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Proliferating Pilar Tumor Workup

  • Author: Marjon Vatanchi, MD; Chief Editor: William D James, MD  more...
 
Updated: Sep 16, 2015
 

Imaging Studies

Imaging studies are not usually indicated, but they may show a lobulated cystic mass, coarse calcification, or ringlike mineralization.

Because some subcutaneous tumors located in the midline of the body may have connections to the central nervous system (eg, scalp cavernous angioma, which may be part of the symptom complex known as sinus pericranii), imaging tumors in this location with CT or MRI prior to removal should be considered.

The best modality to determine bony invasion or erosion is CT scanning,[15] and proliferating pilar tumors are frequently found as incidental subcutaneous nodules on brain CT scans. They most frequently display isointensity on T1-weighted images and heterogeneous signal on T2-weighted images.[16] However, for deeper tissue invasion, MRI is best.

Additional imaging may be necessary on a case-by-case basis. A 62-year-old with a PTT on the shoulder had a positron emission tomography scan that displayed a high uptake of 18F-FDG (fluorodeoxyglucose).[17] In a different case, an endoscopic ultrasound with fine-needle aspiration was used to discover PPT metastasis to the pancreas in a 65-year-old man.[18]

 

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Procedures

Performing an excisional biopsy is recommended. Send as much of the lesion as possible for pathologic evaluation. Ideally, the entire lesion should be excised and submitted at the time of the biopsy.

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Histologic Findings

The neoplasm is well circumscribed, with islands of squamous epithelium undergoing trichilemmal keratinization. Horn pearls or squamous eddies may be present, as may foci of calcification and glycogen-rich clear cells.

The epithelial cells lining the cyst lack intercellular bridges. The peripheral layers palisade, while the deeper layer cells are swollen.

Anticytokeratin 5/6 may also stain strongly positive in this neoplasm. This is a monoclonal antibody that recognizes high molecular weight keratin intermediate filaments.

An increase in staining of nucleolar organizer regions, an indicator of proliferation, has also been proposed as an adjunct to differentiate benign and malignant proliferating trichilemmal tumors.[19]

Calretinin is a calcium-binding protein member of the EF-hand family and is reported to be focally positive. Calretinin may be helpful to identify the innermost cell layer of the outer root sheath in an anagen hair follicle, with the cutaneous adnexal proliferations showing differentiation toward this structure. Calretinin immunoreactivity supports eccrine differentiation in some sweat gland neoplasms, and it is also useful in identifying neoplasms with ductal sebaceous differentiation.[20]

Immunohistochemical staining with Ki-67, P53, and CD34 has been using to classify malignant PTT from PTT.[21]

A series of histological slides follows:

Proliferating trichilemmal cystic neoplasm. Well-c Proliferating trichilemmal cystic neoplasm. Well-circumscribed neoplasm with central cornified cells (2X). Courtesy of Steve A. McClain, MD.
Proliferating trichilemmal cystic neoplasm (20X). Proliferating trichilemmal cystic neoplasm (20X). Courtesy of Steve A. McClain, MD.
Proliferating trichilemmal cystic neoplasm (400X). Proliferating trichilemmal cystic neoplasm (400X). Note the pleomorphism of keratinocytes and mitotic figures. Courtesy of Steve A. McClain, MD.

Ye et al[9] proposed a stratification of proliferating pilar tumors (PPTs) into the following 3 groups:

  • Group 1 - Circumscribed silhouettes with "pushing" margins; modest nuclear atypia; and an absence of pathologic mitoses, necrosis, and invasion of nerves or vessels
  • Group 2 - Similar to group 1 but manifest as irregular, locally invasive silhouettes with involvement of the deep dermis and subcutis
  • Group 3 - Invasive growth patterns, marked nuclear atypia, pathologic mitotic forms, and geographic necrosis, with or without involvement of nerves or vascular structures.

Group 1 may be regarded as benign, group 2 as having the potential for locally aggressive growth, and group 3 as also having metastatic potential. The latter 2 categories might be equated with low and high grades of malignancy among PPTs of the skin. Occasionally, PPTs have been misdiagnosed at squamous cell carcinomas.[22]

Therefore, determining the malignant potential of a proliferating pilar tumor may be challenging and additional parameters are often needed. For instance, malignant proliferating pilar tumors are more likely to stain positive with p53 and Ki-67 relative to benign proliferating pilar tumors and trichilemmal cysts, and CD34 immunoreactivity may distinguish a malignant proliferating pilar tumor from a squamous cell carcinoma.[22]

The cyst cavity contains amorphous eosinophilic keratin. The content is commonly calcified.

