[Lichen ruber planus after hepatitis B vaccination]. / Lichen ruber planus nach Hepatitis-B-Impfung.

Lichen planus is a T cell mediated papular skin disease. Chronic hepatic disorders, especially chronic hepatitis, have been found to be associated with lichen planus. Recently, it has been recognized that lichen planus can be triggered by hepatitis B vaccination. Here we report on cases of lichen planus triggered by vaccination and review the current literature. Hepatitis B vaccination is being increasingly used and should be considered as a possible trigger of lichen planus.

[Dorsal mucoid cyst--ganglion-like pseudocyst of the joint space]. / Mukoide Dorsalzyste--ganglionartige Pseudozyste des Gelenkspaltes.

A myxoid cyst on the dorsum of the left index finger is presented. A connection of this pseudocyst to the underlying joint was shown by means of magnetic resonance imaging. Surgically the connecting tract to the distal interphalangeal joint was easily demonstrated and histologically a ductal structure was focally seen by means of serial sections. These structures also suggest such a connection. These findings confirm the view that this pseudocyst can be interpreted as a ganglion. Therapeutically complete excision with careful tying off of the channel to the joint appears to be the best method to avoid recurrence. The injection of sclerosing agents, a conservative treatment modality proposed by some authors, may be problematic in the light of the pathogenesis discussed here; however damage to the finger joint has not been so far observed.

Classification of melanocytic nevi: do nodular and flat nevi develop differently?

Previous classifications of melanocytic nevi have not been generally accepted for various reasons. The classification by Ackerman and Magana-Garcia (Am J Dermatopathol 1990;12:193) has also been subject to criticism, even though it is the first taking into account of both clinical and histological aspects of these tumors. To reproduce the findings by Ackerman and Magana-Garcia, the following findings were observed: (a) cases with features of two different types were occasionally seen--33 of 185 cases (17.3%) of nevi of Miescher's and Unna's type showed features of both types and 6 of 205 (3%) flat nevi had a slight to pronounced papillomatous surface--(b) contrary to Unna's theory of "Abtropfung," no junctional nevi of Unna's and Miescher's type and no dermal nevi of cases with a flat configuration were seen. It is concluded that the main differences among melanocytic nevi were seen between flat and nodular nevi, showing (a) different clinical configurations (b) different histological features, (c) possibly a different histogenesis, and (d) different malignant potentials.

[Epithelioid cell histiocytoma]. / Das epitheloidzellige Histiozytom.

We report on seven examples of this rare, only recently described benign tumor, which presented clinically as solitary elevated nodules on the lower (n = 5) and upper (n = 2) extremity, measuring between 0.6 and 1.1 cm in diameter. Histologically, all tumors were well-defined with a characteristic epidermal collarette. There were abundant (60-80%) epithelioid cells with prominent cytoplasm, a vesicular nucleus and inconspicuous nucleolus, as well as a number of dilated blood vessels. Immunohistologically, tumor cells did not react with monocyte/macrophage antibodies (KP1, MAC387). In addition, there was no evidence of myofibroblastic differentiation (alpha-smooth muscle actin and desmin negative). Thus, while immunohistological markers are helpful to exclude the diagnosis of other tumors, they do not shed light on the differentiation of epithelioid cell histiocytomas. The present cases are identical to those described originally. Recently similar lesions have been described in deeper parts of the corium as well as more cellular forms. Epithelioid cell histiocytoma represents a characteristic, poorly known variant within the spectrum of benign fibrous histiocytomas; it needs to be distinguished clinically and histopathologically especially from Spitz nevus.

Melanocytic hyperplasia in scars. A histopathological investigation of 722 cases.

