[Melanocytic pseudotumors]. / Melanocytární pseudotumory.

UNLABELLED: Melanocytic lesions are one of the most difficult chapters of dermatopathology when you consider the number of entities, high frequency of excisions and serious consequences of a mistaken diagnosis. Melanocytic pseudotumours, benign lesions simulating melanoma, are its subgroup. At present, it is possible to designate 25 entities and situations. Spitzoid, combined, spindle cell and hyperpigmented lesions belong to the most common problems in the differential diagnosis. Not only histological but also clinical - dynamical and morphological - criteria ought to be taken into account for the maximally correct diagnosis. In heterogeneous lesions it is necessary, although difficult, to try to find the individual components of the lesion in sections. For this reason it is important to know the macroscopy of a particular lesion. In cases where it is impossible to make a reliable decision between benignity and malignancy it is necessary to choose the optimal therapeutic approach in collaboration with a clinical physician. KEYWORDS: melanoma simulators - histology - borderline melanocytic lesions - diagnostic approach.

[Diagnostic pitfalls of HIV-associated Kaposi's sarcoma]. / Uskalí diagnostiky Kaposiho sarkomu sdruzeného s HIV infekcí.

Kaposi's sarcoma was one of the very first diseases which indicated the advent of the AIDS pandemic. Despite the marked fall in its occurrence thanks to the introduction of the cART, Kaposi's sarcoma remains the most frequent tumour in HIV-positive patients and still represents a major diagnostic and therapeutic problem. Particularly in the early stages both the macroscopic and histopathological picture of Kaposi's sarcoma may be very atypical, which can cause diagnostic difficulties right at the time when an early therapy may be most successful. In order to improve both the diagnostics and therapy of Kaposi's sarcoma, close collaboration between physicians taking care of HIV-positive patients--mainly infectologists, dermatologists and pathologists, is necessary.

Segmental Darier's disease postpartum and following tubal ligation.

Segmental Darier's disease is a rare clinical variant of autosomal dominant Darier's disease (keratosis follicularis) exhibiting eruptions in a unilateral arrangement following the lines of Blaschko. It occurs in approximately 10% of patients with Darier's disease. We report two cases of type 1 segmental Darier's disease that appeared a few months after childbirth; in one case, recurrence of the disease occurred after tubal ligation.

[Merkel cell carcinoma--immunohistochemical study in a group of 11 patients]. / Karcinom z Merkelových bunek--imunohistologická studie v souboru 11 pacientu.

The aim of our work was to confirm an immunohistochemical profile of routine markers of epithelial and neuroendocrine differentiation in eleven cases of Merkel cell carcinoma, as well as to study the expression of two markers of early phases of neuronal differentiation, namely reelin and class III beta-tubulin, markers which have not yet been studied in Merkel cell carcinomas. In all the investigated tumours the characteristic "dot-like" pattern of cytokeratin 20 immunoexpression, as well as negative immunostaining for cytokeratin 7 and thyroid transcription factor 1 (TTF-1) were disclosed; all the tumours showed neuroendocrine differentiation, expressing either neuron specific enolase (NSE) or chromogranin A(CgA), or both. An interesting finding was observed when the anti-cytokeratin monoclonal antibody MNF 116 was used. The characteristic "dot-like" pattern was detected in high proportion of tumours, including two samples of local recurrence of one of the carcinomas, where neoplastic cells have lost the expression of cytokeratin 20. The majority (91%) of Merkel cell carcinomas included in our group showed positive immunodetection of class III beta-tubulin when TU-20 antibody was used, while TuJ-1 immunostaining was surprisingly negative in all the investigated tumours. Detection of reelin was negative in almost all the studied Merkel cell carcinomas except for cases, where neoplastic cells revealed weak focal immunostaining in a minor portion of neoplastic cells.

Agminated histiocytomas in a 23-year-old patient.

A 23-year-old patient presented with a group of 17 reddish-brown papules and nodules on the left shoulder lasting for 4 years. The histopathologic examination after a punch biopsy was repetitively consistent with the diagnosis of fibrous histiocytoma (FH). We use the term agminate histiocytomas for the first time to stress the presence of grouped lesions in one skin segment. Intralesional corticosteroids and cryotherapy were partially successful in this patient.

Annular elastolytic giant cell granuloma causes an irreversible disappearance of the elastic fibres.

A 67-year-old man presented with grouped red papules with a smooth surface coalescing to relatively well-demarcated plaques on his left thigh, in the axillae and on the lateral parts of the trunk. The plaques were growing slowly, and the older ones had a frilled surface. A skin biopsy showed a zone of disappearance of the elastic fibres with a rim of giant multinuclear cells with fragments of the elastic fibres in their cytoplasm. This finding is typical of annular elastolytic giant cell granuloma (AEGCG). After corticosteroid therapy, the inflammation resolved, causing the frilled surface of the lesions due to the disappearance of the elastic fibres. Remission of the skin lesions lasted for 1.5 years. A second skin biopsy taken from the site of the previous lesion showed the absence of the elastic fibres, thus their phagocytosis was irreversible.

