Trichoadenoma associated with an intradermal melanocytic nevus: a combined malformation

Melanocytic nevi have been associated with epidermal hyperplasia, adnexal hyperplasia with follicular and sebaceous differentiation, cysts, and tumors of epidermal or adnexal origin. We report a combined cutaneous hamartoma in a 29-year-old woman that comprised a trichoadenoma within an intradermal melanocytic nevus. Clinical diagnosis was a malignant transformation of a melanocytic nevus. Histopathologically, multiple keratinous cysts together with solid islands or masses of eosinophilic epithelial cells were closely intermingled with the nevus cells. Occasional nests of basaloid cells were present. Although to our knowledge this association has not been previously reported, it is worth considering that trichoadenoma and desmoplastic trichoepithelioma are the two ends of a spectrum of lesions. This combined hamartoma reported herein is important because growth of these lesions could be clinically misinterpreted as malignant transformation of a preexisting lesion. Histologic study will reveal the correct diagnosis in such cases.     

Trichoepithelioma associated with cellular blue nevus

BACKGROUND: Epithelial elements, such as trichoepithelioma, are occasionally associated with melanocytic nevi. OBJECTIVE: A case of trichoepithelioma in association with cellular blue nevus is reported. METHODS AND RESULTS: A solitary, pigmented nodule was removed from the scalp of a middle-aged woman. Histopathologic examination demonstrated a circumscribed cellular blue nevus within which were embedded epithelial strands and cystic structures consistent with trichoepithelioma. CONCLUSION: Trichoepitheliomas have been described in relation to common acquired nevi, but an association with a blue nevus is rare. The intimate admixture of trichoepithelioma within the nodule of a nevus supports the concept of epithelial induction by melanocytic nevi.     

A combined case of desmoplastic trichoepithelioma and nevus cell nevus

A 41-year-old woman with desmoplastic trichoepithelioma associated with pigmented nevus presented. Pigmented nevus had been present on her face at birth. She had received cryotherapy and dermabrasion at a small part of the pigmented nevus. As a result of the therapy, the discoloration disappeared. The lesion lately increased and became hard. Histologically, the lesion was composed of two distinctive but intimately mixed cellular components; nevus cells and basaloid cells. In the pigmented lesion, basaloid cells were not present. To our knowledge, this is the first reported case of desmoplastic trichoepithelioma associated with nevocellular nevus in Japan.     

Desmoplastic melanocytic nevi with lymphocytic aggregates

Desmoplastic melanocytic nevi can be difficult to distinguish from desmoplastic melanoma. The presence of lymphocytic aggregates in association with a sclerosing melanocytic proliferation is commonly regarded as a feature in support of a diagnosis of desmoplastic melanoma. However, the finding is not specific for melanoma. Herein we report six cases of sclerosing melanocytic nevi with associated lymphocytic aggregates. They occurred in five women and one man, ranging in age from 11 to 61 years. Three lesions were sclerosing Spitz nevi; one was an amelanotic sclerosing blue nevus, one an acquired intradermal sclerosing nevus, and one was a congenital compound melanocytic nevus with sclerosis of its dermal component. The lesions were interpreted as benign, i.e. melanocytic nevi, because of their histopathologic attributes (symmetric silhouette, benign cytologic features) and results from immunohistochemical studies (all lesions strongly expressed Melan-A and p16) and fluorescence in situ hybridization (FISH). Three lesions tested by FISH lacked copy number changes of 11p, 6q or 6p. None of the lesions recurred. The cases highlight that contextual information is essential for the diagnosis of desmoplastic melanoma and sclerosing nevus. The presence of lymphocytic aggregates per se does not prove that a sclerosing melanocytic proliferation is malignant.     

Desmoplastic trichoepithelioma with nevus cell nevi

Among a total of 270,000 skin biopsies, 87 desmoplastic trichoepitheliomas were identified, 11 (12.6%) of which were associated with nevocytic nevi. Histopathologically we found nevocytes next to horn cysts and thin strands of monomorphous basaloid neoplastic cells in a dense desmoplastic stroma. The frequency of this association suggests that it may be a combined malformation rather than a chance occurrence. On clinical examination most cases had been misdiagnosed as basal cell carcinomas. Most biopsies were taken from the faces of fairly young women.     