We studied 722 reexcision scars of benign and malignant lesions (except melanocytic lesions) excised over a 24-month period. The formalin-fixed, paraffin-embedded tissue sections were examined histologically and immunohistochemically. The histological features of melanocytic hyperplasia were present in 59 cases (8%), 56 from the sun-exposed skin of the face and neck and three from the trunk [p < 0.00001]. The most common sites were the nose and lower eyelids, but the forehead was also frequently involved. Of the 59 patients, 41 were women (p < 0.0001). Basal cell carcinoma was the most frequent original lesion in both sexes (80%). No melanocytic hyperplasia was found in 663 cases (298 on the trunk and extremities and 365 on the head and neck). We have seen this reaction pattern following reexcision of melanocytic lesions as well. Thus, interpreting reexcision margins when lentigo maligna or similar lesions are reexcised may be fraught with difficulty. It is important for pathologists and dermatopathologists to recognize this phenomenon because histologically the presence of increased numbers of large melanocytes could be misinterpreted as melanoma in situ.

Multivariate DNA cytometry discriminates between Spitz nevi and malignant melanomas because large polymorphic nuclei in Spitz nevi are not aneuploid.

To elucidate the reasons for the malignant histologic appearance of melanocytic nuclei within benign Spitz nevi (SN), we evaluated nuclear DNA distribution and nuclear size using a computerized image analysis system. In each case of 28 SN and 34 malignant melanomas (MM), about 100 randomly sampled nuclei were analyzed, prepared as monolayers from paraffin-embedded tissues. Large nuclei in MM (nuclear area > mean nuclear area of normal melanocytes + 4 delta) were significantly more likely to be aneuploid (DNA content > or = 5c) than large nuclei in SN chi2 test, p < 0.0001). Only two of 990 large SN nuclei exhibited DNA values higher than 5c, whereas 236 of 2,024 large MM nuclei were aneuploid or polyploid. Accordingly, in multivariate analysis, five features of DNA distribution proved to be most important for objective discrimination between MM and SN: 2c deviation index, 5c exceeding rate, standard deviation of the nuclear DNA content, and both the 85th and the 95th percentiles of DNA distributions. On the basis of these features, we could define a linear discriminant function that allowed a correct diagnosis in 94% of the cases. Our data demonstrate that diagnostically misleading large nuclei in SN are euploid, in contrast to MM. It is thus possible to discriminate SN and MM with high accuracy using DNA cytometry. Because paraffin-embedded tissue can be used, this technique could be a valuable complement to routine histology in equivocal cases.

Cutaneous angiomyxoma: a benign neoplasm distinct from cutaneous focal mucinosis.

We describe a cutaneous angiomyxoma on the head of a 38-year-old man without evidence of Carney's complex. Complete excision of the tumor appeared to be curative. Histologic examination revealed fibroblast-like cells embedded in a well-demarcated, lobulate, mucinous, and vascularized stroma with a delicate reticulin network. Immunohistologically, the stromal cells were consistently positive for vimentin and focally positive for smooth muscle A-actin but were negative for desmin, KP1, MAC387, factor XIIIa, CD34, Leu-7, and S-100. Cutaneous angiomyxoma appears to represent a myofibroblastic neoplasm that should be distinguished from cutaneous focal mucinosis.

Cutaneous focal mucinosis--a histopathological and immunohistochemical analysis of 11 cases.

The histogenesis of cutaneous focal mucinosis (CFM) is controversial. Eleven cases of CFM (5F, 6M; mean age 51 years) from our routine files between 1986 and the present time have, therefore, been examined histopathologically and immunohistochemically. Histology revealed an increased number of fibroblast-like cells in early lesions, whereas they were diminished or predominantly at the margin in advanced ones. The myxomatous areas showed slight to absent reticulum formation. Similarly, elastic fibers were almost absent, and collagen fibers were fragmented and replaced by variable amounts of mucin. One specimen revealed an epithelial component within the lesion reminiscent of a poorly induced trichofolliculoma. Immunohistochemically, vimentin was consistently present and correlated with the number of fibroblast-like cells. A few (< 5%) CD34+ dermal dendritic cells (DDs) were focally seen within CFM. In contrast, FXIIIa+ DDs accounted for up to 30%. Fibroblast-like cells were negative for S-100 protein, Leu7, desmin and alpha-SMA. The epithelial component within one of our specimens seems to have been induced by CFM and is a feature also seen in (angio)-myxomas. CFM appears to be a mesenchymally derived lesion composed predominantly of fibroblasts. DDs do not form the major cell component but rather seem passively incorporated.

