Melanocytic “ball-in-mitts” and “microalveolar structures” and their role in the development of cellular blue nevi

To test the hypothesis of whether cellular blue nevi (CBN) may originate from "ordinary" compound and dermal nevi, a total of 275 melanocytic nevi including 59 CBN, 34 ordinary blue nevi, 87 combined nevi (including 43 so-called clonal nevi), 35 deep penetrating nevi, and 60 ordinary compound and dermal nevi (30 of each) were studied for the presence of so-called ball-in-mitts and microalveolar structures. A ball-in-mitts structure was defined as a single centrally placed melanocyte with a round to oval nucleus (the "ball" cell) and a clear, dusty, or pigmented cytoplasm encircled by a single dendritic cell (the "mitt" cell) with an oval to spindle-shaped nucleus and slender bipolar processes containing melanin and surrounding at least one fourth of the ball's diameter. A microalveolar structure was defined as a group of 2 to 10 centrally placed melanocytes with round to oval nuclei and clear, dusty, or pigmented cytoplasm (balls) surrounded by one or more cells (mitts) with spindle-shaped nuclei and slender bipolar processes containing melanin. Microscopically, ball-in-mitt and microalveolar structures were detected in all types of nevi studied, with the highest incidence in combined nevi (82%), CBN (76%), and ordinary "nonblue" nevi (73%). In CBN, ball-in-mitts and microalveolar structures tended to be located in the deeper portion of the lesions, whereas in ordinary nonblue nevi, they were most often found superficially, just below the epidermis; in clonal nevi, these structures were often confined to the "clonal" parts. Immunohistochemically, ball-in-mitts and microalveolar structures were positive for HMB45. Ultrastructurally, the balls tended to have round to oval nuclei, whereas the mitts possessed oval, elongated to spindled nuclei. Melanosomes were found in various stages in the cells of both structures. The cytoplasm of the mitts typically formed elongated polar processes, sometimes with club-like widenings at the ends, completely or partially encircling the balls. In the microalveolar structures, the adjacent cells forming the mitts surrounded the ball cells like a chain. Our study suggests that some or even most cases of CBN may evolve from ordinary nonblue nevi. This process may involve several steps and is probably reflected by the appearances of combined nevi, deep penetrating nevi, and CBN. These nevi often show a morphological overlap, and ball-in-mitts and microalveolar structures found in various stages of their development seem to greatly account for this overlap.

Blue nevi of the sinonasal mucosa: a report of two cases and review of the literature

Blue nevi are uncommon melanocytic proliferations. They occur mostly in the skin and occasionally in mucosae. Blue nevi of the sinonasal mucosa are extremely rare with only two cases reported to date. We report two more cases and review the literature. Compared with sinonasal malignant melanomas, which usually present as symptomatic tumors, sinonasal blue nevi are asymptomatic lesions found incidentally. A biopsy is required for a definitive diagnosis. Although none of the four cases had recurrence, given a rare but possible occurrence of malignant transformation in cutaneous blue nevi, complete excision with follow up should be the treatment of choice.

Dermoscopy of a Plantar Combined Blue Nevus: A Simulator of Melanoma

Dermoscopy allows early detection of melanoma also on acral volar skin. The majority of melanocytic nevi on palms and soles may show three major dermoscopic patterns: the parallel-furrow pattern, the lattice-like pattern, and the fibrillar pattern. Melanomas at these sites are characterized by the parallel ridge pattern. We present the case of a 59-year-old woman who had an oval papule of bluish color, measuring 0.6 x 0.9 cm, localized on her left sole, that had been present, unchanged, for more than 10 years. Dermoscopy showed a parallel ridge pattern. The histopathological examination revealed a combined blue nevus. We present this case to underline that on acral volar skin also intradermal nevi, such as combined blue nevi, may dermoscopically exhibit a parallel ridge pattern, simulating melanoma.

Infiltrating giant cellular blue naevus

INTRODUCTION

Cellular blue naevi (CBN) measure 1-2 cm in diameter and affect the dermis, occasionally extending into the subcutaneous fat. The case of a 14-year-old boy with a giant CBN (GCBN) involving the right half of the face, the jugal mucosa and the lower eyelid with a tumour that had infiltrated the bone and the maxillary and ethmoidal sinuses is reported.

METHODS

Biopsies were taken from the skin, jugal mucosa and maxillary sinus. The following markers were used in the immunohistochemical evaluation: CD34, CD56, HMB-45, anti-S100, A-103, Melan A and MIB-1.

RESULTS

The biopsy specimens showed a biphasic pattern affecting the lower dermis, subcutaneous fat, skeletal muscle, bone, jugal mucosa and maxillary sinus, but there was no histological evidence of malignancy. The tumour cells were CD34-, CD56-, HMB45+, anti-S100+ and A-103+. Melan A was focally expressed. No positive MIB-1 cells were identified.

