Complete regression of primary cutaneous malignant melanoma associated with distant lymph node metastasis: a teaching case mimicking blue nevus

BACKGROUND

Malignant melanoma (MM) tends to be spontaneously regressed, however, complete regression of primary cutaneous MM is an extremely rare phenomenon. Our aim is to be aware that pathologists and/or dermatologists can readily misinterpret it as the other benign or malignant lesions.

CASE PRESENTATION

A gradually growing and verrucous hypopigmented macule had been noticed in the right sole of a 65-year-old Japanese male since 2 years before, and it turned to be a solitary bluish to black patch with surrounding depigmentation and was recently decreased in size. In parallel, the patient had a rapidly growing black-pigmented mass lesion at the right inguen. The cutaneous specimen from the sole showed an aggregation of many melanophages predominantly in the middle to deep layer of dermis, associated with surrounding fibrosis, reactive vascular proliferation and CD8-positive T-lymphocytic infiltrate, covered by attenuated epidermis with absence of rete ridge. However, no remnant MM cells were completely seen in the step-serial sections. We first interpreted it as blue nevus. By contrast, the inguinal mass revealed a diffuse proliferation of highly atypical mono- to multi-nucleated large cells having abundant eosinophilic cytoplasm in the enlarged lymph node tissue. Immunohistochemical findings demonstrated that these atypical cells were specifically positive for HMB45 and Melan A. Therefore, we finally made a diagnosis of complete regression of primary cutaneous MM associated with distant lymph node metastasis of MM.

CONCLUSION

Careful, not only general/cutaneous but histopathological, examinations should be necessary and adjunctive aids for reaching the correct diagnosis of complete regression of cutaneous MM.

Agminated Blue Nevus: Two Case Reports and a Mini-review of the Literature

Agminated blue nevus (ABN) is a melanocytic nevus rarely mentioned in the literature and not well known. The term agminated is used when many blue nevi are clustered together in a sharply demarcated area ≤10 cm. Specific dermatoscopic features have not currently been clearly defined. We describe two cases of ABN and provide a review of the literature, reporting the main points in order to facilitate the diagnosis of this rare entity.

Giant Blue Nevus: A New Association to Nevus of Ota

Nevus of Ota, also known as oculodermal melanocytosis, is a congenital pigmentary condition that can affect structures in the distribution of the ophthalmic and maxillary divisions of the trigeminal cranial nerve. Malignant transformation, although rare, may occur within nevus of Ota and result in uveal, cutaneous, orbital or even dural melanoma. We present a new association of Nevus of Ota complicated with a giant orbital Blue Nevus in a young white male and the management of this tumor.

[Utility of skin ultrasound in the differential diagnosis of blue lesions, hydrocysts]

Many skin diseases may present as blue papules and nodules; the differential diagnosis includes such different entities such as metastatic melanoma, angioma, lipoma, epidermoid cyst, pilomatrixoma, blue nevus, glomus tumor, or hidrocystoma. Cutaneous ultrasound can be a complementary diagnostic technique of great value in these cases.

Blue Rubber-Bleb Nevus Syndrome: Report of a Case Associated with Osteoid Osteomas

Blue rubber-bleb nevus syndrome (BRBNS), or Bean's syndrome, is a rare angiomatosis characterized by multiple cavernous hemangiomas of the skin, mucosae and frequently of other sites. A 49-year-old male patient had been affected since birth by multiple angiomas localized in the skin, lips, oral cavity, cranial theca, and central nervous system; intrauterine rupture of angiomas in the right parietal lobe had caused partial hypotrophic paralysis of the left hemisoma. In addition to BRBNS, the patient was affected by three osteoid osteomas: this never-described clinical association is here discussed.

Malignant blue nevus: clinicopathologically similar to melanoma

Malignant blue nevus (MBN) is a rare melanocytic lesion and controversy exists whether it is a melanoma or a unique entity. We sought to establish clinical behavior using a large national registry. All patients with MBN and melanoma from 1973 to 2008 were identified in the Surveillance Epidemiology and End Results tumor registry. We performed comparative and survival analysis among the two tumor types. A total of 228,038 patients were identified (227,986 with melanoma and 52 with MBN). The mean age was 57.7 years. Both lesions had similar age of presentation (55.8 vs 55.7 years, P = 0.527), sex (male 50 vs 55%, P = 0.44), and nodal positivity rate (9.6 vs 5.4%, P = 0.22). MBNs were more likely to be nonwhite (11.8 vs 1.6%, P < 0.0001) and present with metastatic disease (15.2 vs 4%, P = 0.0028). MBN and melanoma had a similar survival (264 vs 240 months, P = 0.78) and remained similar when stratified by race (264 vs 242 months, P = 0.99) and stage (264 vs 256 months, P = 0.83). This is the largest study to date demonstrating similar clinical behavior and survival between patients with MBN and those with melanoma. We believe MBN is a variant of melanoma and suggest using a similar treatment algorithm as that of melanoma.

