Little is known about the aminopeptidase CD13 in renal neoplasia according to the new 2016 World Health Organization renal tumor classification. We selected 175 cases, including 79 clear cell, 31 papillary, 24 chromophobe, 8 clear cell papillary renal cell carcinomas (RCCs), 21 oncoytomas, and 12 microphthalmia transcription factor family translocation RCCs: 4 t(6;11)/transcription factor EB (TFEB), 7 t(Xp11) with 2 cystic variants and 1 t(X;17). GATA binding protein 3 (GATA-3) was inserted as control. Expression of proximal antigen CD13 was observed in 63/79 (80%) clear cell, 25/31 (81%) papillary, 3/8 (37%) clear cell papillary, 1/4 (25%) t(6;11)/TFEB, 2/7 (28%) cystic t(Xp11), and in 1/1 t(X;17) RCCs. All chromophobe RCC (0/24) and all oncocytomas (0/21) resulted negative. CD10 was seen in 76/79 (96%) clear cell, 15/31 (48%) papillary, 10/24 (42%) chromophobe, 1/8 (12%) clear cell papillary RCCs, 4/21 (19%) oncocytomas, 1/4 (25%) t(6;11)/TFEB, 2/7 (29%) cystic t(Xp11), and in 1/1 t(X;17) RCCs. GATA-3 was positive in 3/7 (42%) clear cell papillary RCCs and negative in all remaining RCCs, except a single chromophobe RCC and a single oncocytoma. We concluded that: (1) CD13 and GATA-3 immunostains may serve as a diagnostic aid in differentiating subtypes of RCC; (2) CD13 is always absent in chromophobe RCC and oncocytomas, whereas CD10 can be immunoexpressed in both; (3) CD13 should be included in a panel of antibodies to distinguish "proximal renal tumors" from "distal renal tumors" and between clear cell RCC versus microphthalmia transcription factor family translocations RCCs; and (4) when present, GATA-3 is specific for clear cell papillary RCC.

Follicular lymphoma is characterized by aberrant BCL2 expression, a feature that is exploited for diagnostic purposes. However, a certain percentage of follicular lymphomas might be BCL2-negative by immunohistochemistry, increasing the difficulties in differentiating them from follicular hyperplasia. The expression of TUBB3 has been recently reported as negative in a small series of follicular lymphomas. We have therefore tested a larger series, including 61 BCL2-positive and 25 BCL2-negative cases, and compared them with 61 reactive lymphoid tissues. First, a subjective score of TUBB3 staining was applied, showing that it was consistently positive in reactive germinal centers, while most follicular lymphomas were negative; in fact, only 10/61 (16%) BCL2-positive and 1/25 (4%) BCL2-negative cases showed a positive staining for TUBB3, while 58/ 61 (95%) of tissues with follicular hyperplasia were positive. The application of a standardized scoring system to a large number of follicles, based on virtual slides, demonstrated that reactive lymphoid tissues had a significantly higher number of TUBB3-positive follicles both compared with BCL2-positive cases and to BCL2-negative cases. Our data support the use of TUBB3 staining in differentiating follicular lymphoma, including BCL2-negative cases, from follicular hyperplasia.

Patient: Male, 72Final Diagnosis: Fat lung embolismSymptoms: DyspneaMedication: —Clinical Procedure: —Specialty: Orthpedics and TraumatologyObjective:Diagnostic/therapeutic accidentsBackground:Fat embolism syndrome is a well-known complication in orthopedic and trauma surgery, caused by a massive release of fat into the circulation that can lead to cardiopulmonary insufficiency and multiorgan failure.Case Report:We present the case of a 72-year-old man with osteoarthritis who underwent an elective right cementless total hip arthroplasty. Two hours after surgery, the patient lost consciousness and was found hypotensive and with reduced oxygen saturation, with a severe right heart dilatation at echocardiographic evaluation. Death occurred after cardiopulmonary resuscitation attempts. Post-mortem microscopic examination revealed that the final cause of death was pulmonary fat embolism associated with coronary amyloidosis and atherosclerosis.Conclusions:This case called our attention on the sudden onset of fat embolism syndrome after arthroplasty and the insidious nature of amyloidosis infiltrative disease. The autopsy findings substantially aided understanding the immediate cause of death.

Pancreatic metastases are uncommon entities [ 1 , 2 ].Metastases can occur through different ways: by direct invasion, from systemic malignancies such as lymphomas or leukemias, or by metastatic spread from a distant tumor [ 3 ].Primary pancreatic lymphoma is another rare pancreatic neoplasm that accounts for less than 1 % of all pancreatic tumors [ 4 ].Compared to primary pancreatic lymphoma, the secondary involvement of the pancreas by non-Hodgkin's lymphoma is more common and can occur in 30-40 % of patients with extranodal disease [ 5 ]. Secondary Tumors and Lymphoma Pathology MetastasesTumors that directly invade the pancreatic parenchyma generally arise from adjacent structures such as Vater's papilla, extrahepatic bile ducts, stomach, duodenum, or colon [ 6 , 7 ]. Pancreatic involvement by lymphomas and leukemias usually derives from the involvement of peripancreatic lymph nodes; overall, this condition can be seen in up to 30 % of patients with widespread disease [ 8 ].True pancreatic metastases more commonly arise from renal cell carcinoma (which are the most frequent), melanoma, and breast and lung adenocarcinoma [ 2 , 9 , 10 ]. The dissemination route to the pancreas can be either lymphatic or hematogenous; the fi rst is pretty typical for colorectal cancer, due to the unique lymphatic drainage through the mesocolon to the pancreas. In these cases, the most frequent site of implantation of metastases is the inferior portion of the pancreatic head.The exact prevalence of pancreatic metastases is not clear: the reported frequency in autoptic studies ranges between 1.6 and 5.9 % [ 2 , 11 , 12 ], while pancreatic metastases have been observed in 0.7-10.7 % of endoscopic ultrasoundguided fi ne-needle aspirations [ 10 , 12 -14 ].

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