The cyst may also have dedifferentiated parts, further emphasizing the need for careful analysis.[23]

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Contributor Information and Disclosures
Author

Marjon Vatanchi, MD Pediatric Dermatology Research Fellow, Department of Dermatology, SUNY Downstate Medical Center

Marjon Vatanchi, MD is a member of the following medical societies: American Academy of Dermatology, Houston Dermatological Society, Medical Dermatology Society, National Psoriasis Foundation, Texas Dermatological Society

Disclosure: Nothing to disclose.

Coauthor(s)

Daniel Mark Siegel, MD, MS Clinical Professor of Dermatology, Department of Dermatology, State University of New York Downstate Medical Center

Daniel Mark Siegel, MD, MS is a member of the following medical societies: American Academy of Dermatology, American College of Mohs Surgery, American Association for Physician Leadership, American Society for Dermatologic Surgery, American Society for MOHS Surgery, International Society for Dermatologic Surgery

Disclosure: Nothing to disclose.

Rashid M Rashid, MD, PhD Director, Mosaic Clinic Hair Transplant Center of Houston

Rashid M Rashid, MD, PhD is a member of the following medical societies: American Academy of Dermatology, Texas Medical Association, Texas Dermatological Society, International Society of Hair Restoration Surgery, Council for Nail Disorders, Houston Dermatological Society

Disclosure: Nothing to disclose.

Raman K Madan, MD Resident Physician, Department of Dermatology, State University of New York Downstate Medical Center

Disclosure: Nothing to disclose.

Specialty Editor Board

Richard P Vinson, MD Assistant Clinical Professor, Department of Dermatology, Texas Tech University Health Sciences Center, Paul L Foster School of Medicine; Consulting Staff, Mountain View Dermatology, PA

Richard P Vinson, MD is a member of the following medical societies: American Academy of Dermatology, Texas Medical Association, Association of Military Dermatologists, Texas Dermatological Society

Disclosure: Nothing to disclose.

John G Albertini, MD Private Practice, The Skin Surgery Center; Clinical Associate Professor (Volunteer), Department of Plastic and Reconstructive Surgery, Wake Forest University School of Medicine; President-Elect, American College of Mohs Surgery

John G Albertini, MD is a member of the following medical societies: American Academy of Dermatology, American College of Mohs Surgery

Disclosure: Received grant/research funds from Genentech for investigator.

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

Disclosure: Nothing to disclose.

Additional Contributors

R Stan Taylor, MD The JB Howell Professor in Melanoma Education and Detection, Departments of Dermatology and Plastic Surgery, Director, Skin Surgery and Oncology Clinic, University of Texas Southwestern Medical Center

R Stan Taylor, MD is a member of the following medical societies: American Academy of Dermatology, American College of Mohs Surgery, American Medical Association

Disclosure: Nothing to disclose.

Maria Christina Kessides, MD, MS Resident Physician, Department of Dermatology, State University of New York Downstate Medical Center

Disclosure: Nothing to disclose.

Acknowledgements

Amor Khachemoune, MD, CWS Mohs Micrographic Surgery, Dermatopathology, Department of Dermatology, State University of New York Downstate Medical Center; Consulting Staff, Department of Dermatology, Veterans Affairs Medical Center of Brooklyn

Amor Khachemoune, MD, CWS is a member of the following medical societies: American Academy of Dermatology, American Academy of Wound Management, American College of Mohs Micrographic Surgery and Cutaneous Oncology, American Medical Association, American Society for Dermatologic Surgery, and American Society for Laser Medicine and Surgery

Disclosure: Nothing to disclose.

Steve A McClain, MD Clinical Associate Professor, Department of Pathology, The School of Medicine at Stony Brook University Medical Center; Medical Director, Founder and Owner, McClain Laboratories LLC

Steve A McClain, MD is a member of the following medical societies: American Society for Clinical Pathology and College of American Pathologists

Disclosure: McClain Laboratories, LLC Ownership interest Management position

Kimberly Silvers, MD, PhD Staff Physician, Section of Dermatology, Guthrie Clinic

Kimberly Silvers, MD, PhD is a member of the following medical societies: American Academy of Dermatology and Phi Beta Kappa

Disclosure: Nothing to disclose.

