The same errors that spawned, sustained, and continue to spur the notions of "atypical" Spitz's nevus, "malignant" Spitz's nevus, and "metastasizing" Spitz's nevus are animating of 3 other concepts flawed equally, namely, those of "atypical blue nevus," "malignant blue nevus," and "metastasizing blue nevus." Our intention here is to compel to the conclusion, by way of critique in historical perspective, that all neoplasms claimed to be "malignant blue nevus" and "metastasizing blue nevus;" in fact, are melanomas, that all "atypical blue nevi" are either a nevus or a melanoma, and that the trio of curious designations that serve as title of this work are mere evasions transparently from a diagnosis, straightforwardly, of 1 of only 3 possibilities, to wit, "blue nevus," melanoma, or melanoma in association with a "blue nevus." Rather than admit uncertainty forthrightly, those who employ circumlocutions that we deplore, such as those under scrutiny here, resort to linguistic maneuvers that, at first blush, seem to have the cachet of scholarship (the jargon used being in keeping with a slew of other well-accepted, but equally bogus diagnoses in [dermato]pathology, among those being "minimal deviation melanoma," "borderline melanoma," "nevoid melanoma," "potentially low-grade melanocytic neoplasm," and "melanocytic proliferation of uncertain biologic potential"). All those terms and phrases are constructed in a manner designed to make them appear to convey unbridled confidence on the part of a histopathologist, rather than what they are in actuality, that is, a cover abjectly for tentativeness. Scrutiny of the lingo, in very abbreviated form, just catalogued reveals it to be devoid of content utterly. For example, "malignant blue nevus" and "metastasizing blue nevus" not only are contradictions in terms, but they are outrageous violations of principles fundamental to classic Virchowian pathology. We seek here to debunk that claptrap in the same manner we did "atypical Spitz's nevus," "malignant Spitz's nevus," and "metastasizing Spitz's nevus." It is our hope that readers will consider our arguments worthy because they are logical, will find them convincing because they are irrefutable, and will incorporate the lessons communicated through them so that their own professional life, pathology as a discipline, and, ultimately, patients, are the beneficiaries.

Congenital pauci-melanotic cellular blue nevus.J Cutan Pathol. 2004 Apr;31(4):312-7.

Unusual or atypical melanocytic nevi can be confused with malignant melanoma. Two patients are presented here with a rare variant of melanocytic nevus. Both were men. One was 39 years old and sought medical attention after trauma of a "congenital mole". The other was 24 years old and presented with a history of a slowly growing lesion, which had been known since childhood. In both patients, the lesion occurred on the buttock. They were dermal and superficial subcutaneous nodules measuring 1.5 and 2.3 cm in greatest dimension, respectively. The tumors were composed of densely cellular fascicles of melanocytes arranged in a lobulated growth pattern. Rare nests of small epithelioid melanocytes were also seen. No melanin pigment was seen on hematoxylin and eosin-stained sections. Focal minimal pigment was noted by Fontana-Masson stain in one case. Involvement of numerous peripheral nerve trunks by fusiform melanocytes was a prominent feature. Rare mitotic figures were seen in melanocytes [1-2 mitoses per 50 high-power fields (HPF)]. The MIB-1 labeling index was low (less than 5% of the lesional cell population was immunopositive). Both tumors were excised with negative surgical margins. One patient underwent sentinel lymph node biopsy because there was controversy regarding the biologic potential of the lesion. No melanocytic tumor deposits were found in the lymph nodes. On clinical follow up of 11 years and 18 months after complete excision, both patients are alive and well with no evidence of recurrence. We regard these lesions as congenital monophasic and pauci-melanotic variants of cellular blue nevus. The nevi are presented here to enhance our knowledge of the morphologic spectrum of melanocytic tumors and to help avoid confusion with malignant melanoma.