Luis E. De Las Casas

Tumor-to-Tumor Metastasis: Renal Cell Carcinoma Metastatic to Papillary Carcinoma of Thyroid—Report of a Case and Review of the Literature

Metastatic disease to thyroid gland is a rare event. Although renal cell carcinoma (RCC) has been reported to metastasize the thyroid gland, metastatic RCC to a thyroid neoplasm is very unusual. We report a case of a 68-year-old man with history of RCC who presented with a 2.5-cm thyroid nodule. Histologic examination demonstrates a renal cell carcinoma metastatic to a papillary carcinoma of the thyroid. The clinicopathologic features of metastatic disease into a thyroid gland neoplasm are shown, and a review of the literature is presented.

Primary Meningeal Rhabdomyosarcoma in a Child With Hypomelanosis of Ito

Intracranial rhabdomyosarcomas are rare neoplasms, and those thought to be primary meningeal tumors are even more rare. Hypomelanosis of Ito is a neurocutaneous disorder believed to involve a defect in cells of neural crest origin. We report the case of a 15-month-old boy with hypomelanosis of Ito who developed a primary meningeal rhabdomyosarcoma. The patient initially presented with hydrocephalus and 2 months later developed neurologic signs localizing to the spinal cord. Radiologic studies revealed widespread leptomeningeal enhancement with compression of the spinal cord at C5-C7. A brain biopsy revealed a tumor diffusely involving the meninges. Microscopically, the tumor was composed of rhabdomyoblasts, many of which showed prominent cross-striations on routine hematoxylin-eosin staining. To the best of our knowledge, this is the first reported case of meningeal rhabdomyosarcoma in a patient with hypomelanosis of Ito and the fourth reported case of a primary meningeal rhabdomyosarcoma reported in the world literature.

AIDS Presenting with Cutaneous Kaposi's Sarcoma and Bacillary Angiomatosis in the Bone Marrow Mimicking Kaposi's Sarcoma

Kaposis sarcoma (KS) and bacillary angiomatosis (BA) may be histologically similar. A precise diagnosis is required because of the different management of these diseases. KS or BA involving bone marrow is rare in patients with and without acquired immune deficiency syndrome (AIDS). We report the case of a 40-year-old human immunodeficiency virus (HIV)-positive homosexual male who presented with small KS lesions in the skin and BA in the bone marrow that histologically were similar. Laboratory evaluation revealed anemia and thrombocytopenia; CD4 count was 103/mm3, and the viral load was 750,000 HIV-1 mRNA copies per milliliter in plasma. Bartonella henselae, the etiologic agent of BA, was isolated from a blood culture. DNA sequences of human herpesvirus-8 (HHV-8), the putative etiologic agent of KS, were identified by polymerase chain reaction (PCR) in skin and bone marrow specimens, but antibody anti-HHV-8-encoded protein ORF73, localized signals only in the skin-KS lesion. The patient received clarithromycin and cefotetan for the BA, and antiretroviral therapy for the HIV infection. The skin lesions gradually regressed, the HIV-1 mRNA copy number decreased to less than 400 per milliliter and the CD4 lymphocyte count increased to 665/mm3. In conclusion, vascular lesions of BA and KS may be clinically and histologically similar, both may be associated with advanced AIDS, and an accurate diagnosis is required because of their different management.

Phosphorylation of tyrosine 285 of PAK1 facilitates βPIX/GIT1 binding and adhesion turnover

The p21‐activated serine‐threonine kinase (PAK1) regulates cell motility and adhesion. We have previously shown that the prolactin (PRL)‐activated tyrosine kinase JAK2 phosphorylates PAK1 in vivo and in vitro and identified tyrosines 153, 201, and 285 in PAK1 as sites of JAK2 tyrosyl phosphorylation. Here, we further investigate the role of the tyrosyl phosphorylated PAK1 (pTyr‐PAK1) in regulation of cell adhesion. We use human breast cancer T47D cell lines that stably overexpress PAK1 wild type or PAK1 Y3F mutant in which these 3 JAK2 phosphorylation sites were mutated to phenylalanine. We demonstrate that PRL/JAK2‐dependent phosphorylation of these tyrosines promotes a motile phenotype in the cells upon adhesion, participates in regulation of cell adhesion on collagen IV, and is required for maximal PAK1 kinase activity. Down‐regulation of PAK1 abolishes the effect of PAK1 on cell adhesion. We show that the tyrosyl phosphorylation of PAK1 promotes PAK1 binding to β‐PAK1‐interacting guanine‐nucleotide exchange factor (βPEX) and G protein‐coupled receptor kinase‐interacting target 1 (GIT1), phosphorylation of paxillin on Ser273, and formation and distribution of adhesion complexes. Using phosphospecific antibodies (Abs) directed to single phosphorylated tyrosines on PAK1, we identified Tyr285 as a site of PRL‐dependent phosphorylation of PAK1 by JAK2. Furthermore, using PAK1 Y285F mutant, we provide evidence for a role of pTyr285 in cell adhesion, enhanced bPIX/GIT1 binding, and adhesion turnover. Our immunohistochemistry analysis demonstrates that pTyr285‐PAK1 may modulate PAK1 signaling during tumor progression.—Hammer, A., Oladimeji, P., De La Casas, L. E., Diakonova, M., Phosphorylation of tyrosine 285 of PAK1 facilitates bPIX/GIT1 binding and adhesion turnover. FASEB J. 29, 943–959 (2015). www.fasebj.org

Myelopoiesis in the liver of stillborns with evidence of intrauterine infection.