References
  1. Wilson-Jones E. Proliferating epidermoid cysts. Arch Dermatol. 1966. 94:11.

  2. Sau P, Graham JH, Helwig EB. Proliferating epithelial cysts. Clinicopathological analysis of 96 cases. J Cutan Pathol. 1995 Oct. 22(5):394-406. [Medline].

  3. López-Ríos F, Rodríguez-Peralto JL, Aguilar A, Hernández L, Gallego M. Proliferating trichilemmal cyst with focal invasion: report of a case and a review of the literature. Am J Dermatopathol. 2000 Apr. 22(2):183-7. [Medline].

  4. Mehregan AH, Lee KC. Malignant proliferating trichilemmal tumors--report of three cases. J Dermatol Surg Oncol. 1987 Dec. 13(12):1339-42. [Medline].

  5. Saida T, Oohara K, Hori Y, Tsuchiya S. Development of a malignant proliferating trichilemmal cyst in a patient with multiple trichilemmal cysts. Dermatologica. 1983. 166(4):203-8. [Medline].

  6. Weiss J, Heine M, Grimmel M, Jung EG. Malignant proliferating trichilemmal cyst. J Am Acad Dermatol. 1995 May. 32(5 Pt 2):870-3. [Medline].

  7. Ramaswamy AS, Manjunatha HK, Sunilkumar B, Arunkumar SP. Morphological spectrum of pilar cysts. N Am J Med Sci. 2013 Feb. 5(2):124-8. [Medline]. [Full Text].

  8. Al-Saleh K, Hooda HS, El-Wakiel H, Safwat R, Bedair A, Eskaf W. Trichilemmal pilar tumor of the scalp: a case report. Gulf J Oncolog. 2012 Jul. 62-4. [Medline].

  9. Ye J, Nappi O, Swanson PE, Patterson JW, Wick MR. Proliferating pilar tumors: a clinicopathologic study of 76 cases with a proposal for definition of benign and malignant variants. Am J Clin Pathol. 2004 Oct. 122(4):566-74. [Medline].

  10. Alessi E, Zorzi F, Gianotti R, Parafioriti A. Malignant proliferating onycholemmal cyst. J Cutan Pathol. 1994 Apr. 21(2):183-8. [Medline].

  11. Wang X, Yang J, Yang W. Multiple proliferating trichilemmal tumors in a middle-aged yellow man. Tumori. 2010 Mar-Apr. 96(2):349-51. [Medline].

  12. Karaca S, Kulac M, Dilek FH, Polat C, Yilmaz S. Giant proliferating trichilemmal tumor of the gluteal region. Dermatol Surg. 2005 Dec. 31(12):1734-6. [Medline].

  13. Avinoach I, Zirkin HJ, Glezerman M. Proliferating trichilemmal tumor of the vulva. Case report and review of the literature. Int J Gynecol Pathol. 1989. 8(2):163-8. [Medline].

  14. Kang SJ, Wojno TH, Grossniklaus HE. Proliferating trichilemmal cyst of the eyelid. Am J Ophthalmol. 2007 Jun. 143(6):1065-7. [Medline].

  15. Chang SJ, Sims J, Murtagh FR, McCaffrey JC, Messina JL. Proliferating trichilemmal cysts of the scalp on CT. AJNR Am J Neuroradiol. 2006 Mar. 27(3):712-4. [Medline].

  16. Gossner J, Larsen J. Incidental subcutaneous nodules on the scalp in patients undergoing CT of the brain; frequency, appearance, and differential diagnosis. Clin Radiol. 2010 May. 65(5):427-8. [Medline].

  17. Leyendecker P, de Cambourg G, Mahé A, Imperiale A, Blondet C. 18F-FDG PET/CT Findings in a Patient With a Proliferating Trichilemmal Cyst. Clin Nucl Med. 2015 Jul. 40 (7):598-9. [Medline].

  18. Trikudanathan G, Shaukat A, Bakman Y. Proliferating Pilar Tumor of Scalp Metastasizing to Pancreas: Diagnosis With Endoscopic Ultrasound-guided Fine-needle Aspiration. Clin Gastroenterol Hepatol. 2015 Apr 30. [Medline].

  19. Shet T, Modi C. Nucleolar organizer regions (NORs) in simple and proliferating trichilemmal cysts (pilar cysts and pilar tumors). Indian J Pathol Microbiol. 2004 Oct. 47(4):469-73. [Medline].