[Microfilm documentation in follow-up of melanocytic tumors]. / Mikrofilmdokumentation in der Verlaufskontrolle von melanozytären Tumoren.

Microfilm photography allows documentation of naevi in a map-like fashion. The localization of multiple naevi is no longer a problem, as one can scan the film. Comparison of the magnified film with the patient can be done in day-light. Magnification up to 48 times is possible. Detection of early changes of the naevi, during the horizontal growth phase, should increase the 5-year survival rate.

[Argon laser therapy of chondrodermatitis nodularis chronica helicis]. / Argonlasertherapie der Chondrodermatitis nodularis chronica helicis.

In 5 years 9 patients with a total of 16 painful ear nodules (chondrodermatitis helicis) have been treated as follows. A small excision is carried out with local anaesthesia for histological examination. The rest of the nodule or any other nodules are carbonized by means of the argon laser, also with local anaesthesia, including the surface of the cartilage under the nodules. There have been no cases of postoperative inflammation or infection. New nodules occurring several months after treatment have been successfully treated in the same way. There have been no real recurrences. The cosmetic result is very good in all cases. The patients are free of pain immediately after the laser therapy. Laser therapy for painful nodules of the ear has good and lasting results, with a lower rate of recurrences than any other form of treatment.

[Lichen ruber hypertrophicus with verrucous carcinoma]. / Lichen ruber hypertrophicus mit verrukösem Karzinom.

A 51-year-old patient presented with aggregated papules and with a central, partly erosive plaque on the left lower leg. Histological examination revealed hypertrophic lichen planus peripherally and a verrucous carcinoma within the centre. The lesion was removed surgically. Shortly after wards an atrophic lichen planus developed exclusively within the skin graft, which was effectively treated with topical steroid cream. The patient remained disease-free for 2 years. The literature relating to malignant transformation of cutaneous lichen planus was reviewed. In most cases, as in the present one, the hypertrophic form of lichen planus and the verrucous type of carcinoma (Ackerman) are reported. Recent investigations have revealed human papilloma virus types 6 and 11 within such lesions.

Myoepithelial differentiation in benign sweat gland tumors. Demonstrated by a monoclonal antibody to alpha-smooth muscle actin.

One hundred and two cases of benign sweat gland tumors of the skin were studied for the presence of myoepithelial cells specifically identified by a monoclonal antibody to alpha-smooth muscle actin on paraffin-embedded tissues. The monoclonal antibody gave a positive result in 12 of 12 cases of cylindroma, 14 of 16 cases of spiradenoma, 2 of 2 cases of apocrine tubular adenoma (papillary eccrine adenoma), 5 of 5 cases of apocrine hidrocystoma, 5 of 5 cases of hidradenoma papilliferum, and in 10 of 10 cases of syringocystadenoma papilliferum. Rare myoepithelial cells were detected in only 1 of 10 cases of mixed tumor, apocrine type. There was no immunoreactivity for alpha-smooth muscle actin in eccrine hidrocystoma (2 cases), mixed tumor of eccrine type (2 cases), syringoma (7 cases), hidroacanthoma simplex (1 case), eccrine poroma (14 cases), clear cell hidradenoma (15 cases), and in 1 case of eccrine syringofibroadenoma. Our data support the concept that myoepithelial cells are seen in most sweat gland tumors considered to differentiate toward the secretory coil of the normal sweat gland. In contrast, myoepithelial cells are absent in tumors showing differentiation toward the excretory (ductal) component of the gland.

Inflammatory cellular infiltrates in melanocytic nevi.

