McCune-Albright syndrome - A case report with transmission electron microscopy

Abstract McCune - Albright syndrome is a genetic disease with cutaneous mosaicism caused by post-zygotic activating mutations in GNAS locus, it has a triad of fibrous bone dysplasia, café-au-lait macules and precocious puberty. We examined a 22-year-old female patient with café au lait spot in right side of the abdomen, with a chessboard - like distribution, extending to right thigh with geographical contours, she has also an ovarian cyst, scoliosis and truncal obesity. Biopsies were taken from the hyperpigmented area and processed for light microscopy and for transmission electron microscopy. Light microscopy showed increased melanin pigment with HE staining. Immunohistochemistry with melanocytic markers (HMB-45 and Melan-A) revealed a normal number of melanocytes. Transmission electron microscopy demonstrated normal epidermal structures, such as desmosomes, cytokeratin filaments and hemidesmosomes. With high magnifications an irregular melanossomal contour was seen, with some indentations in their outline.

Envolvimento pulmonar na síndrome de Sweet paraneoplásica / Pulmonary involvement in paraneoplastic Sweet's syndrome

Síndrome de Sweet (dermatose neutrofílica febril aguda) é caracterizada por lesões cutâneas inflamatórias acompanhadas por febre, leucocitose e mal-estar, devendo ser reconhecida por hematologistas, já que freqüentemente é paraneoplásica. O envolvimento sistêmico pode estar presente e o comprometimento pulmonar, apesar de raro, tem sido reportado na forma de infiltração pulmonar bilateral, bronquiolite obliterante e derrame pleural. Há infiltração neutrofílica densa na histologia. Apresentamos o caso de uma paciente com leucemia mielóide crônica que desenvolveu a síndrome de Sweet com infiltrações pulmonares não infecciosas, as quais não foram responsivas à antibioticoterapia, porém mostraram melhora clínica com a corticoterapia.

Sweet's syndrome (acute febrile neutrophilic dermatosis) is characterized by inflammatory skin lesions accompanied by fever, leukocytosis and malaise, it should be recognized by hematologists, because it can be a paraneoplastic manifestation. Systemic involvement may be present and lung lesions, despite of the rarity, have been reported in the form of bilateral pulmonary infiltrations, bronchiolitis obliterans and pleural effusion. Histopathology shows dense neutrophilic infiltrates. We present a patient with chronic myeloid leukemia who developed Sweet's syndrome with bilateral pulmonary infiltrations, which were non-responsive to antibiotics but showed clinical improvement on steroid therapy.