CONTEXT Chorioamnionitis is the maternal and fetal response to an ascending intrauterine infection. The fetal response is manifested by funisitis and chorionic vasculitis, or as neutrophils within pulmonary spaces. Human hematopoiesis occurs in the liver primarily during the 6th to 22nd weeks of gestation. OBJECTIVE To establish the relationship between the presence of an intrauterine infection and the degree of fetal hepatic myelopoiesis in second- and third-trimester fetuses. DESIGN Liver and lungs from 49 fetal autopsies, 20 to 41 weeks of gestational age, and their associated placentas and membranes were analyzed for evidence of intrauterine infection and hepatic myelopoiesis. Hematoxylin-eosin-stained sections from fixed tissues were evaluated for the presence of amnionic fluid infection, defined by the presence of acute chorioamnionitis or funisitis. The degree of portal hematopoiesis, myelopoiesis and intra-alveolar neutrophils was assessed semiquantitatively with hematoxylin-eosin-stained sections and immunohistochemically with antimyeloperoxidase. The Kruskal-Wallis 1-way analysis of variance and the Wilcoxon-Mann-Whitney test were used to determine the significance of any observed difference. RESULTS The degree of portal and lobular myelopoiesis was significantly greater with the presence of inflammation in both the membranes and umbilical cord, and correlated with the presence of intra-alveolar neutrophils (P < .001). A high correlation between the hematoxylin-eosin and immunohistochemistry assessment of myeloid cells was noted. CONCLUSIONS There is increased portal and lobular myelopoiesis in 20-week to 41-week gestational age fetal livers that is associated with intrauterine ascending infection. The presence of increased portal or lobular myelopoiesis suggests the presence of an active fetal response to an intrauterine ascending infection.

A Multiplex Two-Color Real-Time PCR Method for Quality-Controlled Molecular Diagnostic Testing of FFPE Samples

Background Reverse transcription quantitative real-time PCR (RT-qPCR) tests support personalized cancer treatment through more clinically meaningful diagnosis. However, samples obtained through standard clinical pathology procedures are formalin-fixed, paraffin-embedded (FFPE) and yield small samples with low integrity RNA containing PCR interfering substances. RT-qPCR tests able to assess FFPE samples with quality control and inter-laboratory reproducibility are needed. Methods We developed an RT-qPCR method by which 1) each gene was measured relative to a known number of its respective competitive internal standard molecules to control for interfering substances, 2) two-color fluorometric hydrolysis probes enabled analysis on a real-time platform, 3) external standards controlled for variation in probe fluorescence intensity, and 4) pre-amplification maximized signal from FFPE RNA samples. Reagents were developed for four genes comprised by a previously reported lung cancer diagnostic test (LCDT) then subjected to analytical validation using synthetic native templates as test articles to assess linearity, signal-to-analyte response, lower detection threshold, imprecision and accuracy. Fitness of this method and these reagents for clinical testing was assessed in FFPE normal (N = 10) and malignant (N = 10) lung samples. Results Reagents for each of four genes, MYC, E2F1, CDKN1A and ACTB comprised by the LCDT had acceptable linearity (R2>0.99), signal-to-analyte response (slope 1.0±0.05), lower detection threshold (<10 molecules) and imprecision (CV <20%). Poisson analysis confirmed accuracy of internal standard concentrations. Internal standards controlled for experimentally introduced interference, prevented false-negatives and enabled pre-amplification to increase signal without altering measured values. In the fitness for purpose testing of this two-color fluorometric LCDT using surgical FFPE samples, the diagnostic accuracy was 93% which was similar to that previously reported for analysis of fresh samples. Conclusions This quality-controlled two-color fluorometric RT-qPCR approach will facilitate the development of reliable, robust RT-qPCR-based molecular diagnostic tests in FFPE clinical samples.

RKIP Inhibits Local Breast Cancer Invasion by Antagonizing the Transcriptional Activation of MMP13.