We examined 1,054 melanocytic nevi [137 (13%) simple lentigines, 158 (15%) junctional nevi, 337 (32%) compound nevi, and 422 (40%) dermal nevi] for the presence of lymphohistiocytic infiltrates. The following criteria were evaluated: age and sex of the patient, location, histological type, horizontal and vertical diameter, increase of melanocytes in the basal layer of the epidermis, increase of melanophages in the papillary dermis, melanin content of keratinocytes, and melanin content of nevus cells. Lymphohistiocytic infiltrates were measured semiquantitatively; their presence within the center, in the lateral margins, or both was also determined. The results were analyzed statistically by means of chi-square tests and univariate and multivariate analyses. We found that 824 lesions (78%) were associated with a lymphohistiocytic infiltrate; whereas 230 (22%) were not. This infiltrate was weak in 273 cases (33%), moderate in 411 cases (50%), pronounced in 130 cases (16%), and very strong in 10 cases (1%). Multivariate analyses revealed that the only criteria associated with the presence of lymphohistiocytic infiltrates were the increase of melanocytes in the basal layer and the vertical thickness in compound nevi. All other parameters were statistically insignificant. We conclude that melanocytic nevi with a junctional hyperplasia of melanocytes--i.e., mostly early stages such as simple lentigines, junctional nevi, and superficial compound nevi--are often associated with a moderate to pronounced cellular stromal reaction. Their presence may reflect the appearance of antigens on proliferating melanocytes. It may also represent a stromal reaction to necrotic tumor cells and keratinocytes within the dermoepidermal junction. These findings rule out any relationship to an increase of melanin pigment.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrastructural discrimination between malignant melanomas and benign nevocytic nevi using high-resolution image and multivariate analyses.

Prompted by the well-known difficulties of reliable and objective histologic differentiation between initial malignant melanoma (MM) and benign nevocytic nevi (NN), ultrastructural high-resolution image and multivariate analyses were evaluated for their diagnostic efficiency. Thirty-seven different features describing morphometry (area, circumference, and shape factor), amount of heterochromatin and euchromatin, chromatin homogeneity, and presence of smaller dark chromatin aggregations were determined by a MICROVAX 3500 computer in each of 1840 intraepidermal melanocytic nuclei of 17 MM and 20 NN. A strategy for the classification of cases based on the identification of markedly atypical melanocytic cells (MACS) was developed. MACS, selected in multivariate analysis with a linear combination of the eight most important features for cell classification, were found in 39.4% of the melanoma cells, but only in 0.3% of nevocytic nevus cells. The presence of MACS allowed a clear differentiation between MM and NN. All cases of MM had more than four MACS, whereas 17 cases of nevocytic nevi were MACS negative, and in each of the remaining three cases only one MAC was present. The percentage of MACS detected within intraepidermal parts of MM by using computerized high-resolution image analysis was found to be a highly efficient diagnostic marker. The new classification strategy has the potential of saving considerable time in subsequent studies, because preselected sampling and the calculation of only a few criteria have proven sufficient for correct classification of malignant melanomas.

[Encapsulated neuroma of the skin. A clinical, histologic and immunohistologic study]. / Das umkapselte Neurom der Haut. Eine klinische, histologische und immunhistologische Studie.

Encapsulated neuroma of the skin is a little known, though not especially rare, benign tumour of the peripheral nerve system. It is often wrongly diagnosed on the basis of both clinical and histological investigation. We have subjected 24 encapsulated neuromas to clinical, histological, and immunohistological study. Clinically, they presented as solitary, skin-coloured small nodules, usually located on the face in middle-aged adults. Histologically, encapsulated neuromas are well-circumscribed dermal tumours. They are composed of interlacing fascicles of Schwann cells (S-100 protein +) and numerous tiny axons (S-100 protein +, neurofilament +). Most reveal at least partial encapsulation with perineurial differentiation (EMA +, vimentin +). Encapsulated neuromas can be differentiated from other tumours of the peripheral nerve system and from leiomyoma by their distinctive histological and immunohistological features.

Identification of basement membrane components in eosinophilic globules in a case of Spitz's nevus.

A case of Spitz's nevus with eosinophilic globules was examined using antibodies for several components of the basement membrane. Aggregated tumor cells revealed the same characteristics as normal nevocytic nevi, that is, they were surrounded by laminin and type-IV collagen, whereas type-VII collagen was absent. All of these components of basement membranes, including type-VII collagen, were also found in eosinophilic globules, which were densely stained by these antibodies. It is assumed that these eosinophilic globules are essentially composed of basement membrane components, which are probably synthesized by epidermal and possibly also by melanocytic tumor cells.