The estrogen receptor (ER)/progesterone receptor (PR)-negative breast carcinomas (BCs) encompass three molecular subtypes: one with human epidermal growth factor receptor 2 (HER) overexpression, one normal like, and the triple negative. The androgen receptor (AR) is expressed in 70-90% of invasive BCs. The aim of our study is to detect the expression of AR in a series of ER/PR-negative BCs to ascertain if there is clinical significance in relation to BC molecular subtypes. A immunohistochemical study for all receptors and cytokeratin expression was performed in 232 cases of ER/PR-negative BCs. According to cytokeratin expression, BCs were classified into two groups: luminal-type BCs (44.2%) and basal-like-type BCs (55.8%). According to the expression of HER2, 59.3% were triple-negative BCs (when ER, PR, and HER2 were negative) and 40.7% were HER2-positive BCs. AR expression was observed in 128 tumors (56.6%). One hundred and ten cases (48.8%) had >10% and 18 (7.8%) had <10% of positively stained cells. AR immunoreactivity was found in 31.2% basal-like BCs, while in the luminal group 71.1% of cases were positive, showing highly significant correlation (p < 10⁻⁸). Regarding HER2 status, 76.7% of HER2-positive BC cases were AR positive compared with only 30.4% of triple-negative BC types, showing a strong statistically significant correlation. In conclusion, we show that AR is frequently expressed in ER/PR-negative BCs and that expression of HER2 and AR is highly correlated (p < 0.005). Our results point out the role of AR and HER2 in the pathogenesis of BCs and suggest the potential role of AR in clinical management of ER/PR-negative BCs.

Poorly differentiated neuroendocrine carcinomas (PDNECs) of the kidney are extremely rare high-grade cancers accounting for only 42 cases reported in the literature. In this paper, we describe the morphological, immunohistochemical, ultrastructural, and for the first time, cytogenetic features of a renal PDNEC. In addition, we have reviewed the literature and compared the published clinicopathological data with our morphological and genetic results. The tumor arose within the kidney parenchyma and showed the typical histological features of a pure small cell PDNEC. Fluorescence in situ hybridization study demonstrated a complex chromosomal assessment indicative of a high degree of chromosome instability with gain of multiple chromosomes, loss of p53, and amplification of myc gene. These results suggest that renal PDNEC has a different genetic background to renal clear cell carcinoma, mainly characterized by the loss of the short arm of chromosome 3. Conversely, genetic alterations seem to resemble those of type 2 papillary renal cell carcinoma. The review of the literature demonstrated that PDNECs are associated with poor prognosis and that parenchymal tumors show some differences from those arising in the pelvis, in that parenchymal tumors are purely neuroendocrine while pelvic tumors are mostly mixed neuroendocrine-exocrine neoplasms.

Cytomegalovirus (CMV) is an opportunistic pathogen causing different diseases in immunocompromised patients and leading to death in a high percentage of cases. CMV infection is also relatively frequent among patients with hematological malignancies, especially when treated with immunosuppressive agents. We describe the clinical history of a patient with stage IV diffuse large B-cell lymphoma (DLBCL) treated with eight courses of R-CHOP every two weeks, who presented clinical remission of the disease at the end of therapy. However, two months later he developed neurological symptoms due to cerebellar involvement and a subcutaneous dorsal lymphomatous infiltration. He had a partial response after chemotherapy and brain radiotherapy, but his clinical course was complicated by fever and hypotension. Although the fever resolved with broad-spectrum antibiotics, he presented progressive endocrine failure and died three weeks later. Autopsy confirmed disseminated multiorgan involvement by DLBCL associated with an unexpected CMV infection of the lungs and several endocrine organs including the pituitary gland, pancreatic islets and adrenals, a clinical association not previously reported in the English literature.

Calretinin expression has been reported in neoplasms arising in various organs, including the breast. We investigated the relationship of calretinin expression with different histological and molecular subtypes of invasive breast carcinomas (IBCs) and its prognostic significance in high-grade female hormone receptor-negative IBCs. A total of 196 cases of IBCs of different histological subtypes were analyzed for immunohistochemical expression of calretinin, human epidermal growth factor receptor 2 (HER2), basal-like (BL), apocrine, and proliferative markers and grouped in different molecular subtypes. We found significant morphological differences in the group of formally classified invasive ductal carcinoma of no special type (IDC-NST), which we further subdivided into two types (type I IDC-NST and type II IDC-NST) according to their morphology. Calretinin expression was found in 55.1% of the IBCs and was strongly associated with carcinoma with medullary features (P = 0.014) and type II IDC-NST (P < 0.001), while type I IDC-NST correlated (P < 0.001) with a lack of calretinin expression. Among the molecular subtypes of IBC, calretinin expression was identified in a significant portion of BL breast cancers (BLBCs), while expression was poor in HER2-overexpressing and molecular-apocrine (MA) HER2-negative subtypes and even less in MA/HER2+ ones. Calretinin expression was significantly associated with high (≥50) Ki-67 (P = 0.02), but not with parameters like age, tumor size, lymph node status, overall survival (OS), and disease-free survival. Calretinin expression is most common in high-grade IBCs with histological medullary features, type II IDC-NST and BL phenotype, and is associated with high neoplastic proliferative index.

PEComas (perivascular epithelioid cell tumors) represent a group of mesenchymal neoplasms showing characteristic morphologic, immunohistochemical, ultrastructural, and genetic features. These neoplasms are usually considered benign, being often well circumscribed by a thin capsule and showing scarce atypia. However, in some cases, they show local invasion and multiple metastases and cause the patient's death. PEComas have been found in many locations, but only 7 cases have been described in the pancreas to date. Here, the authors report an additional case of this rare neoplasm and demonstrate the HMB-45 immunoreactivity of melanosomes or premelanosomes at the ultrastructural level.