dermal dendrocytic hamartoma

Synospsis

 asymptomatic congenital lesion
 medallion-shaped, well-defined cutaneous tumors
 slightly atrophic appearance
 fusiform-cell tumor

Immunohistochemistry

 CD34+
 factor XIIIa+
 fascin+

Associoations

 Giant congenital melanocytic nevus (CMN) (17172504)

• Giant congenital melanocytic nevus (CMN) might be complicated by the development of several tumor types, mainly melanoma and rhabdomyosarcoma, but also poorly differentiated neoplasms.
• Striking polypoid exophytic masses occasionally result from neuroectodermal and neuromesenchymal hamartomatous overgrowths, which lends support to the concept of pluripotential melanoblastomatous and neurocristic origin of these lesions.
• There are some examples of dermal hamartomatous polypoid CD34(+) fibrogenic proliferation devoid of melanin, namely a dendrocytoma, surrounded by the melanocytes from the nevus, located in the skin of the scrotum against a background of giant CMN.

Electron microscopy

 typical features of dermal dendrocytes

Differential diagnosis

The differential diagnosis included:
 dermatofibrosarcoma protuberans
 giant-cell fibroblastoma
 angiofibroma
 Bednar tumor
 neurocristic cutaneous hamartoma

See also

 dendrocytic tumors

References

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

 Rodriguez-Jurado R, Palacios C, Duran-McKinster C, Mercadillo P, Orozco-Covarrubias L, Saez-de-Ocariz Mdel M, Ruiz-Maldonado R. Medallion-like dermal dendrocyte hamartoma: a new clinically and histopathologically distinct lesion. J Am Acad Dermatol. 2004 Sep;51(3):359-63. PMID: 15337977