Angiomatoid fibrous histiocytoma is a soft tissue neoplasm of low malignant potential, typically occurring in the superficial soft tissues of the extremities in children and young adults. Occurrence outside somatic soft tissues is most uncommon. This report describes eight such cases, involving the lung (three cases), mediastinum (one case), vulva (two cases), retroperitoneum (one case) and ovary (one case), with the latter three locations being hitherto unreported sites of occurrence. Patients had a median age of 48 years, and presented with symptoms related to the mass lesion (five cases) or were incidentally found to harbor a tumor (three cases). Besides the typical histological features such as an outer shell of lymphoid tissue, multinodular aggregates of dendritic-like tumor cells, blood-filled spaces and abundant admixed plasma cells, unusual features were found focally in some cases, including clear cells, rhabdomyoblast-like cells, pulmonary edema-like pattern and tumor cell cords lying in a myxoid stroma. Immunoreactivity for the epithelial membrane antigen, desmin, smooth-muscle actin, CD68 and CD99 was found in 100, 63, 43, 100 and 100% of cases, respectively. Molecular studies provided support for the diagnosis in all seven tested cases-EWS gene translocation in six cases (partner gene being CREB1 in three and ATF1 in two in which information was available) and FUS gene translocation in one case. Comparison of the reported cases of extrasomatic angiomatoid fibrous histiocytoma with their somatic soft tissue counterparts showed a number of differences: higher mean age, slight male predominance (particularly for bone lesions), larger tumors, higher frequency of systemic symptoms, higher recurrence rate, myxoid change being more common and a much higher frequency of EWS/ATF1 gene fusion.

Patients affected by the multiple endocrine neoplasia type I syndrome (MEN1) display a high incidence of pituitary adenomas, though it is still unknown whether these pituitary tumors have specific pathologic features that would distinguish them from sporadic pituitary adenomas. Pituitary tissue specimens of 77 MEN1 patients from the GTE (Groupe d'étude des Tumeurs Endocrines) register were compared with unselected 2509 non-MEN1 sporadic pituitary tumors and also to a control subgroup of 296 cases, where 1 MEN1 tumor was matched with 4 sporadic tumors of the same hormonal immunoprofile. Sex, age, size, and invasiveness of tumors, and menin gene mutations were documented. Histologic analysis took into account 33 items, including immunocytochemical data, the proliferative marker Ki-67, and an examination of the juxtatumoral pituitary. MEN1 tumors were significantly larger and more often invasive by histology. MEN1 patients with large pituitary tumors (grade IV) were younger than non-MEN1 patients. MEN1 tumors had no other characteristic histologic features and no predominance of any one hormone producing subtype. However, plurihormonal adenomas versus monohormonal and nonimmunoreactive adenomas were more frequent in MEN1 tumors (39%) than in the control non-MEN1 group (P = 0.001). Especially, the growth hormone and prolactin plurihormonality with unusual association with follicle-stimulating hormone, luteinizing hormone, or adrenocorticotropic hormone was more frequent in MEN1 tumors. In addition, multiple adenomas were significantly more frequent (4% vs. 0.1%; P < 0.0001), especially prolactin-adrenocorticotropic hormone. Somatotroph hyperplasia, with or without a microadenoma was found in only 3 MEN1 patients, with growth hormone-releasing hormone hypersecretion by a pancreatic tumor in 2 of them. All types of mutation were observed, including frameshifts, nonsenses, missenses, and 1 case of germline MEN1 encompassing large deletion, strongly suggesting the absence of any phenotype-genotype correlation.

Purpose To prospectively assess the clinical impact of expert review of lymphoma diagnosis in France. Materials and Methods From January 2010 to December 2013, 42,145 samples from patients with newly diagnosed or suspected lymphomas were reviewed, according to the 2008 WHO classification, in real time by experts through the Lymphopath Network. Changes in diagnosis between referral and expert review were classified as major or minor according to their potential impact on patient care. Results The 42,145 reviewed samples comprised 36,920 newly diagnosed mature lymphomas, 321 precursor lymphoid neoplasms, 314 myeloid disorders, and 200 nonhematopoietic neoplasms, with 4,390 benign lesions. There were 4,352 cutaneous and 32,568 noncutaneous lymphomas. The most common mature noncutaneous lymphomas were diffuse large B-cell lymphomas (32.4%), follicular lymphomas (15.3%), classic Hodgkin lymphomas (13%), peripheral T-cell lymphomas (6.3%) of which angioimmunoblastic T-cell lymphomas (2.3%) were the most frequent, and mucosa-associated lymphoid tissue lymphomas (5.8%). A diagnostic change between referral and expert review occurred in 19.7% of patients, with an estimated impact on patient care for 17.4% of patients. This rate was significantly higher for patients sent with a provisional diagnosis seeking expert second opinion (37.8%) than for patients sent with a formal diagnosis (3.7%). The most frequent discrepancies were misclassifications in lymphoma subtype (41.3%), with 12.3% being misclassifications among small B-cell lymphoma entities. Fewer than 2% of changes were between benign and malignant lymphoid conditions. Minor changes (2.3%) mostly consisted of follicular lymphoma misgrading and diffuse large B-cell lymphoma subtype misclassification. Conclusion To our knowledge, this study provides the largest ever description of the distribution of lymphoma entities in a western country and highlights how expert review significantly contributes to a precise lymphoma diagnosis and optimal clinical management in a proportion of patients.