Epithelioid blue nevus: neoplasm Sui generis or variation on a theme?

The epithelioid blue nevus has recently been associated with the Carney complex, which is characterized by myxomas, spotty skin pigmentation, endocrine overactivity, and schwannomas. Using the general criteria proposed by Carney and Ferreiro, similar lesions were identified in 33 patients with no evidence of the Carney complex. Those lesions presented on the face, trunk and extremities of 15 males and 18 females. The mean age was 35 years, much older than those in the Carney complex (mean 16.3 years). Clinical diagnoses included malignant blue nevus, atypical nevus, melanoma, congenital nevus, and dermatofibroma. The lesions were symmetric, predominantly dermal melanocytic proliferations arranged as short fascicles, small nests, and single cells. Large polygonal and epithelioid melanocytes with moderate pleomorphism, and occasional nuclear pseudoinclusions were admixed with heavily pigmented dendritic and spindled melanocytes and melanophages. Rare mitotic figures were seen in some cases. The neoplasms showed a morphologic spectrum that encompassed a group of combined blue nevi with epithelioid melanocytes and other Spitz's nevus characteristics. These epithelioid combined nevi (ECN) fell into three phenotypes with morphologies that most closely paralleled those pictured by Carney and Ferreiro in the Carney complex: the classic or Carney complex pattern (ECN-CC), those that showed overlap with deep penetrating nevus (ECN-DPN), and those that have many dermal Spitz's nevus features, [BLue + SpITZ's nevus; (ECN-BLITZ)I. In six cases, there was such an admixture of features that it was difficult to ascribe them to one of the groups. Nine lesions had associated banal congenital nevus. Follow-up that averaged over 2.5 years (31 months) (range 6-162 months) showed no evidence of malignancy or recurrent disease after excision. Epithelioid combined nevus is a type of combined nevus with blue nevus and Spitz's nevus features, which may or may not be associated with the Carney complex. It shows morphologic overlap with the epithelioid blue nevus described by Carney (ECN-CC), deep penetrating nevus (ECN-DPN), and blue nevus with intradermal Spitz's (desmoplastic) nevus (ECN-BLITZ). Epithelioid combined nevus is thought to be a fitting nosologic designation for all of these lesions.     

Unna's and Miescher's nevi: two different types of intradermal nevus: hypothesis concerning their histogenesis

In 1991, we tentatively introduced the classification of Ackerman and Magana-García for acquired melanocytic nevi in our laboratory. We soon realized that every acquired intradermal melanocytic nevus might be easily classified into either Unna's or Miescher's patterns and that this classification had both clinical implications and significant histological differences. The decisive discriminative feature between Unna's and Miescher's nevi is that Unna's nevus is an almost purely adventitial lesion confined to expanded papillary dermis and, many times, to the perifollicular dermis too. In Miescher's nevus melanocytes diffusely infiltrate both adventitial and reticular dermis in a wedge-shaped pattern. With these concepts in mind, every acquired intradermal melanocytic nevus can be easily classified as either Unna's or Miescher's. We studied 751 acquired melanocytic nevi; 458 (61%) of them were intradermal; of these, 234 were Unna's nevi and 224 were Miescher's nevi. Eighty- three per cent of the nevi from the head and neck were intradermal nevi, whereas on the trunk and limbs junction and compound nevi were the most frequent (56%). When intradermal nevi were divided into Unna's and Miescher's patterns, it resulted that 91% of Miescher's nevi located on the face and 94% of intradermal nevi on the face were Miescher's nevi. In contradistinction, 87% of the Unna's nevi located on the neck, trunk, and limbs, and 96% of intradermal nevi from these locations were Unna's nevi. Only on the scalp was there no clear predominance of one type of intradermal nevus. A series of other histological characteristics were significantly predominant (P = 0.000) in either Unna's or Miescher's nevi. Unna's nevi had more: junctional nests above the intradermal component (40% versus 20%), a radial pattern of intradermal nests (38% versus 0%), vascular-like clefts lined by nevus cells (48% versus 4%), and in depth maturation (94% versus 0%). Miescher's nevi had more: pilosebaceous follicles within the nevus (100% versus 51%), subnevis folliculitis (12% versus 1%), large isolated melanocytes along the basal epidermal layer (47% versus 11%), multinucleated nevocytes (89% versus 44%), and adipocytes within the nevus (53% versus 11%). In conclusion, Unna's and Miescher's nevi are 2 subsets of acquired melanocytic nevus with clinical implications and significant histological differences. A histogenetic hypothesis is proposed on the basis of their histological structure.     