  20. González-Guerra E, Kutzner H, Rutten A, Requena L. Immunohistochemical study of calretinin in normal skin and cutaneous adnexal proliferations. Am J Dermatopathol. 2012 Jul. 34(5):491-505. [Medline].

  21. Rangel-Gamboa L, Reyes-Castro M, Dominguez-Cherit J, Vega-Memije E. Proliferating trichilemmal cyst: the value of ki67 immunostaining. Int J Trichology. 2013 Jul. 5 (3):115-7. [Medline].

  22. Chaichamnan K, Satayasoontorn K, Puttanupaab S, Attainsee A. Malignant proliferating trichilemmal tumors with CD34 expression. J Med Assoc Thai. 2010 Nov. 93 Suppl 6:S28-34. [Medline].

  23. Masui Y, Komine M, Kadono T, Ishiura N, Maekawa T, Ihn H. Proliferating tricholemmal cystic carcinoma: a case containing differentiated and dedifferentiated parts. J Cutan Pathol. 2008 Oct. 35 Suppl 1:55-8. [Medline].

  24. Alici O, Keles MK, Kurt A. A Rare Cutaneous Adnexal Tumor: Malignant Proliferating Trichilemmal Tumor. Case Rep Med. 2015. 2015:742920. [Medline].

  25. Nyquist GG, Mumm C, Grau R, Crowson AN, Shurman DL, Benedetto P, et al. Malignant proliferating pilar tumors arising in KID syndrome: a report of two patients. Am J Med Genet A. 2007 Apr 1. 143(7):734-41. [Medline].

  26. Eskander A, Ghazarian D, Bray P, Dawson LA, Goldstein DP. Squamous cell carcinoma arising in a proliferating pilar (trichilemmal) cyst with nodal and distant metastases. J Otolaryngol Head Neck Surg. 2010 Oct. 39(5):E63-7. [Medline].

  27. Amaral AL, Nascimento AG, Goellner JR. Proliferating pilar (trichilemmal) cyst. Report of two cases, one with carcinomatous transformation and one with distant metastases. Arch Pathol Lab Med. 1984 Oct. 108(10):808-10. [Medline].

  28. Batman PA, Evans HJ. Metastasising pilar tumour of scalp. J Clin Pathol. 1986 Jul. 39(7):757-60. [Medline].

  29. Folpe AL, Reisenauer AK, Mentzel T, Rütten A, Solomon AR. Proliferating trichilemmal tumors: clinicopathologic evaluation is a guide to biologic behavior. J Cutan Pathol. 2003 Sep. 30(8):492-8. [Medline].

  30. Janitz J, Wiedersberg H. Trichilemmal pilar tumors. Cancer. 1980 Apr 1. 45(7):1594-7. [Medline].

  31. Kanitakis J, Bourchany D, Faure M, Claudy A. Expression of the hair stem cell-specific keratin 15 in pilar tumors of the skin. Eur J Dermatol. 1999 Jul-Aug. 9(5):363-5. [Medline].

  32. Mann B, Salm R, Azzopardi JG. Pilar tumour: a distinctive type of trichilemmoma. Diagn Histopathol. 1982 Jul-Sep. 5(3):157-67. [Medline].

  33. Mannan AA, Mirza K. Proliferating trichilemmal tumor in the chest wall: report of a rare case. Gulf J Oncolog. 2008 Jul. (4):63-5. [Medline].

  34. Morgan RF, Dellon A, Hoopes JE. Pilar tumors. Plast Reconstr Surg. 1979 Apr. 63(4):520-4. [Medline].

  35. Plumb SJ, Argenyi ZB, Stone MS, De Young BR. Cytokeratin 5/6 immunostaining in cutaneous adnexal neoplasms and metastatic adenocarcinoma. Am J Dermatopathol. 2004 Dec. 26(6):447-51. [Medline].

  36. Poiares Baptista A, Garcia E Silva L, Born MC. Proliferating trichilemmal cyst. J Cutan Pathol. 1983 Jun. 10(3):178-87. [Medline].

 
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Proliferating trichilemmal cystic neoplasm. Well-circumscribed neoplasm with central cornified cells (2X). Courtesy of Steve A. McClain, MD.
Proliferating trichilemmal cystic neoplasm (20X). Courtesy of Steve A. McClain, MD.
Proliferating trichilemmal cystic neoplasm (400X). Note the pleomorphism of keratinocytes and mitotic figures. Courtesy of Steve A. McClain, MD.
 
 
 
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