DISCUSSION

The present case shows that GCBN may infiltrate deeply, with no evidence of malignancy.

Malignant Blue Nevus

We report a 55-year-old Japanese patient with a malignant blue nevus (MBN) on the scalp. The patient had regional lymph nodes metastases at his first visit, and a distant cutaneous metastatic papule appeared on the back 1 year later despite therapeutic intervention. Histology of the primary tumor lacked a junctional component and showed a typically biphasic pattern in the degree of pigmentation similar to a cellular blue nevus (BN). One pattern showed nests of less-pigmented, oval-shaped cells with a fairly uniform appearance, and the other pattern showed an aggregation of spindle-shaped cells containing a large amount of melanin pigment intermingled with heavily pigmented melanophages. Histology of metastatic regional lymph nodes also showed a biphasic proliferative pattern of oval-shaped, pale cells and spindle-shaped, richly pigmented cells. A distant cutaneous metastatic papule on the back showed massive proliferation of atypically large, pale, and oval-shaped melanoma cells with heavily pigmented melanophages just beneath the uninvolved epidermis. These histologic features were different from those of metastatic tumor proliferation from conventional melanoma. It seems probable that MBN might maintain a different biological and histopathologic character from conventional melanoma when it grows in metastatic sites.

Blue nevi of internal organs are more similar to the so-called dermal melanocytosis than to cutaneous blue nevi

In this report, we examine several morphologic aspects of blue nevi of internal organs, and compare them to similar conditions of the skin. From a morphologic point of view, blue nevi of internal organs are more similar to the so-called dermal melanocytoses. Nevertheless, since melanocytoses and blue-nevi seem to have the same benign prognosis, and since blue nevus is a historically consolidated term to refer to pigmented spindle cell lesions of internal organs, a most appropriate term, to refer to the latter, will not be easily accepted in literature.

Fine-needle aspiration cytologic diagnosis of metastatic melanotic schwannoma: Familial case of a mother and daughter with Carney's complex and literature review

Carney's complex is an autosomal dominant, multisystem tumorous disorder that includes myxomas, spotty skin pigmentation, endocrine tumors, and peripheral nerve tumors. Psammomatous melanotic schwannomas have recently been included as a part of this complex. Here, we describe the first known familial case of a mother and daughter, both presenting with malignant, already metastatic, pigmented schwannomas initially diagnosed as metastatic melanoma by CT guided fine-needle aspiration. Patients with highly pigmented, extra-cutaneous lesions that are clinically and pathologically suspicious for metastatic malignant melanoma, without known primary tumor, should be evaluated for possible Carney's complex. Additional screening of family members should be recommended to exclude the presence of potentially malignant neoplasms, such as psammomatous melanotic schwannomas.

Blue rubber bleb nevus syndrome co-existing with celiac disease

BACKGROUND

Anaemia caused by iron deficiency is one of the most common disorders in the world. We describe a patient with iron deficiency anaemia in whom absorption was limited due to celiac disease, superimposed to chronic blood loss due to the blue rubber bleb nevus syndrome, a rare syndrome characterised by multiple cutaneous venous malformations in association with visceral lesions.

CASE REPORT

A 54-year-old patient with severe iron deficiency anaemia showed marked rubbery cutaneous lesions on the body surface, extremities, under and on the left side of the tongue as well as in the stomach and duodenum. The appearance and pathological examination of the lesions were consistent with the diagnosis of blue rubber bleb nevus syndrome (BRBNS). Biopsy of the mucosa of the duodenum showed celiac disease. No association between celiac disease and BRBNS has been previously described.

CONCLUSION

Combined loss of iron and malabsorption from the gastrointestinal tract can lead to severe iron deficiency. Early recognition of both diseases can result in early treatment. Patients can recover completely with iron suppletion and a gluten-free diet. Recognising typical BRBNS skin lesions would provide a potential diagnosis and could prevent unnecessary procedures or invasive surgery.

Blue-Rubber-bleb-Naevus-Syndrom und therapeutische Doppel-Ballon-Enteroskopie

This is the first report about the endoscopic removal of hemangiomas in the gastrointestinal tract using the double-balloon enteroscopic technique. We report on a 16-year-old female patient with a 10-year history of chronic anemia due to recurrent gastrointestinal bleeding. Besides permanent iron substitution, up to 3 blood transfusions per week are necessary. At birth a blue rubber-bleb nevus syndrome was diagnosed, with blue angiomatous lesions preferring her skin and digestive tract. In the 8 years before admittance numerous conventional endoscopic procedures and one intraoperative endoscopy with laser coagulation of many cavernous hemangiomas were performed. In our department the successful treatment of 150 hemangiomas with argon plasma coagulation or polypectomy in combination with double-balloon enteroscopy and conventional endoscopy was achieved without complications.

