veterans Healthcare System; Professor of Dermatology, Texas A&M University College of Medicine; Founding Chair, Department of Dermatology, Scott and White Clinic
David F Butler, MD is a member of the following medical societies: American Medical Association, Alpha Omega Alpha, Association of Military Dermatologists, American Academy of Dermatology, American Society for Dermatologic Surgery, American Society for MOHS Surgery, Phi Beta Kappa
Edward F Chan, MD Clinical Assistant Professor, Department of Dermatology, University of Pennsylvania School of Medicine
Edward F Chan, MD is a member of the following medical societies: American Academy of Dermatology, American Society of Dermatopathology, Society for Investigative Dermatology
Chief Editor
William D James, MD Paul R Gross Professor of Dermatology, Vice-Chairman, Residency Program Director, Department of Dermatology, University of Pennsylvania School of Medicine
William D James, MD is a member of the following medical societies: American Academy of Dermatology, Society for Investigative Dermatology
References
- Mehregan AH, Butler JD. A tumor of follicular infundibulum. Report of a case. Arch Dermatol. 1961 Jun. 83:924-7. [Medline].
- Koch B, Rufli T. Tumor of follicular infundibulum. Dermatologica. 1991. 183(1):68-9. [Medline].
- Kossard S, Finley AG, Poyzer K, Kocsard E. Eruptive infundibulomas. A distinctive presentation of the tumor of follicular infundibulum. J Am Acad Dermatol. 1989 Aug. 21(2 Pt 2):361-6. [Medline].
- Sartorelli AC, Leite FE, Friedman IV, Friedman H. Vitiligoid hypopigmented macules and tumor of the follicular infundibulum. An Bras Dermatol. 2009 Jan-Feb. 84(1):68-70. [Medline]. [Full Text].
- Cheng AC, Chang YL, Wu YY, Hu SL, Chuan MT. Multiple tumors of the follicular infundibulum. Dermatol Surg. 2004 Sep. 30(9):1246-8. [Medline].
- Martin JE, Hsu MY, Wang LC. An unusual clinical presentation of multiple tumors of the follicular infundibulum. J Am Acad Dermatol. 2009 May. 60(5):885-6. [Medline].
- Cribier B, Grosshans E. Tumor of the follicular infundibulum: a clinicopathologic study. J Am Acad Dermatol. 1995 Dec. 33(6):979-84. [Medline].
- Mahalingam M, Bhawan J, Finn R, Stefanato CM. Tumor of the follicular infundibulum with sebaceous differentiation. J Cutan Pathol. 2001 Jul. 28(6):314-7. [Medline].
- Kolenik SA 3rd, Bolognia JL, Castiglione FM Jr, Longley BJ. Multiple tumors of the follicular infundibulum. Int J Dermatol. 1996 Apr. 35(4):282-4. [Medline].
- MacGregor JL, Campanelli C, Friedman PC, Desciak E. Basal cell and squamous cell carcinoma occurring within a field of multiple tumors of the follicular infundibulum. Dermatol Surg. 2008 Nov. 34(11):1567-70. [Medline].
- Abbas O, Mahalingam M. Tumor of the follicular infundibulum: an epidermal reaction pattern?. Am J Dermatopathol. 2009 Oct. 31(7):626-33. [Medline].
- Weyers W, Hörster S, Diaz-Cascajo C. Tumor of follicular infundibulum is Basal cell carcinoma. Am J Dermatopathol. 2009 Oct. 31(7):634-41. [Medline].
Tumor of the follicular infundibulum shows a platelike dermal tumor with anastomosing islands and cords with connections to the overlying epidermis and horn cysts (hematoxylin and eosin stain, 40X magnification).
Tumor of the follicular infundibulum shows epidermal connections, horn cysts, and anastomosing islands (hematoxylin and eosin stain, 100X magnification).
Tumor of the follicular infundibulum shows epidermal connections, peripheral palisading, and horn cyst (hematoxylin and eosin stain, 400X magnification).
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