Displacement of dermal solar elastosis in malignant melanoma

BACKGROUND: Ultraviolet radiation (UVR) is a major environmental causal factor for skin malignancy. In this study, we investigated the morphology of the solar elastosis (SE) band in benign and malignant melanocytic lesions. METHODS: We measured the SE band in perilesional and lesional skin of 13 melanomas (9 invasive and 4 in situ) and 11 melanocytic nevi (5 usual intradermal nevi, 4 blue nevi and 2 desmoplastic nevi) occurring in sun-exposed areas. RESULTS: The melanoma and nevus groups had similar age range, gender ratio and anatomic distribution. The mean SE thickness was 0.35 mm in melanomas and 0.29 mm in nevi (p = 0.56), indicating similar UVR exposure. There was a mean downward SE displacement (SED) of 0.43 mm in melanomas and essentially no displacement (-0.02 mm) in nevi (p < 0.005). Tumor cells and inflammatory host response were responsible for SED in melanoma. CONCLUSIONS: SED may help in the differential diagnosis of melanocytic lesions in sun-exposed areas. In melanoma, the new lesion depresses the pre-existing SE band. Conversely, the long-standing nevus co-exists with the SE band without significant displacement. Evaluation of the SE band may help to differentiate melanoma with chronic sun-induced damage as they have a distinct set of molecular alterations.     

皮内痣伴结缔组织增生性结节一例

患者男,28岁,因左侧胸部单发褐色肿物4年、多发小丘疹1年就诊。皮肤科检查：胸部左侧一1.2 cm × 1.1 cm × 1.0 cm褐色类圆形肿物,质韧,其右侧数个直径3 ~ 5 mm褐色丘疹,左侧腋下淋巴结未触及肿大。手术完整切除肿物后行组织病理检查：肿物和小丘疹内均可见真皮浅层痣细胞聚集成巢,考虑皮内痣;最大肿物...     

Desmoplastic sebaceoma arising from nevus sebaceus: a new variant

Nevus sebaceus is known to have the potential to develop into various secondary tumors. We observed a sebaceoma arising from a nevus sebaceus excised from the left cheek of a 51‐year‐old woman. This sebaceoma showed desmoplastic change similar to that observed in desmoplastic trichoepithelioma and desmoplastic trichilemmoma. This heretofore undescribed desmoplastic variant of sebaceoma should not be mistaken for invasive sebaceous carcinoma.     

Cerebriform Intradermal Nevus

Abstract: Tumors make up almost 25% of the causes of cutis verticis gyrata. An underlying dermal nevus or neurofibroma is the tumor most often found. Two new cases of cutis verticis gyrata caused by an intradermal nevus cell nevus (cerebriform intradermal nevus) are presented. The importance of early diagnosis and aggressive surgical excision and plastic reconstruction in an attempt to minimize the emotional trauma of the required surgery is stressed. Cerebriform intradermal nevi are a type of large congenital nevi and should be evaluated with this in mind.     

Keratotic Melanocytic Nevus

Thirty-five percent of 363 melanocytic nevi were found to have a keratotic epithelial architectural pattern that was mostly infundibular and not previously emphasized. Keratotic melanocytic nevi were commonly from the trunk of women, and most were associated with an intradermal melanocytic nevus. The clinical and histopathologic features as well as a review of the literature of these keratotic melanocytic nevi are presented.     

Angiomatoid and desmoplastic Spitz nevus presenting as a keloidal nodule

Angiomatoid and desmoplastic Spitz nevi are rare histologic variants of Spitz nevi that present most frequently on the extremities of children and young adults. Although Spitz nevi are clinically heterogeneous, one presenting as a keloidal nodule has not been previously published. We present a case of an angiomatoid and desmoplastic Spitz nevus clinically akin to a keloid on an African‐American teenager and describe its unique histopathologic features.     