Unusual variant of blue nevus associated with dermatofibromas

The blue nevus is a variant of a melanocytic nevus that presents as blue-gray to blue or black papules or nodules measuring up to 1 cm in diameter; it has a predilection for females and can be congenital or acquired. The classification of blue nevi is complex, with biological behavior being benign, borderline, or malignant. The case we present is one of a 40-year-old woman with multiple dermatofibromas that appeared and increased gradually in size during pregnancy. Physical examination revealed three spherical, brownish to red-purple nodules localized on the left leg, right shoulder and right laterocervical area. In addition, on her right forearm, there was a 0.3 cm nodule with a discreet non-pigmented, elevated area and a blue perilesional border that appeared in her childhood, affirmative after stinging herself with a pencil. The patient's family history was negative for significant lesions. The laboratory and imagistic findings were normal. Four skin biopsies were performed. The histopathological examination revealed an uncommon blue nevus with two different populations of pigmented cells: spindle shaped or dendritic melanocytes diffuse distributed in the middle dermis and closely aggregated deeply pigmented melanocytes in the reticular dermis. The other three lesions were diagnosed as dermatofibromas: bland spindle shaped cells in a fibrous stroma, some cells with a storiform arrangement. The overlying epidermis was hyperplastic with acanthosis and hyperpigmentation of the basal cell layer. No mitoses were seen.

Dermoscopic features of common nevi: a review

The differentiation between benign and worrisome melanocytic lesions may be challenging in the absence of the glaringly obvious clinical features that define a cutaneous malignancy. In such situations, dermoscopy may prove useful in further defining characteristics that are more indicative of a benign lesion, which can ultimately help avoid an unnecessary biopsy. Recognizing of the dermoscopic findings of benign nevi, taking into consideration the predominant pigment pattern and its organization, may aid in the evaluation of pigmented lesions. Benign nevi tend to exhibit symmetry, regularity in shape, and uniformity of dermoscopic structures. This article reviews the clinical and dermoscopic features of common acquired nevi (dermal, compound, and junctional), blue nevi, and congenital nevi.

Benign blue naevus of the lungs

Blue naevus is a dark blue, gray or black lesion consisted of dermal melanocytes and usually found on face, scalp, or on the dorsum of hands and feet. Two well defined histologic and clinical variants, designated as "common" and "cellular", have been recognised. An unusual case of accidentally detected common blue naevus of the lungs has been reported. The specimen of lung tissue was taken during autopsy of a 62-year old woman who died of myocardial infarction. Microscopic analysis revealed the area containing melanocytes filled with melanin pigment.

Skull base tumor in a patient with phacomatosis pigmentovascularis

A 58-year-old man with clinical diagnosis of phacomatosis pigmentovascularis (PPV) experienced tinnitus and progressive hearing loss due to a jugular foramen tumor.Attached to the tumor capsule, were several pigmented spots. Pathological examination revealed a tumor composed by two different tissues, namely a Schwannoma grade I associated with a leptomeningeal blue nevus. The neuropathological aspects of this unusual association are discussed. The association of PPV with a pigmented skull base tumor has not been described to date and illustrates the importance of systemic examination in PPV.

Blue nevus of the prostate: incidental finding in radical prostatectomy specimen with a pre-operative echographic image of peripheral hypoechogenic nodule

Blue nevus is a stromal melanin deposition, which is microscopically characterized by deeply pigmented melanin-filled spindle cells within the fibromuscular stroma. Cases with prominent melanosis such as those with grossly visible pigment are uncommon. Melanocytic lesions of the prostate are incidental findings with no evidence of malignant transformation. There have only been very few reports of a malignant melanoma of primary prostatic origin. We report an incidental finding of a blue nevus of the prostate, in a radical prostatectomy specimen, in a 64-years-old man with a pre-operative ecographic image of peripheral hypoechogenic nodule. The are very few reports of blue nevi associated to prostatic adenocarcinoma, but none has been evidentiated before surgery as a distinct ultrasound lesion interpreted as adenocarcinoma, therefore inducing the clinician to perform biopsies and consequently a radical prostatectomy.

Cervical cystic lymphangioma in a patient with blue rubber bleb nevus syndrome: clinical case report and review of the literature

We present the case of a 9-year-old boy diagnosed with blue rubber bleb nevus syndrome, who showed a very large left cervical cystic lymphangioma. He was previously subjected to various treatments for lesions in the intestinal tract including blood transfusions for anemia, sclerosis, enterotomies or resections. The tumor was resected without any complications and the anatomopathologic report confirmed this diagnosis. The blue cavernous hemangioma syndrome (or blue rubber bleb nevus syndrome) is a rare disease characterized by cavernous angiomas involving the skin and gastrointestinal tract. Several cases of cystic lymphangiomas associated with this syndrome have been published recently and lymphomatous differentiation has been identified in the cells of cutaneous lesions. Given their common embryological origin, we underscore the importance of bearing in mind that it is possible for different types of vascular malformations to coexist in the same patient.