Raf Kinase Inhibitory Protein or RKIP was initially identified as a Raf-1 binding protein using the yeast 2-hybrid screen. RKIP inhibits the activation phosphorylation of MEK by Raf-1 by competitively inhibiting the binding of MEK to Raf-1 and thus exerting an inhibitory effect on the Raf-MEK-Erk pathway. RKIP has been identified as a metastasis suppressor gene. Expression of RKIP is low in cancer metastases. Although primary tumor growth remains unaffected, re- expression of RKIP inhibits cancer metastasis. Mechanistically, RKIP constrains metastasis by inhibiting angiogenesis, local invasion, intravasation, and colonization. The molecular mechanism of how RKIP inhibits these individual steps remains undefined. In our present study, using an unbiased PCR based screening and by analyzing DNA microarray expression datasets we observe that the expression of multiple metalloproteases (MMPs) including MMP1, MMP3, MMP10 and MMP13 are negatively correlated with RKIP expression in breast cancer cell lines and clinical samples. Since expression of MMPs by cancer cells is important for cancer metastasis, we hypothesize that RKIP may mediate suppression of breast cancer metastasis by inhibiting multiple MMPs. We show that the expression signature of RKIP and MMPs is better at predicting high metastatic risk than the individual gene. Using a combination of loss- and gain-of-function approaches, we find that MMP13 is the cause of RKIP-mediated inhibition of local cancer invasion. Interestingly expression of MMP13 alone is not sufficient to reverse the inhibition of breast cancer cell metastasis to the lung due to the expression of RKIP. We find that RKIP negatively regulates MMP13 through the Erk2 signaling pathway and the repression of MMP13 by RKIP is transcription factor AP-1 independent. Together, our findings indicate that RKIP inhibits cancer cell invasion, in part, via MMP13 inhibition. These data also implicate RKIP in the regulation of MMP transcription, suggesting a potential mechanism by which RKIP inhibits tumor progression and metastasis.

Going beyond "Basaloid neoplasm": Fine needle aspiration cytology of epithelial-myoepithelial carcinoma of the parotid gland.

Epithelial‐myoepithelial carcinoma (EMC) is a rare salivary gland malignancy with variable cytologic findings. Its rarity, variable morphologic findings, and similarities with more common salivary gland entities make it a difficult cytologic diagnosis. As the name signifies, the key feature of this tumor is presence of an epithelial and myoepithelial component. However, when one of these two components is scant on the fine needle aspiration (FNA) smears, it may be overlooked. We present a case from a 62 year‐old female who presented to the clinic with a parotid nodule and episodes of sharp, throbbing pain. A fine needle aspiration was performed which revealed a highly cellular specimen comprised primarily of aggregates of cells with small, round nuclei and scant to absent cytoplasm. Abundant hyaline stromal material was also noted. The case was signed out as basaloid neoplasm with a recommendation for surgical resection. The subsequent resection specimen revealed EMC. By reviewing the FNA specimen following the surgical resection of the tumor, we were able to utilize the benefit of hindsight to more clearly identify the subtle, biphasic components of the tumor. Diagn. Cytopathol. 2016;44:422–425.

Retroperitoneal Metastatic Germ Cell Tumor Presenting as a Psoas Abscess: A Diagnostic Pitfall

Most testicular neoplasms are germ cell tumors, the vast majority of which represent seminomas. Most seminomas present localized to the testis, whereas nonseminomatous germ cell tumors more often present with lymph node metastases. Psoas abscesses generally arise from a contiguous intra-abdominal or pelvic infectious process, an adjacent focus of osteomyelitis or septic emboli from distant infectious foci. In this study, the case of a 24-year-old man who presented with a right psoas mass presumptively diagnosed as an abscess secondary to fever and leukocytosis is presented. The patient had a history of right testicular seminoma, and normal serum levels of alpha-fetoprotein and human chorionic gonadotropin. Surgical exploration and biopsy demonstrated seminoma metastasis. This case represents an extremely unusual clinical presentation of metastatic germ cell tumor presenting as a psoas abscess. This unique case represents an unusual presentation of a recurrent germ cell tumor mimicking a psoas abscess. Awareness of possible metastatic testicular germ cell neoplasm as a psoas abscess could prevent diagnosis delay before retroperitoneal tumor debulking.

Laparoscopic aspiration cytology in rheumatoid ascites: a case report.

BACKGROUND To the best of our knowledge, there are currently no recorded cytologic features of any effusion from rheumatoid peritonitis showing cytologic findings linked to rheumatoid pleural disease, although rheumatoid nodules have been described in the peritoneum. CASE A 75-year-old man with longstanding, poorly controlled rheumatoid arthritis was seen in our hospital after a motor vehicle collision. Computed tomography showed free fluid in the abdominal cavity. Laparoscopic examination revealed a large amount of nonhemorrhagic ascitic fluid and no traumatic intraabdominal injuries. Abdominal and peritoneal surfaces appeared completely normal. The ascitic fluid was aspirated through the laparoscope and sent for cytologic examination. Cytospin preparations revealed histiocytes and loosely cohesive clusters of small cytologically bland epithelioid cells amid acute inflammatory cells and granular necrotic debris. Cell block material displayed transected fibroconnective tissue fragments lined by hyperplastic mesothelium with squamous metaplasia. Immunohistochemical studies revealed that the mesothelial cells were positive for calretinin, cytokeratin 5/6, and p63. CONCLUSION The ascites was attributed to peritoneal disease from rheumatoid arthritis, based on the cytologic findings, immuno-profile, exclusion of other possible causes (i.e., cirrhosis, nephrotic syndrome, protein-losing enteropathy, or drugs), and patients clinical setting.