Blue-whitish veil-like structure as the primary dermoscopic feature of combined nevus

The combined nevus is a clinical simulator of melanoma, and clinical examination alone can be inadequate to diagnose this melanocytic pigmented skin lesion. Dermoscopy is a useful tool to differentiate the features related to each type of nevus. We report two cases of combined nevi dermoscopically characterized by a diffuse blue-whitish pigmentation similar to the blue-whitish veil, suggesting the diagnosis of melanoma.

CASE REPORT. 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.

Pigment synthesizing melanoma (so-called animal type melanoma): a clinicopathological study of 14 cases of a poorly known distinctive variant of melanoma

AIMS

Pigment synthesizing melanoma (so-called animal type melanoma) (PSM) is a rare histopathological variant of melanoma so termed because of prominent melanin production and its similarity to a variant of melanoma seen in grey horses. The aim of this study was to report the clinicopathological characteristics of 14 cases of animal type melanoma.

METHODS AND RESULTS

Six patients were female and eight were male with ages ranging from 5 to 52 years (mean 31 years, median 39 years). The head and neck represented the most common site. The clinical diagnosis was of melanoma in seven cases, blue naevus in three cases, benign naevus in three cases and a pigmented basal cell carcinoma in one case. The histological diagnosis of PSM was predicated on the basis of an asymmetrical, predominantly intradermal tumour formed of deeply pigmented, round or short, spindle-shaped dendritic melanocytes with some degree of hyperchromatism and a single nucleolus. Cytological atypia was always present but was not pronounced. A prominent population of macrophages was invariably present. Four tumours were compound and 10 tumours were predominantly intradermal. The mitotic count was usually low, ranging from 1 to 5 per 10 high-power fields (mean 2). Perineural and lymphovascular invasion was not seen. The Breslow thickness ranged from 1.1 to 7.5 mm (mean 3.3 mm). Follow-up was available in 13 patients. The median follow-up period was 5 years. Six patients had no recurrence, three had local recurrence in the form of satellite nodules adjacent to the scar, four had spread to the regional lymph nodes and one patient had distant metastases to the liver. There were no deaths.

CONCLUSIONS

This study demonstrates that PSM is a distinctive, possible low-grade variant of melanoma usually lacking the histological features predictive of aggressive behaviour seen in ordinary melanoma. It should be managed in the same way as other melanomas with wide local excision.

Cutaneous melanoma: uncommon presentations

Melanoma is the most important nonepithelial skin cancer. The diagnosis is usually made by clinical examination including dermatoscopy and histology. There are, however, variants of melanoma that miss the characteristic signs of pigmented lesions which are easily detectable when using the ABCD rule.

Malignant blue nevus of the parotid gland: A case report

BACKGROUND

Malignant blue nevus is a highly aggressive tumor arising from a background of benign blue nevus. Extensive review of the medical literature revealed a few reported cases of this transformation from cutaneous origin. We report the first case of blue nevus of the parotid gland and its malignant transformation within this gland.

METHODS

A 62-year-old woman presented to our clinic with sudden onset parotid mass. After a superficial parotidectomy, histologic examination of the specimen was performed. Features compatible with blue nevus with focal region of atypical mitotic activity were evident. The diagnosis of malignant blue nevus was confirmed by immunohistochemical studies.

RESULTS

We report the first case of malignant transformation of blue nevus within the parotid gland.

CONCLUSIONS

We found this lesion to be highly aggressive and to have metastasized shortly after diagnosis.

Plaque-Type Blue Nevus of the Oral Cavity

BACKGROUND

The blue nevus of the oral cavity is a rare lesion with important differential diagnoses. The plaque-type blue nevus is an uncommon variant of the blue nevus. Because of its particular clinical appearance, it can easily be confused with satellite metastases from malignant melanoma. The diagnosis usually requires a biopsy.

OBJECTIVES

To describe the clinical and histological features of a plaque-type blue nevus of the buccal mucosa in a 20-year-old white woman, to review all intraoral blue nevi and all plaque-type blue nevi reported in the literature so far and to compare the criteria of blue nevi and nevus of Ota.

RESULTS

An intraoral blue nevus was described for the first time in 1959. Since then around 70 further cases have been documented. Our case is the first report of a plaque-type blue nevus of the oral cavity.

CONCLUSIONS

The exceptional widespread intraoral blue nevus described herein can clinically be confused with an intraoral malignant melanoma, and it has a very similar clinical appearance as the intraoral part of nevus of Ota. Apart from the clinical resemblance, there is also some degree of histological overlap of the dermal melanocytoses. Transitional states between blue nevus and nevus of Ota may occur clinically and histologically.