Acquired cystic disease-associated renal cell carcinoma (ACD-RCC) is a recently described subtype of RCC found in individuals with ACD of the kidney. Because of underrecognition, information regarding this lesion is sparse but continues to accumulate with each new report. Herein, a thorough literature review amassing the current understanding of this unique neoplasm is presented. Discussion focuses on clinical features, pathogenesis, disease outcome, and relation to the duration of dialysis. The macroscopic and characteristic microscopic features are described with illustrations. Compared with previous opinion, compiled immunohistochemical data may now allow for recognition of a unique immunophenotypic pattern of ACD-RCC. Distinction of ACD-RCC from clear cell and papillary RCCs based on molecular genetic information is deliberated, including a summary of the most frequently detected cytogenetic abnormalities. The key morphologic and immunophenotypic patterns used to distinguish this entity from a comprehensive differential diagnosis are provided.

Context.-An explosion of information on pulmonary hypertension has occurred during the past few decades. The perception of this disease has shifted from purely clinical to incorporate new knowledge of the underlying pathology. This transfer has occurred in light of advancements in pathophysiology, histology, and molecular medical diagnostics.Objectives.-To update readers about the evolving understanding of the etiology and pathogenesis of pulmonary hypertension and to demonstrate how pathology has shaped the current classification.Data Sources.-Information presented at the 5 World Symposia on pulmonary hypertension held since 1973, with the last meeting occurring in 2013, was used in this review.Conclusions.-Pulmonary hypertension represents a heterogeneous group of disorders that are differentiated based on differences in clinical, hemodynamic, and histopathologic features. Early concepts of pulmonary hypertension were largely influenced by pharmacotherapy, hemodynamic function, and clinical presentation of the disease. The initial nomenclature for pulmonary hypertension segregated the clinical classifications from pathologic subtypes. Major restructuring of this disease classification occurred between the first and second symposia, which was the first to unite clinical and pathologic information in the categorization scheme. Additional changes were introduced in subsequent meetings, particularly between the third and fourth World Symposia meetings, when additional pathophysiologic information was gained. Discoveries in molecular diagnostics significantly progressed the understanding of idiopathic pulmonary arterial hypertension. Continued advancements in imaging modalities, mechanistic pathogenicity, and molecular biomarkers will enable physicians to define pulmonary hypertension phenotypes based on the pathobiology and allow for treatment customization.

Background Mantle cell lymphoma (MCL) is an incurable B‐cell lymphoma portending an aggressive clinical course; the blastoid and pleomorphic morphological variants have an even worse prognosis. In addition, patients with classic morphology and a high proliferation index (HPI), also have reduced survival. Although variants have been defined, to the authors’ knowledge the ability to detect these subtypes by fine‐needle aspiration biopsy (FNAB) has not been described. Methods MCL cases diagnosed by lymph node FNAB with concurrent core needle biopsy were reviewed from 146 patients, accounting for 172 specimen pairs. FNAB and core needle biopsy diagnoses were compared to determine concordance rates. Flow cytometric immunophenotype and Ki‐67 rates were evaluated. Results The classic subtype was diagnosed in 58% of cases (99 of 172 pairs) and variant morphology was diagnosed in 42% of cases (73 of 172 pairs) by histology. Twenty‐nine patients presented with variant morphology whereas 28 underwent transformation. A nontraditional immunophenotype including loss of CD5 or FMC‐7 and expression of CD23 and CD10 was found in 44% of variants (29 of 66 variants) and 19% of classic subtypes (18 of 94 classic subtypes) (P = .0008). Ki‐67 rates averaged from 56% to 76% for blastoid and pleomorphic cases, 53% to 55% for MCL‐HPI cases, and 17% to 19% for classic cases. The sensitivity and specificity to detect MCL variants by FNAB were 74% and 93%, respectively. Conclusions The accuracy of diagnosing MCL is high when adequate samples for cytomorphology and flow cytometry are obtained. Subtyping variants by cytomorphology alone has challenges, but overall demonstrates high sensitivity and specificity. The performance of Ki‐67 on cytology specimens is useful for detecting MCL with HPI.

To assess the impact of preanalytical variables of time and temperature on prothrombin time (PT), activated partial thromboplastin time (aPTT), dilute Russell viper venom time (DRVVT), activated protein C resistance (APCR), and d-dimer, samples from 23 healthy individuals and 18 patients having coagulopathy with known abnormal PT and aPTT were collected. Plasma from each individual was separately pooled and aliquoted; the first 2 aliquots were stored at room temperature then analyzed at 2 hours (baseline) and 4 hours postcollection. The remaining aliquots were stored at -20°C and thawed for analysis at 48 hours, 1, and 2 weeks. In both healthy participants and participants with coagulopathy, PT, aPTT, APCR, DRVVT, and D-dimer had no significant changes at 4 and 48 hours, and 1 and 2 weeks postcollection compared to baseline, or the changes were less than 10%. The results indicate PT, aPTT, DRVVT, APCR, and d-dimer can be stored for 2 weeks at -20°C without compromising clinical interpretation in both healthy individuals and individuals with coagulopathy. Increasing storage time will facilitate sample processing from off-site clinics.

Kikuchi Fujimoto's disease (KFD) is a rare, immune-mediated, self-limiting disorder with unique histopathological features. KFD is usually seen in young Asian females; however, cases have been reported throughout the world and in all ethnicities. It has been recognized that there is a rare association between Systemic Lupus Erythematosus (SLE) and KFD via sporadic case reports. The exact pathophysiological relationship between these two diseases is still unclear. We report a case of a young Asian female who presented with persistent fever and lymphadenopathy and was diagnosed with Kikuchi Fujimoto's disease based on lymph node biopsy; although an SLE workup was done, she did not meet the American Rheumatology Association (ARA) diagnostic criteria for lupus, and the lymph node biopsy did not show features of SLE. She improved clinically with a short course of steroid therapy. Two months later, the patient presented with central facial rash and arthralgia. SLE workup was repeated, a skin biopsy was done, and the results at this time supported a diagnosis of SLE.