Verrucous form of chilblain lupus erythematosus.

A 45-year-old woman had symmetrical livid plaques with yellowish hyperkeratoses for 5 years, which progressed on to the fingers and toes and on the soles of the feet. Two years later creamy, whitish areas and maceration appeared on the buccal mucosa and the lips. A skin biopsy revealed massive collagen hyaline degeneration in the perivascular area, hyperkeratosis and hypergranulosis, small lymphocyte infiltrates with several melanophages and extravasates of erythrocytes in the upper corium in perivascular areas and hydropic degeneration of basal keratinocytes. The findings using direct immunofluorescence were compatible with lupus erythematosus (LE). Laboratory investigation showed a slight leucopenia and thrombopenia, a slightly elevated erythrocyte sedimentation rate, hypocomplementaemia C3 and C4, a high titre of rheumatoid factor and antinuclear antibodies positivity of extractable nuclear antigen. The results reflected probably the development of a systemic form of the disease. The patient was successfully managed by methylprednisolone and hydroxychloroquine. After 1 year of therapy, a new skin biopsy revealed a substantial reduction of hyperkeratosis and hyaline degeneration of collagen tissue in the perivascular areas. The combination of the extensive hyperkeratosis and hyalinization thus seems to be features of the long-lasting, untreated lesions in chilblain LE.

Lichen planus pigmentosus-inversus.

We examined seven patients with lichen planus pigmentosus (LPP) clinically and microscopically. Clinically, all patients had a striking predominance of lesions in an intertriginous location, with most of them in the axillae. Microscopically, two biopsies were of significance. Except for the regressive lichen planus, which is usual in LPP, the active inflammatory phase was also present. In these biopsies the very intensive hydropic degeneration of basal keratinocytes was combined with the absence of compensatory increased proliferation of keratinocytes, i.e. without acanthosis. The short duration of this process probably led to the quick transformation into a long noninflammatory regressive phase with incontinence of the pigment. These specific morphogenetic dynamics are possibly why most of the morphs of LPP present as brown, non-pruritic, small inflammatory macules. Because of the highly characteristic inverse location of the lesions in our patients we propose the designation LPP-inversus for this variant of the disease.

[Malignant melanoma in dermatoscopical picture]. / Maligní melanom v dermatoskopickém obrazu (Informacní sdelení).

Dermatological investigation offers a more precise clinical diagnosis of malignant melanoma in 20-30% of cases. It gives a correct visualization of melanocytic structures up to dermatoepidermal junction in ten fold magnification. A less distinct picture can be obtained from medium corial structures. Lentigo maligna melanoma and superficially spreading melanoma can be well distinguished from other pigmented lesions. Dermatoscopy offers an inspirative view between a clinical and microscopical picture plane.

[Cutaneous symptoms in vasculitides]. / Kozní symptomatologie vaskulitid.

Vasculitis has a very variable dermal manifestation. It includes purpura, pustules, bullae, ulcers, nodosits, pomphi etc. Dermal manifestation can represent the initial signs in systemic vasculitis and therefore its early clinical and histopathologic evaluation represents a presupposition for the determination of the subsequent examination route. The study gives information on general morphogenesis, principles of the correctly performed probatory excision, and clinical and histopathologic patterns of individual vasculitis types. (Tab. 2, Ref. 8.).

Systematized progradient multiple combined melanocytic and blue nevus.

A 44-year-old woman was diagnosed as having unilateral multiple progradient pigmented macules and papules of the upper extremity and adjacent part of the back. Microscopically increased amounts of melanin and melanocytes in the basal layer of the epidermis in the early developmental stage of macules were seen. Combinations of blue nevus with junctional or compound nevus or with a simple proliferation of melanocytes in the epidermis were present in the papules. The question of prognosis is discussed.

[The importance of immunofluorescence methods in dermatology]. / Význam imunofluorescencních vysetrovacích metod v dermatologii.

An immediate significance of detection of antibodies by fluorescence distinguish pemphigus, pemphigoid, herpetiform dermatitis and erythematodes. In vasculi-immunohistology was reviewed for diagnostic dermatopahology. Immunohistology helped to tides and lichen ruber planus there were findings more difficult for diagnostis but stimulating.

[Dissimulated dermatozoon delusion with severe skin artifacts]. / Dissimulierter Dermatozoenwahn mit schweren Hautartefakten.

A 37-year-old civil servant, who had been treated for 9 years for sycosis simplex, covered up the presence of his dermatozoon delusion, which had probably only developed in the course of time since the original diagnosis had been made. In a single examination performed when he was referred to our clinic, he admitted for the first time that he had been using sharp objects to dig out ingrown beard hair and mites. This practice had caused numerous sclerotic scars and ulcers on the facial skin. In our dermatological practice, this was an unusual finding in a patient with a dermatozoon delusion.