Several proof-of-principle studies showed potential applications of FISH to solve a variety of diagnostic dilemmas in the evaluation of melanocytic tumors, including differentiating blue nevus
-like metastasis from blue nevus
, mitotically active nevus from nevoid melanoma, and dysplastic nevus from superficial spreading melanoma.
Pathologic diagnosis: Benign tumors Diagnosis n (%) Hemangioma 5 (9) Ossifying fibroma 4 (7) Adnexal neoplasm 1 (2) Ameloblastic fibro-odontoma 1 (2) Benign fibrous histiocytoma 1 (2) Blue nevus
1 (2) Compound nevus 1 (2) Epithelioma adenoides cysticum 1 (2) Giant cell granuloma 1 (2) Lymphangioma 1 (2) Neurofibroma 1 (2) Osteochondroma 1 (2) Port wine stain 1 (2) Spitz nevus 1 (2) Xanthogranuloma 1 (2) Total 22 (41) Table 4.
Also, the melanocytes of the blue nevus
tend to be more slender than the plumper tumor cells of the hyalinizing Spitz nevus.
of the prostate, also called pigmented melanocytosis and prostatic pigmented nevohyperplasia, is similar to its cutaneous counterpart.
Based on this single case, it was suggested that malignant DPN may harbor a more favorable prognosis than conventional melanoma because of its low-grade malignant potential, akin to pigment-synthesizing melanoma or malignant blue nevus
1,2) This review focuses only on blue nevus
and its variants.
Almost a decade ago, the authors independently recognized that a subset of darkly pigmented melanocytic metastasizing tumors histologically reminiscent of melanomas occurring in animals, sometimes referred to as socalled animal-type melanomas, are histologically very similar to benign epithelioid blue nevus
described in patients with Carney complex and also occurring sporadically, unassociated with the syndrome.
They also discuss in great detail the relationship of pigmented epithelioid melanocytoma and epithelioid blue nevus
of Carney complex.
Most variants of cutaneous nevi including combined nevus, balloon cell nevus, Spitz nevus, pigmented spindle cell nevus, and blue nevus
have been reported in the conjunctiva.
In view of the results of a clinicopathologic analysis of 40 patients with tumors previously diagnosed as "animal-type or pigment-synthesizing melanoma" or "epithelioid blue nevus
," Zembowicz et al (101) proposed the term pigmented epithelioid melanocytoma (PEM) to encompass these melanocytic tumors.
Bland-appearing (pseudobenign) lesions can resemble a variety of other spindle cell proliferations, particularly proliferating scars and sclerosing blue nevus
2,5,9) Benign lesions with relatively low risk include congenital melanocytic nevus, nevus of Ota, nevus of Ito, and cellular blue nevus