Table 1.

Clinical information and microscopical findings of all four cases

Case	Diagnosis	Age (y)	Sex	Relevant history	Site	Clinical appearance	Architecture	Epidermis	Cyto-morphology	Pigmentation	Mitotic figures	Nuclear atypia	Recurrence	Follow-up (months)
1	MELTUMP (perhaps AST)	17	F	No	Left lower arm	Elevated, round, erythematous papule. Diameter 8 mm. Had grown.	Symmetrical, dermal, slightly wedge-shaped. Desmoplastic stroma.	Hyperplastic	Epithelioid to spindle-shaped. Pale, eosinophilic cytoplasm.	No	0	Moderate to severe	No	4
2	SSM	16	M	No	Right wrist	Elevated, 2 × 2 mm, showing dark spot.	Symmetrical, compound, into superficial dermis. Large junctional nests. Few melanocytes in epidermis, no ascension.	Hyperplastic, hyperkeratosis	Epithelioid to spindle-shaped. Eosinophilic cytoplasm. Large nuclei, prominent nucleoli and vacuoles.	Slight	1 (junction)	Moderate	No	2
3	Variant Spitz nevus	48	F	No	Left upper leg	Clinical atypical nevus, black to brown, sharply demarcated, 5 × 4 mm (see clinical pictures).	Symmetrical, compound. Nests and solitary melanocytes at junction, focal ascension. In dermis partly smaller melanocytes with focally naevoid aspect. Desmoplastic stroma.	Hyperplastic, hyper- and parakeratosis	Epithelioid to spindle-shaped. Eosinophilic cytoplasm. Enlarged nuclei, nucleoli	Yes	1 (upper dermis)	Moderate	No	2
4	Probably Spitz nevus, at most low-grade MELTUMP (perhaps AST)	68	M	No	Right lower back	Nodule, variable pigmentation. Diameter 4 mm. Present for at least 4 years, unchanged (see clinical pictures). No clinical suspicion for malignancy.	Symmetrical, dermal, slightly wedge-shaped. Maturation towards deeper parts.	Normal	Spindle-shaped. Pale, eosinophilic cytoplasm.	No	0	No	No	7

AST, atypical Spitz tumor; F, female; M, male; MELTUMP, melanocytic tumor of unknown malignant potential; SSM, superficial spreading melanoma; y, years