Porphyrias

sso

Course

CS. Phorodermatoses

reagents is more focussed on organic sunscreen agents. While expanding use in cosmetics and even bath products might suggest an increase in photoallergy, there is no objective evidence for this.

B-2 El

Polymorphic light eruption and hydroa vacciniformia

Martin R&ken, Nikola Salomon, Monika Walchner. Department of Dermatolog)\ Lud,vi~-M~i~~~ilia~ts-U~~il~ersi~ Munich, Frauenlobst.9-I I, 80337 Munich, Germany

Sunlight may provoke a large spectrum of diseases. They may be divided into photosensitive disorders secondary to known photosensitizing agents and ‘genuine’ photosensitivity, of unknown origin, such as polymorphic light eruption (PLE). lupus erythematousus (LE) or hydroa vacciniformia. Provocation of these diseases with artificial UV-irradiation devices showed that they are predominantly caused by UVA. However, 20-30% of the patients with PLE or LE may also be provoked by UVB: Standardized experimental photo-provocation has become a valuable diagnostic tool. Most importantly, standardized photoprovocation not only allows the exact diagnosis and an exact determination of the UV-spectrum resposible for the disease, but also to test the efficacy of sun screens and therapies such as PUVA or UVB 311 nm. This is especially important as no standards exists to describe the ‘sun protection factor’ of UVA. Our recent data revealed that photoprovocation of PLE in the presence of UV-protective sunscreens reliably allows to predict their protective value to sunlight.

IE-3

Actinic prurigo and solar urticaria

E. HSlzle. Department Oldenburg,

Oldenburg,

of Dermatology, Germany

City Hospital

Actinic prurigo is a rare idiopathic photodermatosis, which shares some features with atopic dermatitis, polymorphous light eruption, hydroa vacciniforme and persistent light reaction. Among Amercian Indians familial variant is observed, which has also been termed hereditary polymorpous light eruption in American Indians. Characteristic features of actinic prurigo are a chronic course with sustained exacerbations, seasonally in the beginning and later perennial. The disorder may improve in adulthood. The typical clinical features comprise immediate urticarial plaques and persistent eczematous or prurigo-like rash mainly in light-exposed areas. Therapy is extremely difficult and unrewarding. Solar urticaria is characterized by immediate erythema and whealing after exposure to small amounts of UV-radiation. Action spectra vary among patients. In addition, photoinhibition and photoaugmentation are obsorved. In some patients the putative photoallergen is found in serum or plasma. Development of transient skin tolerance by repeated exposures provides one therapeutic approach, which achieves a short-lasting relief. Long-lasting improvement results from PUVA-therapy or, if a serum factor is discernible, from plasmapheresis. Recently both regimens have been combined and led to complete remissions.

I05-5

Photoaggravated

H. HSnigsmann. Division Dermatology,

University

diseases

of Special of Vienna,

& Environmental Vienna, Austria

Photoaggravated dermatoses (UV exacerbated skin disorders) represent a very heterogeneous group of dermatoses. By definition these diseases can be adversely affected by exposure to sunlight or to therapeutic or cosmetic UV irradiation. They are not true photodermatoses since they develop without exposure to radiation. The precise underlying mechanisms are mostly undetermined. In some disorders sunlight specifically contributes to the pathogenesis (e.g. subcutaneous lupus erythematosus) in others, radiation represents just one of several possible factors that may precipitate the disease. Photoaggravated skin disorders are of diverse or unknown aetiology and photoaggravation occurs only in some but not in all of the affected individuals. In many instances the role of light is clearly defined, however in others documentation of light sensitivity is poor. Some of the clinically most relevant conditions are discussed in this presentation. (List of diseases: Atopic dermatitis, Lichen planus, Photosensitive psoriasis, Lupus erythematosus, Darier’s disease, Bullous pemphigoid, Hailey-Hailey disease, Pemphigus, Herpes simplex, Transient acantholytic dermatosis. Erythema multiforme, Pellagra) I C5-6 Porphyrias M. Lecha, C. Herrero. Dermatologia, Barcelona,

Hospital

Clinic,

Spain

Poprhyrias are a group of diseases caused by partial enzyme deficiencies in the biosynthetic pathway of haem. These enzyme deficiencies are hereditary except for the most frequent type I porphyria cutanea tarda, usually an acquired disease. Accumulation of intermediate metabolites in the biosynthetic pathway -the porphyrins- is produced and clinical manifestations ensue. Eight enzymes act sequentially to produce the synthesis of haem. The deficiency in the first and rate controlling enzyme - ALA synthase - causes hereditary sideroblas tic anemia, while deficiencies in all the seven subsequent enzymes produce a particular type of porphyria. (ADP, AIP, CEP, PCT/HEP. HCP. VP and EPP). The genetic basis of porphyrias is extremely hete rogeneous with AD and AR inherited types of porphyria. Numerous different gen mutations have been described in every type of porphyria. Mutations may produce from no manifestations - clinical and/or biochemical - to extremely severe disease in double heterozygous or homozygous patients. Characterization of the different porphyrias inlcude: clinical manifestations-cutaneous photosensitivity and/or acute attacks-biochemical alteration pattern, level of enzyme activity and genetic studies. Other points of interest in porphyrias arc: I- triggering factors - porphyrinogenic factors which induce clinical overt manifestation of the disease; 2- association to other diseases either hereditary (hemochromatosis) or acquired (viral hepatitis, HIV infection); 3-possible appearance of hepatocellular carcinoma or life threatening liver failure. Treatment is usually unsuccesful except in porhyria cutanea tarda. We can also instruct patients about preventive mesures: photoprotection and avoidance of porphyrinogenic drugs, useful in other forms of porhyria.

