Benign atypical junctional melanocytic hyperplasia associated with intradermal nevi: a common finding that may be confused with melanoma in situ.
(1/7)
Over the past few years, consultation cases thought to represent melanoma in situ have been received that consisted of otherwise normal intradermal nevi with an abnormal but benign junctional proliferation of melanocytes that we have termed benign atypical junctional melanocytic hyperplasia. In order to evaluate the incidence of this feature, 400 cases of intradermal nevi were reviewed. Of these, 25 (6.2%) qualified for inclusion, making this a rather common phenomenon. Clinically, patient ages ranged from 18 to 64 years (mean, 35 years), with a male to female ratio of 1:1. Face (40%) and back (32%) were the most common locations. Histologically, the lesions were predominantly dome-shaped with an intradermal component consisting of conventional nevus cells. Most importantly, each lesion exhibited prominent individual nevomelanocytic cells dispersed at uneven intervals along the dermoepidermal junction in insufficient numbers to be considered compound nevi. The cells exhibited abundant pale to clear cytoplasm, an increased nuclear:cytoplasmic ratio, and often exhibited prominent nucleoli. However, these lesions could be distinguished from melanoma in situ by the lack of several features including lateral spread, upward epidermal migration, marked cytologic atypia, finely granular "smoky" melanin pigment, mitotic figures, and a subjacent host inflammatory response. All cases behaved in a benign fashion. Although benign atypical junctional melanocytic hyperplasia is a relatively common histological curiosity, it is a potential pitfall in the diagnosis of pigmented lesions. (+info)
Intradermal melanocytic nevus of the external auditory canal.
(2/7)
Intradermal nevi are common benign pigmented skin tumors. Their occurrence within the external auditory canal is uncommon. The clinical and pathologic features of an intradermal nevus arising within the external auditory canal are presented, and the literature reviewed. (+info)
Cutis verticis gyrata is a rare skin condition characterized by ridges and furrows resembling the surface of the brain. It can be considered as a manifestation of a variety of diverse causes such as cerebriform intradermal nevus. We report a 48-year-old man with cerebriform and soft folds on the left parietal and temporal areas. Histology showed solitary or clusters of nevus cells in the dermis. The diagnosis of cerebriform intradermal nevus was confirmed. (+info)
Porokeratotic eccrine ostial and dermal duct nevus.
(4/7)
Use of histopathology services by general practitioners: recent changes in referral practice.
(6/7)
AIMS: To determine the nature and magnitude of the histopathological workload generated by specimens received from general practitioners and to assess the trends in referral practice. METHODS: All material submitted by general practitioners to the Leicester district histopathology service from 1989 to January 1993 was identified from departmental records. All GP referrals from October to December 1992 were also analysed. Total numbers of referrals from all sources were used for comparison. Specimens were also analysed according to diagnostic categories. RESULTS: There has been a progressive rise, both in the absolute number and the proportion of specimens relative to other surgical specimens submitted by GPs. Most are skin biopsy specimens. There were clear changes over the study period in the relative proportion of different types of lesions received, with a substantial increase in samples of benign naevi and papillomas. There was some evidence of a corresponding decrease in the number of these lesions submitted by hospital practitioners. The number of malignant skin tumours from GPs was small and the proportion had not increased over the study period. CONCLUSIONS: Histopathological workload generated by GPs is increasing but it still represents a small proportion of the total. The major increase is in benign skin lesions. (+info)
Melanoma-associated expression of transforming growth factor-beta isoforms.
(7/7)
Melanocytic neoplasia is characterized by the aberrant overproduction of multiple cytokines in vitro. However, it is largely unknown how cytokine expression relates to melanoma progression in vivo. Transforming growth factor beta (TGF-beta) is a multifunctional cytokine commonly produced by cultured melanoma cells. The in situ expression of all three TGF-beta isoforms (TGF-beta1, -2, and -3) was determined immunohistochemically in melanocytes and in 51 melanocytic lesions using isoform-specific antibodies. Significant linear trends of expression were observed from melanocytes through nevi and primary and metastatic melanomas for all three isoforms. TGF-beta1 was expressed by some melanocytes and almost uniformly by nevi and melanomas. TGF-beta2 and -3 were not expressed in normal melanocytes but were expressed in nevi and early and advanced primary (radial and vertical growth phase) and metastatic melanomas in a tumor-progression-related manner. TGF-beta2 was heterogeneously expressed in advanced primary and metastatic melanomas, whereas TGF-beta3 was uniformly and highly expressed in these lesions. Thus, expression of TGF-beta isoforms in melanocytes and melanocytic lesions is heterogeneous and related to tumor progression, and expression of TGF-beta2 and TGF-beta3 commences at critical junctures during progression of nevi to primary melanomas. (+info)