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Dive into the research topics where Pierre Chavaz is active.

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Featured researches published by Pierre Chavaz.


Journal of The American Academy of Dermatology | 1992

Orbital and palpebral paraffinoma

Robert Feldmann; Monika Harms; Pierre Chavaz; Denis Salomon; Jean-Hilaire Saurat

Paraffinoma is a well-recognized complication of paraffin injection. We describe a 44-year-old man who had an ethmoidectomy for chronic sinusitis. A communicating fracture of the ethmoid bone into the orbit occurred intraoperatively. The nasal cavity was subsequently packed with gauze containing a petrolatum-based antibiotic ointment. Bilateral, periocular swelling developed 1 week later. Optical and electron microscopic studies revealed a paraffinoma.


Dermatology | 2002

Basal Cell Carcinoma of the Earlobe after Auricular Acupuncture

Michel Brouard; Gürkan Kaya; Gianluca Vecchietti; Pierre Chavaz; Monika Harms

The genesis of familial and sporadic basal cell carcinomas involves activation of the Sonic hedgehog signal transduction pathway. Other known factors for the development of basal cell carcinoma are ultraviolet exposure, X-rays, race, age, gender and decreased DNA repair capacity. We here report the case of a right earlobe sporadic basal cell carcinoma in a 65-year-old woman. This case is unusual because of its earlobe localization and its association with multiple auricular acupuncture treatments. This observation suggests a connection between local traumas, which occur in the course of acupuncture treatment and ear piercing, and the genesis of basal cell carcinoma. The incidence of minor adverse events associated with acupuncture is high, but serious events are uncommon. Acupuncture is not known to date for promoting the development of tumors. This connection remains to be elucidated.


Dermatology | 2001

Chronic Borreliosis Presenting with Morphea- and Lichen sclerosus et atrophicus-Like Cutaneous Lesions

Gürkan Kaya; Magali Berset; Christa Prins; Pierre Chavaz; Jean-Hilaire Saurat

We report on a case of chronic cutaneous borreliosis with manifestations clinically compatible with morphea and lichen sclerosus et atrophicus. The histopathologic features of these lesions were those of acrodermatitis chronica atrophicans. Our case illustrates the concept that clinical aspects of morphea and lichen sclerosus et atrophicus pertain to the spectrum of cutaneous borreliosis.


Cancer | 1993

L-tryptophan-induced eosinophilia-myalgia syndrome associated with primary cutaneous malignant fibrous histiocytoma and extraabdominal desmoid tumor.

Carlo Mainetti; Isabelle Masouyé; Denis Salomon; Pierre Chavaz; Jean-Hilaire Saurat

A 57‐year‐old woman with L‐tryptophan–induced eosinophilia‐myalgia syndrome, 23 months after the onset of symptoms, experienced development of a parasternal malignant fibrous histiocytoma on previously scleroderma‐like skin areas and, almost concurrently, an extraabdominal desmoid tumor of the left arm muscle fascia. The malignant fibrous histiocytoma was treated by surgical excision without sign of recurrence or metastasis 19 months later. Radiation therapy was performed on the extraabdominal desmoid tumor. We suspect that these two connective tissue tumors in this patient were related to the exposure to contaminated L‐tryptophan, which interfered with connective tissue metabolism.


Journal of Cutaneous Pathology | 2006

CD44 and hyaluronate expression in follicular mucinosis

Gürkan Kaya; Eric Augsburger; Pierre Chavaz; Jean-Hilaire Saurat

Background:  CD44 is a membrane glycoprotein and the major cell‐surface receptor of hyaluronate (HA). Lack of CD44 expression in mouse epidermis leads to an abnormal HA accumulation in the dermis, indicating an important role of CD44 in local HA metabolism. Decrease of epidermal CD44 expression in patients of lichen sclerosus et atrophicus is potentially responsible for dermal deposition of HA in this disease. Stromal HA accumulation is associated with decreased or lost expression of CD44 in perifollicular solitary cutaneous myxoma, myxoid dermatofibroma, and dermatofibrosarcoma protuberans.


Dermatology | 1984

Dermatosis of hairless rats fed a hypomagnesic diet. Pathology and immunology

Pierre Chavaz; F. Faucher; Jean Hilaire Saurat

The histopathology of hypomagnesic dermatosis in the hairless rat was studied on semithin sections, by electron microscopy, direct immunofluorescence and monoclonal antibodies to T cell subsets. We found primarily an edema of the epidermis and of the superficial dermis with a moderate mononuclear infiltrate and sometimes intraepidermal splits. The immunofluorescent study did not reveal any significant immune reactant within the skin. The comparison of our findings with the histopathology of the atopic dermatitis did not allow us to propose the hypomagnesic dermatosis as an animal model for human atopic dermatitis. We discuss some aspects of the pathogenesis of this chronic inflammatory dermatosis.


