Myxoid Spitz Nevi: Report of 6 Cases

Abstract

Mucin deposition in Spitz nevus seems to be a very rare phenomenon, as there have only been 3 cases previously published. We report 6 additional cases, half of them in women, and half in men. The ages of the patients varied from 5 to 47 years (mean = 30.17). Sizes of the nevi varied from 3 to 6 mm. Four lesions were located on the extremities, whereas one was located on the trunk (there was no clinical information about the other). A vascular lesion was suspected in 2 cases. Excision with clear margins was achieved in all cases but one. So far, there have been no recurrences after follow-ups varying from 1 to 5 years. The biopsy showed a symmetrical melanocytic Spitz nevus in all cases. Three cases were compound, and 3 cases were junctional nevi. The epidermis was either acanthotic or hyperplastic in all cases, with no epidermal consumption. Kamino bodies were found in 4 cases. The deposit of mucin was moderate in 5 cases and mild in one case. Mucin was found in the stroma between the dermal melanocytes in cases of compound nevi and in the melanocytic nests of the junctional component.

The Spectrum of Spitz Melanocytic Lesions: From Morphologic Diagnosis to Molecular Classification

“…Myxoid Spitz Nevus is an exceedingly rare variant of SN, with fewer than 10 cases published in the literature ( 36 , 155 – 157 ). First described in 1990, this variant presents with a myxoid stroma and mucin deposits may be present in the stroma between either isolated or nests of melanocytes ( 155 – 157 ). Clinically, these lesions are small, symmetrical, and may be compound or junctional ( 157 ).…”

“…First described in 1990, this variant presents with a myxoid stroma and mucin deposits may be present in the stroma between either isolated or nests of melanocytes ( 155 – 157 ). Clinically, these lesions are small, symmetrical, and may be compound or junctional ( 157 ). One study detected Kamino bodies in four out of six cases of Myxoid SN ( 157 ).…”

“…Clinically, these lesions are small, symmetrical, and may be compound or junctional ( 157 ). One study detected Kamino bodies in four out of six cases of Myxoid SN ( 157 ). These lesions bear a strong resemblance to malignant myxoid melanomas and care must be taken to rule out malignancy ( 157 , 158 ).…”

Genetic Studies on a Case of Eruptive Disseminated Spitz Nevus and Review of Other 33 Cases

“…This is a very rare phenomenon with very few cases published. 33 Other than the myxoid phenotype, such lesions seem to behave as any other nonmyxoid Spitz tumor. Some of the published eruptive melanocytic conditions have been associated with cardiac or neurologic disorders.…”

Uncommon Histopathological Variants of Malignant Melanoma. Part 2

“…8 Myxoid changes have been recently described also in Spitz nevi. 19 Detection of features of conventional melanoma at the periphery of myxoid areas and/or within the epidermis represents a useful diagnostic clue in challenging cases. 9…”