Proliferation, apoptosis, and survivin expression in a spectrum of melanocytic nevi

BACKGROUND: Apoptosis is important for maintenance of tissue homeostasis and often dysregulated in cutaneous neoplasms. The apoptosis inhibitor survivin is expressed in melanoma and non-melanoma skin cancers and benign keratinocytic lesions. Its expression has not been studied in melanocytic nevi. OBJECTIVE: We determined the expression pattern of survivin in benign melanocytic nevi in comparison to markers of proliferation and apoptosis. METHODS: Six cases of each of the following melanocytic nevi were retrieved from a dermatopathology archive: compound dysplastic nevus, intradermal nevus, compound nevus, neurotized intradermal nevus, and Spitz nevus. Survivin expression was evaluated by in situ hybridization. Apoptotic and proliferation indices were calculated by counting immunoreactive cells in terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end labeling and proliferating cell nuclear antigen immunostained sections, respectively. RESULTS: All nevi, regardless of histologic type, expressed survivin. Compound melanocytic lesions expressed survivin in both epidermal and dermal compartments. The apoptotic rate was low for dysplastic, compound, and Spitz nevi, and apoptotic cells were not identified in any neurotized nevus. The proliferative index was highest for Spitz nevi, while all other nevi demonstrated rare positive cells. CONCLUSIONS: Survivin is consistently expressed in benign melanocytic lesions, while apoptotic cells are rarely identified, suggesting the dysregulation of apoptotic pathways with the accumulation of cells in these neoplasms.     

Four Cases of Lobulated Intradermal Nevus: A Sign of Aging Melanocytic Nevus

Melanocytic nevi are subject to change with age in both clinical and histopathologic findings. In 1991, Cho et al. first reported three cases of lobulated intradermal nevi and suggested their cases represented an unusual form of regressing melanocytic nevus. Herein we report four cases of lobulated intradermal nevus and review previous literature.     

Cerebriform intradermal nevus: a case of scalp expansion on the galea.

We report here a 7-year-old Japanese girl with cerebriform intradermal nevus (CIN). By placement of expanders on the galea, her scalp was expanded more easily with less discomfort than is expected when the expanders are placed under the galea. An immunohistochemical study on the expression of proliferating cell nuclear antigen suggested higher proliferative activity of nevus cells from the CIN lesion than that of cells from congenital or acquired intradermal nevi. The high proliferative activity appeared to be associated with a growth spurt of the lesion.     

Epithelioid blue nevus: a rare variant of blue nevus not always associated with the Carney complex

Epithelioid blue nevus is a rare variant of blue nevus that has been recently described in patients with Carney complex. Some of the patients with Carney complex have multiple epithelioid blue nevi and a familial history of similar lesions is often recorded. Epithelioid blue nevus consists of an intradermal melanocytic nevus composed of polygonal epithelioid cells laden with melanin. Neoplastic cells show no maturation at the base of the lesion and, in contrast with the usual stromal changes in blue nevi, epithelioid blue nevus exhibits no fibrosis of the dermis. We have studied three cases of epithelioid blue nevus in three patients with no evidence of Carney complex. The lesions were solitary and there was no family history of similar lesions. Therefore, epithelioid blue nevus is a distinctive variant of blue nevus that may also appear as a sporadic lesion and is not always associated with Carney complex.     

Dermoscopic features of combined melanocytic nevi

In order to investigate the possible role of dermoscopy in the non-invasive classification of combined nevi, we analyzed dermoscopic features of a series of combined nevi consecutively excised. Two dermatologists expert in dermoscopy retrospectively evaluated all images based on the presence of dermoscopic findings to analyze which epiluminescence microscopy features were more frequently associated with each type of combined nevus. Dermoscopy may provide useful information in the non-invasive diagnosis of combined nevi, allowing a conservative management, but this may be limited to combined nevi including a blue nevus component. Conversely, combined nevi including a Spitz nevus component may be difficult to classify even by dermoscopy, thus requiring careful monitoring or surgical excision.     

Trichostasis spinulosa within an intradermal melanocytic nevus

A thirty-six-year-old man presented with a melanocytic nevus on his left shoulder. The lesion was excised and histopathologic examination showed an intradermal nevus with several infundibular cysts among the nevus cells. These cysts showed a cyst wall with epidermoid keratinization and a lumen filled by many cross-sectioned hair shafts. These findings were consistent with a diagnosis of trichostasis spinulosa within an intradermal melanocytic nevus. We note the relationship between these two disorders in the same lesion.