Course

C6. Cutaneous

Models for genetic engineering based treatments are in development.

Cutaneous pathology

C6. ElC6

1 Connective

G.E.

Pitrard. LiPge, Belghml

tissue

Histopathologic criteria apocrine neoplasms

Luis Requena. Deparrment Jittdtez

Dfaz,

Universidad

for diagnosis

of

Histopathologic criteria for recognition of apocrine differentiation in a neoplasm are: (I) “Decapitation” secretion (2) Elongated tubules (3) Polygonal, plasmocytoid, clear, pale, and mutinous cells (4) Tall columnar cells with round nuclei at their base (5) Luminal fringe (6) Papillations (7) Presence of sebaceous and/or follicular differentiation in a ductal neoplasm The features just described represent the less common denominators for identification of neoplasms with apocrine differentiation. Additional findings such as small horny cysts in superficial areas of micmcystic adnexal carcinoma, adenoidcystic pattern in adenoid-cystic carcinoma, cribiform pattern in cribiform carcinoma, or a fenestrated pattern of epithelial aggregations of neoplastic cells surrounded by pools of mucin and separated by thin fibrous septa in mutinous carcinoma, etc. allow a more specific diagnosis of the histopathologic type of apocrine neoplasm.

Philadelphia,

for

ElC6-4 Atypical melanocytic H. Kerl. Graz, Austria

nevi

At the National Institutes of Health Consensus Development Conference 1992 in Bethesda (USA) the panel proposed to abandon dysplastic nevus as a term in diagnosis. It was recommended to describe these lesions as ‘atypical moles’ and ‘nevus with architectural disorder’. These designations are not precise and lack any meaning because many benign proliferations of melanocytes which simulate malignant melanoma, may show repeatedly atypical features and qualify as atypical nevi (Table 1). The knowledge of the simulators of melanoma is of great practical importance to avoid overdiagnosis of malignant melanoma and it is also necessary to identify these tumors with greater specificity. Tuble I: Spectrum of Benign Simulators of Melanomn

of Dermatology, Fundacidn Autdnoma, Madrid. Spain

0C6-3 Melanoma in situ A. Bernard Ackerman. Institute

lesion”, is in the best interest of patients because that diagnosis should telegraph to clinicians two important messages: (I) certain cure following complete excision with narrow margins and (2) increased risk for development of a second melanoma, the latter situation underscoring the need for complete examination of the skin annually. The implication for care of patients is obvious: capability of histopathologists to identify melanoma when it is incipient, i.e., in situ, is lifesaving.

naevi

Connective tissue naevi are not unfrequently a facet of a complex syndrome. They may be conveniently divided according to clinical and pathologic presentations into two types, namely the adventitial and the reticular. Naevi of adventitial connective tissue are usually small and situated on the extremities. They are characterized by accumulations of Factor XIIIa-positive dendrocytes and apposition of lamellar collagen around adnexa and microvasculature. In contrast, naevi of reticular connective tissue are usually situated on the trunk. They are typically cell-poor nodules containing faulty distributions and amounts of collagen bundles, elastic fibers, or proteoglycans. ElC6 2

S51

pathology

Dermatopathology,

USA

Nearly all melanomas primary in the skin begin in situ and some of them are even diagnosable when melanocytes disposed as solitary units are positioned at the junction of dermis and epidermis (and of adnexal epithelium). Specific diagnosis of melanoma in situ, unlike clumsy opaque descriptions of it like “severe melanocytic proliferation”, and “atypical melanocytic

-Spitz’s nevi and vuriunts - ‘Dysplastic’ (Clnrk’s) nevi - Blue nevi and vurionls - Combined nevi -Persistent (recurrent) nevi - Halo nevi -Congenital nevi in newborns - Acml and genital nevi - ‘Ancient’ nevi -Others

ElC6

5

Basal cell carcinoma

E. Grosshans. Clinique Strasbourg,

Dermatologique,

Faculte’de

Mdecine,

France

Basal cell carcinoma (BCC) are the most frequent skin cancers; their registration is not scheduled but they are approximately 5 times more frequent than cutaneous squamous cell carcinomas which represent 3.7 per cent of all registered cancers in Alsace. The rate of death due to BCC is less than 1 per cent and the rate of metastases less than 0.1 per cent. There is a good correlation between the histologic pattern and the chance of a complete removal by simple surgical excision. Nodular BCC, superficial BCC either of the pagetoid or the scarring type and fibro-epithehal BCC of the Pinkus type are easily removed with a low risk of recurrences. BCC with a trabecular or a morpheic pattern, especially in the anatomical clefts of the face, around the nose, the eyes and the ears, have poorly limited margins and need to be thoroughly checked on multiple slides. The basaloid cells loose the peripheral palisading and may even keratinize in the baso-squamous (“metatypical”) subtype which shows the biological behaviour of a differentiated squamous cell carcinoma. Even if this aggressive subtype is only focally present it conferes that feature on the tumor and should be indicated in the pathological report.