Cold-associated perniosis of the thighs histopathologically mimicking lupus. Six observations.

BACKGROUND: Equestrian cold panniculitis has been described since 1980 in horse riders or in stable employees. Histological aspect is underdescribed. PATIENTS AND METHODS: We describe clinical and histological features of six horse riding or stable employees patients presenting with upper lateral thigh lesions during the winter months between 2014 and 2016 in our dermatological department. RESULTS: Six horse riding or stable employees ladies without any known disease presented with similar symptoms. They had urticarial or violaceous, slightly pruritic, sometimes necrotic lesions of the upper lateral thighs. Clinically, equestrian cold panniculitis, insect bite or a caustic dermatitis was suspected. Four of these patients had a cutaneous biopsy. They all showed a similar histological appearance resembling lupus erythematosus, combining dermo-epidermal lesions, with foci of interface dermatitis, an abundant dermal lymphocytic infiltrate and a dermal mucinosis. Hypodermal infiltration was present on samples including subcutis. Laboratory workup for systemic disease was unremarkable for two patients and not performed for the four others, having no other clinical sign of lupus. All patients improved rapidly with very high potent topical steroids. CONCLUSION: Cold-associated perniosis of the thighs should be considered whenever a histopathological appearance of lupus is associated with lesions of the upper lateral thighs in patients practicing horse riding. This disease belongs to the spectrum of miscellaneous cold-induced dermatoses in which histopathological lesions identical to lupus can be encountered.

Bilateral renal lymphangiomatosis: imaging and histopathologic findings.

Renal lymphangiomatosis is an extremely rare disease characterized by developmental malformation of the lymphatic system surrounding the kidneys. We present the case of a 22-year-old pregnant female discovered because of worsening. Ultrasound, computed tomography, and magnetic resonance imaging studies were performed. An 18 × 11 × 10 cm voluminous cystic subcapsular lesion compressing the left kidney and subcapsular cysts of the right kidney were found. After the delivery, marsupialization was performed and the pathological analysis confirmed the diagnosis of lymphangiomatosis. A review of the literature is proposed.

[Post-radiation atypical vascular lesions and angiosarcoma: 11 cases]. / Lésions vasculaires atypiques et angiosarcomes post-radiothérapie : 11 cas.

BACKGROUND: Post-radiation atypical vascular lesions of the skin display clinical and morphological overlap with well-differentiated angiosarcomas, and correct diagnosis may be difficult. PATIENTS AND METHODS: We studied clinical, histological and immuno-histochemical aspects (CD31, CD34, D2-40 and VEGFR-3) of eight post-radiation atypical vascular lesions comparatively with three post-radiation angiosarcomas. RESULTS: All patients were female and received radiation therapy for breast carcinoma. On average, atypical vascular lesions occurred 4.3 years after radiation therapy and presented as small papulonodules or erythematous plaques. The clinical course after simple excision was benign. Histologically, they were relatively circumscribed lesions and showed slit-like vessels dissecting dermal collagen in all cases. On average, angiosarcomas occurred 5 years after radiation therapy and presented as more extensive lesions with a more aggressive clinical course. The lesions showed histological overlap with atypical vascular lesions, but were poorly circumscribed, with deeper invasion, cytological atypia and mitosis. Although the immuno-histochemical profiles were similar, expression of VEGFR-3 was greater in two cases of angiosarcoma. CONCLUSION: Post-radiation atypical vascular lesions are benign lesions that display clinical, histological and immuno-phenotypic overlap with well-differentiated angiosarcoma, and diagnosis requires good clinicopathological correlation. VEGFR-3 may be useful for differential diagnosis, as well as amplification of the MYC gene.