Dermatology | 2001

Alopecia syphilitica: Report of Two Cases in Geneva

A. Friedli; Pierre Chavaz; Monika Harms

Two patients with alopecia syphilitica are presented. Moth-eaten alopecia is the most typical look of secondary syphilis on the scalp. With the decrease in syphilis cases in western countries, this rarer clinical manifestation tends to be misdiagnosed.


Journal of Cutaneous Pathology | 2008

Giant cell lichenoid dermatitis in a patient with baboon syndrome

Elhem Khelifa‐Hamdani; Monia Touati‐Serraj; Jacqueline Perriard; Pierre Chavaz; Jean-Hilaire Saurat; Gürkan Kaya

Giant cell lichenoid dermatitis is a recently described pathological entity, which can be seen as an unusual lichenoid drug eruption, a manifestation of sarcoidosis or within herpes zoster scars. Histopathological findings include focal vacuolar alteration of the basal layer with cytoid bodies, dermal and intraepidermal multinucleated giant cells and a mixed chronic inflammatory infiltrate with a lichenoid pattern consisting of lymphocytes, histiocytes, eosinophils and plasma cells. Here, we report a giant cell lichenoid dermatitis in a 41‐year‐old male patient who developed, 3 days after intravenous treatment with amoxicillin‐clavulanic acid for erysipelas of the left leg, a clinical picture suggesting a baboon syndrome characterized by an erythematous and pruritic eruption on the axillary, inguinal and popliteal areas and the anterior side of elbows. This is the first reported case of giant cell lichenoid dermatitis in a patient with baboon syndrome.


Dermatology | 2003

Decreased CD44 expression and stromal hyaluronate accumulation in myxoid dermatofibroma.

Emel Calikoglu; Pierre Chavaz; Jean-Hilaire Saurat; Gürkan Kaya

Background: Dermatofibroma (DF) is a common benign histiocytic tumor, which has several clinicopathological variants. Myxoid DF is one of these variants, which is characterized by a stromal mucin deposition. CD44 is a polymorphic transmembrane glycoprotein and the principal cell surface receptor of hyaluronate (HA), the major component of the extracellular matrix. In a recent study, we have observed an abnormal accumulation of HA in the superficial dermis of transgenic mice with a keratinocyte-specific CD44 expression defect. We have also shown that HA was accumulated in large amounts in the superficial dermis of lichen sclerosus et atrophicus (LSA) lesions and that the epidermal CD44 expression of LSA skin was significantly decreased or lost. In an another study, we have suggested that a decrease in CD44 expression in follicular epithelial proliferations might be correlated with an abnormal HA accumulation in perifollicular solitary cutaneous myxoma. Recently we have also demonstrated that classical DF lesions displayed a strong CD44 expression in tumor cells and a weak HA positivity in tumor stroma whereas CD44 expression was significantly reduced or absent in dermatofibrosarcoma lesions and the tumor stroma showed strong HA staining. Objective and Methods: Here we present 3 cases of myxoid DF, in which we explored the nature of the mucinous material in myxoid stroma by colloidal iron and hyaluronic acid binding protein stainings, as well as the expression of CD44 in the tumor cells by immunohistochemistry. Results: We show that HA is accumulated in the stroma of all myxoid DF lesions with a significant decrease in CD44 expression in the tumor cells. Conclusion: Our results suggest that a decrease in CD44 expression in the tumor cells may result in stromal myxoid changes characterized by an abnormal HA accumulation in myxoid DF.


Dermatology | 2002

Hyaluronate accumulation and decreased CD44 expression in perifollicular solitary cutaneous myxoma.

Emel Calikoglu; Eric Augsburger; Isabelle Masouyé; Pierre Chavaz; Jean-Hilaire Saurat; Gürkan Kaya

Background: Myxomas are rare cutaneous tumors which may be solitary or associated with Carney’s complex, NAME or LAMB syndromes. The mucinous material which constitutes the stroma of cutaneous myxomas is predominantly composed of hyaluronate (HA), the major component of the extracellular matrix. CD44 is a polymorphic integral membrane glycoprotein which serves as the principal cell surface receptor for HA. Objective and Methods: Here we present 2 cases of solitary cutaneous myxomas displaying microscopically a perifollicular localization, in which we explored the nature of the accumulated mucinous material by colloidal iron and HA-binding protein stainings, as well as the epidermal expression of CD44 protein by immunohistochemistry. Results: We show that HA is accumulated in the stroma of the cutaneous myxoma lesions and that the protein expression of CD44 in the keratinocytes of the trichofolliculoma-like epithelial buds projecting from the hair follicle centering these lesions is significantly decreased. Conclusions: Our results suggest that a decrease in CD44 expression in follicular epithelial proliferations may be correlated with an abnormal HA accumulation in cutaneous myxoma.

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