CD34-positive superficial myxofibrosarcoma: a potential diagnostic pitfall.

BACKGROUND: Myxofibrosarcoma (MFS) arises most commonly in the proximal extremities of the elderly, where it may involve subcutaneous and dermal tissues and masquerade as benign entities in limited biopsy samples. We encountered such a case, in which positivity for CD34 and morphologic features were initially wrongly interpreted as a 'low-fat/fat-free' spindle cell/pleomorphic lipoma. Case series have not assessed prevalence of CD34 reactivity among cutaneous examples of MFS. METHODS: We performed a systematic review of our institution's experience, selecting from among unequivocal MFS resection specimens those superficial cases in which a limited biopsy sample might prove difficult to interpret. These cases were immunostained for CD34 and tabulated for clinicopathologic characteristics. RESULTS: After review of all MFS diagnoses over 5 years (n = 56), we identified a study group of superficial MFS for comparison to the index case (total n = 8). Of these, the index and three additional cases (4 of 8, 50%; 2 low, 2 high grade) demonstrated positive staining for CD34, with diffuse staining of spindled cells including cellular processes. Four additional cases showed no or equivocal/rare staining. CONCLUSIONS: CD34 positivity should be recognized as prevalent among such cases and should not be inappropriately construed as inveighing against a diagnosis of MFS in favor of benign entities.

Decreased apoptosis in the forebrain of adult male medaka (Oryzias latipes) after aqueous exposure to ethinylestradiol.

Endocrine disrupting compounds (EDCs), especially those that are estrogenic, are an issue of growing concern because they may ultimately adversely affect wildlife survival. 17-beta-Estradiol and its synthetic counterpart, 17-alpha-ethinylestradiol, two common EDCs, are associated with intersex conditions and impaired male reproductive behavior in fish. Male and female Japanese medaka (Oryzias latipes) were exposed to 10 ng/l ethinylestradiol for 6 months. Using terminal dideoxynucleotidyl-mediated dUTP nick end-labeling (TUNEL) to quantitate cell death, we found that ethinylestradiol-exposed males had significantly fewer apoptotic cells in the forebrain compared to untreated males and exposed females. Our results show that the effects of ethinylestradiol exposure are highly variable among individuals of the same species and even within tissues of the same individual. Thus, when examining the effects of EDCs on natural populations, data from a variety of tissues should be examined and the interpretation of any effects should include consideration of tissue-specific processes.