neurocristic hamartoma

Digital cases

 Case 194 (HPC:194)

Definition: Cutaneous neurocristic hamartoma (NCH) is a rare, pigmented lesion consisting of cells that aberrantly develop from the neurocrest. In addition to a dermal melanocytic component, NCH can also harbor neurosustentacular and neuromesenchymal components.

NCH has many features in common with other dermal melanocytic neoplasm, such as blue nevi.

Neurocristic cutaneous hamartomas result from aberrant development of the neuromesenchyme. Thus, the elements within these tumors reflect the spectrum of differentiation that results from migration of neural crest-derived cells.

A dermal melanocytic component is the dominant feature in some lesions, while neurosusenticular and neuromesenchymal components can dominated in other tumors.

The melanocytic component is positive for S-100 protein and HMB-45. The surrounding stroma shows tactoid bodies and increased CD34 staining.

Neurocristic cutaneous hamartomas represent dysplastic development of neural crest-derived cells.

Although melanocytic cells have been previously reported to be the dominant cell population, neurosusentacular and neuromesenchymal cells also may be the principal component.

In cephalic areas, the neuromesenchyme may not only be an important component of the tumor, but may also effect the development of the overlying epithelium and adnexal structures.

Although none of these cases presents evidence of malignant transformation, identification of these tumors could be important if malignant transformation results in the development of tumors with a distinctive biologic behavior.

Variants

 malignant neurocristic hamartoma (21934481)

Differential diagnosis

Recognition of NCH is important not only because of the potential for misinterpretation as melanoma, but also because melanoma arise within these lesions over an unpredictable time frame and remain undetected because of the deep location and already pigmented background.

Open access references

 Neurocristic cutaneous hamartoma of the scalp. Kim SK, Kim YC. Ann Dermatol. 2009 Nov;21(4):396-8. PMID: 20523831 [Free]

References

 Malignant Neurocristic Hamartoma: A Tumor Distinct From Conventional Melanoma and Malignant Blue Nevus. Linskey KR, Dias-Santagata D, Nazarian RM, Le LP, Lam Q, Bellucci KS, Robinson-Bostom L, Mihm MC, Hoang MP. Am J Surg Pathol. 2011 Sep 19. PMID: 21934481

 Extensive Neurocristic Hamartoma With Bone Marrow Involvement. Conrad DM, Chaplin A, Walsh NM, Pasternak S. Am J Dermatopathol. 2010 Apr 20. PMID: 20414093

 The spectrum of neurocristic cutaneous hamartoma: clinicopathologic and immunohistochemical study of three cases. Smith KJ, Mezebish D, Williams J, Elgart ML, Skelton HG. Ann Diagn Pathol. 1998 Aug;2(4):213-23. PMID: 9845741

 Extensive neurocristic hamartoma with bone marrow involvement. Conrad DM, Chaplin A, Walsh NM, Pasternak S. Am J Dermatopathol. 2010 Jul;32(5):486-8. PMID: 20414093

 Extensive neurocristic hamartoma with skeletal muscle involvement. Denlinger CE, Slingluff CL Jr, Mihm MC Jr, Patterson JW. J Cutan Pathol. 2007 Aug;34(8):634-9. PMID: 17640234

 Polypoid dermal dendrocytic hamartoma in a giant congenital melanocytic nevus. Drut R. Int J Surg Pathol. 2007 Jan;15(1):73-6. PMID: 17172504

 Cutaneous neurocristic hamartoma with blue naevus-like features and plexiform dermal hyperneury. Karamitopoulou-Diamantis E, Paredes B, Vajtai I. Histopathology. 2006 Sep;49(3):326-8. PMID: 16918988

 Dermal melanocytic proliferation with features of a plaque-type blue nevus and neurocristic hamartoma. Bevona C, Tannous Z, Tsao H. J Am Acad Dermatol. 2003 Nov;49(5):924-9. PMID: 14576682

 The spectrum of neurocristic cutaneous hamartoma: clinicopathologic and immunohistochemical study of three cases. Smith KJ, Mezebish D, Williams J, Elgart ML, Skelton HG. Ann Diagn Pathol. 1998 Aug;2(4):213-23. PMID: 9845741

 Neurocristic cutaneous hamartoma: a distinctive dermal melanocytosis with an unknown malignant potential. Mezebish D, Smith K, Williams J, Menon P, Crittenden J, Skelton H. Mod Pathol. 1998 Jun;11(6):573-8. PMID: 9647596

 Cutaneous malignant melanotic neurocristic tumors arising in neurocristic hamartomas. A melanocytic tumor morphologically and biologically distinct from common melanoma. Pearson JP, Weiss SW, Headington JT. Am J Surg Pathol. 1996 Jun;20(6):665-77. PMID: 8651345

 Pilar neurocristic hamartoma. Crowson AN, Magro CH, Clark WH. J Am Acad Dermatol. 1996 Apr;34(4):715. PMID: 8601674

 Malignant melanoma arising in a blue nevus with features of pilar neurocristic hamartoma. Pathy AL, Helm TN, Elston D, Bergfeld WF, Tuthill RJ. J Cutan Pathol. 1993 Oct;20(5):459-64. PMID: 8300932

 Two cases of nevus fuscocaeruleus with pain, including a case of pilar neurocristic hamartoma. Kikuchi I, Inoue S, Taketomi I, Ono T. J Dermatol. 1983 Jun;10(3):275-80. PMID: 6358316

 Pilar neurocristic hamartoma: its relationship to blue nevus and equine melanotic disease. Tuthill RJ, Clark WH Jr, Levene A. Arch Dermatol. 1982 Aug;118(8):592-6. PMID: 7103529