Primary atrophic solitary morphea profunda.

Solitary morphea profunda (SMP) is a distinct form of localized scleroderma, a cutaneous disorder of unknown origin. Here, we describe a patient presenting with noninflammatory cupuliform depressed plaques, without any significant skin induration, pigmentation or texture change, that appeared on the left shoulder at a site of previous intramuscular vaccination. Light microscopy studies revealed excessive dermal collagen deposition with thickened hyalinized collagen bundles. Magnetic resonance imaging studies demonstrated tissue fibrosis with thinning of the subcutaneous fat tissue and involvement of the adjacent deltoid muscle, which was confirmed by electromyographic tests. Borrelia serology was negative. Our observation of SMP differed from previously described cases, since it mimicked localized lipoatrophy. Our observation highlights the wide spectrum of clinical presentations of localized scleroderma. The latter should be considered in the presence of lipoatrophy-like lesions for proper workup and therapy.

Giant cell lichenoid dermatitis in a patient with baboon syndrome.

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.

CD44 and hyaluronate expression in follicular mucinosis.

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. METHODS: We examined the expression of CD44 and HA in the skin biopsy specimens of 10 patients with follicular mucinosis by using CD44-specific antibodies and biotinylated HA-binding protein (HABP), respectively. RESULTS: No difference of CD44 expression was observed in the follicular keratinocytes when compared with those of unaffected interfollicular epidermis. The follicular zones of mucin deposition were strongly positive for HA. A weak interkeratinocyte staining for HA was also observed in the interfollicular epidermis. However, HABP staining revealed a stronger reactivity in the follicular keratinocytes surrounding the mucin-accumulated areas compared to the interfollicular keratinocytes. CONCLUSION: Our results suggest an active secretion of HA by follicular cells in follicular mucinosis.

Decreased CD44 expression and stromal hyaluronate accumulation in myxoid dermatofibroma.

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.

CD44 and hyaluronate in the differential diagnosis of dermatofibroma and dermatofibrosarcoma protuberans.

The histological distinction between dermatofibroma (DF) and dermatofibrosarcoma protuberans (DFSP) may be extremely difficult. CD34 and Factor XIIIa have been used to differentiate DF from DFSP. However, there is an overlap and relative lack of specificity of their expressions. CD44 is a widely distributed integral membrane glycoprotein, which is expressed as a multitude of isoforms generated by alternative splicing of at least 10 different variant exons and post-translational modifications. CD44 is currently thought to be the principal cell surface receptor for hyaluronate (HA), the major component of the extracellular matrix. In this study we aimed to assess the expression of standard CD44 (CD44s) and its isoforms (CD44v3, CD44v4, CD44v5, CD44v6, CD44v7, CD44v7v8, and CD44v10), and HA in DF and DFSP. Immunohistochemical staining was performed on the biopsy specimens of 15 cases of DF and four cases of DFSP, using antibodies that recognize the CD44s, different CD44 isoforms and the hyaluronate binding protein (HABP). Tumor cells displayed a strong CD44s immunoreactivity in all cases of DF whereas a faint HA positivity was observed in the tumor stroma. The DF cells were negative for CD44v3, CD44v4, CD44v6, CD44v7 and CD44v7v8 but showed a strong reactivity for CD44v5 and CD44v10. In contrast, CD44s' expression was significantly reduced or absent in all DFSP lesions and the tumor stroma displayed strong staining for HA. Our results indicate that CD44 and HA can be used as additional diagnostic markers to distinguish DF from DFSP.

African tick bite fever: not a spotless rickettsiosis!

African tick bite fever is caused by Rickettsia africae, a newly recognized species from South Africa. We report the case of a patient with an unusual site of a tick bite and discuss cutaneous differences from other spotted fevers that may help dermatologists with clinical diagnosis.

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

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.

Basal cell carcinoma of the earlobe after auricular acupuncture.

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.