ABSTRACT
Blue nevi can present clinically as blue, gray, brown, or black solitary nodules or plaques on the skin. Histologically, they represent collections of melanocytes and melanophages in the dermis. We presented here a case of a cellular blue nevus in a 20 years old man that presented as an enlarging blue-gray nodule on the right buttock. These cases can be challenging both clinically and histologically because malignant melanoma or malignant transformation of a blue nevus could be considered.
ABSTRACT
We experienced an unusual case of the cellular nevus on the dorsal surface of the second metacarpophalangeal joint. We performed a local excision followed by immunohistochemical analysis. Cellular blue nevus should be considered in the differential diagnosis when a characteristic blue-black mass is found in the finger. Accurate diagnosis based on immunohistochemical analysis, appropriate surgical treatment and vigilant follow-up are mandatory to prevent any malignant transformation.
Subject(s)
Diagnosis, Differential , Fingers , Follow-Up Studies , Melanoma , Metacarpophalangeal Joint , Nevus , Nevus, BlueABSTRACT
Cellular blue nevus is a rare type of blue nevus, which shows blue-gray or blue brown nodules or plaques of 1 to 3cm in diameter, usually located on the buttocks or sacrum. We report a case of cellular blue nevus in a 42-year-old female. She presented with a 1x3.5cm blue-black multilobulated plaque on the dorsum of left foot since childhood. Histopathologic examination showed mixed biphasic pattern with ovoid islands of polygonal cells showing somewhat clear cytoplasm alternating with bundles with spindle cells, which are densely pigmented. Mitosis and necrosis were not identified. Overall features are consistent with cellular blue nevus.
Subject(s)
Adult , Female , Humans , Buttocks , Cytoplasm , Foot , Islands , Mitosis , Necrosis , Nevus, Blue , SacrumABSTRACT
Blue nevus is a benign pigmented lesion of dermal melanocytes with a number of histologic and clinical variants. We report a variant of cellular blue nevus that is minimally pigmented. Immunohistochemistry showed the case to be strongly positive with S-100 protein, but negative with Ki-67 and HMB-45 antibody. There is a potential for hypopigmented cellular blue nevus to be confused with other benign nevus, such as intradermal nevus, Spitz nevus, and deep penetrating nevus and malignant melanoma.
Subject(s)
Immunohistochemistry , Melanocytes , Melanoma , Nevus , Nevus, Blue , Nevus, Epithelioid and Spindle Cell , Nevus, Intradermal , S100 ProteinsABSTRACT
Cellular blue nevus is an benign variant of blue nevus group, characterized by cellular islands composed of closely aggregated spindle cells with little or no melanin. The other variants include atypical and malignant blue nevus which often had the difficulties in the differential diagnosis from the malignant melanoma. A 4-year-old boy presented with hemispheric scalp nodule, which has been slowly grown since birth, measuring 3.5x3x1.5 cm. The surface showed geographic black pigmentation without hairs, hemorrhage, and ulceration. The excised mass disclosed homogeneoulsy dark black, glistening, and muddy cut surface. Histological examination revealed exuberant melanocytic proliferation with both spindle and dendritic components. Heavily pigment ed spindle cells, melanophages, focal necrosis, and vacuolated epithelioid cells were unusually noted in our case and diagnosed as cellular blue nevus. Electron microscopy disclosed largely mature melanosomes in tumor cells and melanophages. During about 16 months since operation, he has been relatively well with no evidence of disease.
Subject(s)
Diagnosis, DifferentialABSTRACT
A 34-year-old female had an unusual case of cellular blue nevus which had behaved in a locally aggressive fashion. The lesion infiltrsted the adjacent soft tissue of left nail bed and extended into deep phalangeal bone. The involved left thumb was partially amputated because complete excision was impossible and we were quite concerned about malignant transformation. Histologically biphasic pattern without cellular atypism, a characteristic features of cellular blue nevus, was shown. About 2 years later, the lesion had not recurred.