Sclerosing 'mucinous' blue naevus

Abundant mucin deposition is an unusual finding in melanocytic naevi. We describe the first example, to our knowledge, of a sclerosing blue naevus with an abundant mucinous stroma in two unrelated patients. This uncommon variant of blue naevus should be differentiated from desmoplastic-neurotropic melanoma, in which the presence of mucin stromal deposition is a more typical finding.     

Disseminated blue naevus and malignant blue naevus associated with excessive aromatase syndrome

We report a case of a 17-year-old boy who had a giant congenital blue naevus with multiple satellite pigmented lesions. Later the patient developed melanoma arising in the pre-existing lesion. He also had gynaecomastia and was diagnosed as having aromatase excess syndrome. To our knowledge, the association of these two rare conditions has not been previously reported. Further studies should be performed to investigate this unusual combination, which may have a genetic, endocrine or local cutaneous link leading to its occurrence.     

色痣和蓝痣的电镜观察

对4例色痣和2例蓝痣进行了电子显微镜观察.发现色痣的痣细胞中充满着许多第皿期和第N期黑素小体.蓝痣的黑素细胞在真皮深部.胞质中的黑素颗粒也相当多.在色痣和蓝痣的痣细胞中可见含黑素的大球形体.可能代表退行现象,也许是溶酶体吞噬了退变的黑素颗粒而形成的.最后讨论了色痣和蓝痣临床色泽差别的原因,蓝痣除黑素细胞部位深、受折光物理因素影响外.细胞中黑幸小体的含量、着色程度也有一定影响.     

Homogeneous blue pigmentation in dermatofibroma simulating a blue naevus

A case with a pigmented skin lesion that was diagnosed as a blue naevus on clinical and dermoscopic grounds and histopathologically confirmed as a dermatofibroma is presented. By means of this case, we define dermatofibroma as a new exception for 'homogeneous blue pigmentation' on dermoscopy.     

Subungual and periungual congenital blue naevus

Subungual pigmented lesions should raise concern about malignant melanoma. Blue naevus of the nail apparatus is a rare entity, with only ten cases described in the literature. We report a 21-year-old Hispanic woman with a slowly enlarging 1.7 × 2.3-cm subungual and periungual pigmented plaque present since birth on her right second toe. Initial biopsy was consistent with a blue naevus of the cellular type and, given the recent clinical change and periungual extension, complete excision was recommended. The entire nail unit was resected down to periosteum with prior avulsion of the nail plate. Reconstruction was performed with a full-thickness skin graft. Follow up at 1 year revealed well-healed graft and donor sites with complete return of function. We present a case of a congenital subungual and periungual blue naevus of the cellular type and review the literature on this rare presentation of a congenital blue naevus.     

Malignant blue naevus with distant subcutaneous metastasis

Malignant blue naevus is a distinct but rarely documented variant of malignant melanoma, and we describe the triple recurrence of a suprapatellar cellular blue naevus over 12 years in a middle-aged woman. Staging investigations revealed a distant subcutaneous metastasis of the right thigh. Immunohistochemistry of the primary lesion and all recurrences showed S-100, HMB-45, NK1/C-3 and Ki-67 positive cells. However, non-malignant cellular blue naevi from five consecutive other patients were all Ki-67 negative. The change from negative to positive Ki-67 responsivity may therefore be a valuable marker of malignant and metastatic potential in early cellular blue naevi.     

Large plaque‐type blue naevus with subcutaneous cellular nodules

We report a new case of ‘large plaque‐type blue naevus (PTBN) with subcutaneous cellular nodules’ involving the breast. A 25‐year‐old‐woman presented with a large plaque, 140 × 100 mm in size, on the right chest wall involving the right breast, associated with recent subcutaneous nodules. Histopathological examination revealed features of cellular and common blue naevus. Dermatoscopy was performed, and the diagnosis of PTBN was made. PTBN is a rare condition with an imprecise prognosis. In cases of PBTN lesions on the head, clinicians must keep in mind the risk of malignant transformation of PTBN or an association with cutaneous neurocristic hamartoma. For this new variant of PTBN appearing on the trunk, we propose close monitoring of the patient if surgical excision is impossible.     

Epithelioid blue naevus of the genital mucosa: report of four cases

Epithelioid blue naevi are an unusual cytological variant of blue naevus that have been recently described mostly in patients with the Carney complex, although they may also occur in isolation. This variant of blue naevus is composed of melanin-laden polygonal epithelioid melanocytes situated within the dermis. The neoplastic cells show no maturation with progressive depth of dermal infiltration and, in contrast with the usual stromal changes in blue naevi, epithelioid blue naevi exhibit no dermal fibrosis. We describe four cases of epithelioid blue naevus located on the genital mucosa in four patients with no evidence of the Carney complex. Three male patients showed an epithelioid blue naevus on the mucosa of the glans penis and a female patient had a lesion of the right labium minoris. Histopathologically, the lesions consisted of entirely intradermal melanocytic naevi composed mostly of heavily pigmented epithelioid melanocytes involving the dermis of the genital mucosa. Immunohistochemically, in all cases, epithelioid melanocytes expressed immunoreactivity for S-100 protein, HMB-45, Melan-A and MiTF antibodies.