Pulmonary Adenocarcinoma Mimicking Pneumonia in a Young Adult.

Lung cancer is the third most common cancer in the United States. Lung adenocarcinoma is a subtype of non-small cell lung cancer. On computed tomography (CT) it can appear as ground glass nodules, consolidative opacity, or solid mass lesions located in the periphery. Because it can appear as a consolidation, it can sometimes be confused with an infectious process such as pneumonia. We present a case of a 27-year-old male initially diagnosed with pneumonia; however, three months later, when he presented to the hospital with worsening pleuritic chest pain, fever, and dyspnea after a bronchoscopy a week before admission, pathology was positive for adenocarcinoma.

An Interesting Case of Prostate Cancer Presenting With Colonic Metastasis.

Prostate cancer is common cancer that grows slowly and tends to metastasize to bones, lungs, and the liver. Most malignancies have established patterns in presentation, localization, and organs where they metastasize. We are presenting a case of a 60-year-old man who presented with abdominal pain and, on further investigation, was found to have polyps in the colon, a flat rectal mass with eccentric thickening of the rectum, a moderately enlarged prostate, and multiple liver masses suggestive of metastasis. It was initially thought to be colorectal cancer with metastasis but was eventually diagnosed as a stage IV prostate adenocarcinoma with metastases to the liver and rectum. It is very unusual for prostate cancer to present with distal metastasis to the liver and rectum, as in this case.

A Rare Case of Horseshoe Kidney With Multiple Atrial Myxomas Presenting as Cerebrovascular Accident.

Myxomas are benign tumors of mesenchymal origin, containing a few pluripotent cells in the myxomatous stroma. They usually present at 30-40 years of age and are more common in females than males. These tumors mostly arise in the atria and protrude into the atrial lumen. They cause constitutional symptoms like fever and weight loss and obstructive symptoms related to outflow obstruction in the heart. Some tumors are more fragile and cause embolism and may present as stroke. Mostly sporadic but familial cases and myxomas associated with Carney syndrome (CNC) tend to be multiple. Here, we report a case of a 40-year-old female with a stroke due to embolization from multiple myxomas. She had no family history of myxoma and had no skin findings or other tumors associated with CNC. She also had an atrophied horseshoe kidney with renal failure. The association of a horseshoe kidney with myxoma is rarely reported. In an extensive literature search, we could only find only one other case. Atrial myxomas were detected while investigating the cause of stroke. Our patient gradually improved and was advised surgical removal of the myxomas, which is the treatment of choice.

A Rare Case of Acute Calculous Cholecystitis With Gallbladder Hydrops.

Gallbladder hydrops or mucocele is usually due to the obstruction of the gallbladder by a gallstone. It is usually characterized by an increase in gallbladder volume, which remains clinically silent and is often incidentally diagnosed during exploratory laparotomy or laparoscopy. We report a rare case of acute calculous cholecystitis with gallbladder hydrops (measuring 17 cm in maximum dimension) due to the obstruction of the cystic duct by a gallstone in a 67-year-old female. We highlight the importance of early magnetic resonance imaging (MRI) in patients with right upper quadrant (RUQ) pain to rule out gallbladder hydrops especially in those with a history of gallstones.

TRIOBP-5 sculpts stereocilia rootlets and stiffens supporting cells enabling hearing.

TRIOBP remodels the cytoskeleton by forming unusually dense F-actin bundles and is implicated in human cancer, schizophrenia, and deafness. Mutations ablating human and mouse TRIOBP-4 and TRIOBP-5 isoforms are associated with profound deafness, as inner ear mechanosensory hair cells degenerate after stereocilia rootlets fail to develop. However, the mechanisms regulating formation of stereocilia rootlets by each TRIOBP isoform remain unknown. Using 3 new Triobp mouse models, we report that TRIOBP-5 is essential for thickening bundles of F-actin in rootlets, establishing their mature dimensions and for stiffening supporting cells of the auditory sensory epithelium. The coiled-coil domains of this isoform are required for reinforcement and maintenance of stereocilia rootlets. A loss of TRIOBP-5 in mouse results in dysmorphic rootlets that are abnormally thin in the cuticular plate but have increased widths and lengths within stereocilia cores, and causes progressive deafness recapitulating the human phenotype. Our study extends the current understanding of TRIOBP isoform-specific functions necessary for life-long hearing, with implications for insight into other TRIOBPopathies.

CDC14A phosphatase is essential for hearing and male fertility in mouse and human.

The Cell Division-Cycle-14 gene encodes a dual-specificity phosphatase necessary in yeast for exit from mitosis. Numerous disparate roles of vertebrate Cell Division-Cycle-14 (CDC14A) have been proposed largely based on studies of cultured cancer cells in vitro. The in vivo functions of vertebrate CDC14A are largely unknown. We generated and analyzed mutations of zebrafish and mouse CDC14A, developed a computational structural model of human CDC14A protein and report four novel truncating and three missense alleles of CDC14A in human families segregating progressive, moderate-to-profound deafness. In five of these families segregating pathogenic variants of CDC14A, deaf males are infertile, while deaf females are fertile. Several recessive mutations of mouse Cdc14a, including a CRISPR/Cas9-edited phosphatase-dead p.C278S substitution, result in substantial perinatal lethality, but survivors recapitulate the human phenotype of deafness and male infertility. CDC14A protein localizes to inner ear hair cell kinocilia, basal bodies and sound-transducing stereocilia. Auditory hair cells of postnatal Cdc14a mutants develop normally, but subsequently degenerate causing deafness. Kinocilia of germ-line mutants of mouse and zebrafish have normal lengths, which does not recapitulate the published cdc14aa knockdown morphant phenotype of short kinocilia. In mutant male mice, degeneration of seminiferous tubules and spermiation defects result in low sperm count, and abnormal sperm motility and morphology. These findings for the first time define a new monogenic syndrome of deafness and male infertility revealing an absolute requirement in vivo of vertebrate CDC14A phosphatase activity for hearing and male fertility.

Mutational Spectrum of MYO15A and the Molecular Mechanisms of DFNB3 Human Deafness.

Deafness in humans is a common neurosensory disorder and is genetically heterogeneous. Across diverse ethnic groups, mutations of MYO15A at the DFNB3 locus appear to be the third or fourth most common cause of autosomal-recessive, nonsyndromic deafness. In 49 of the 67 exons of MYO15A, there are currently 192 recessive mutations identified, including 14 novel mutations reported here. These mutations are distributed uniformly across MYO15A with one enigmatic exception; the alternatively spliced giant exon 2, encoding 1,233 residues, has 17 truncating mutations but no convincing deafness-causing missense mutations. MYO15A encodes three distinct isoform classes, one of which is 395 kDa (3,530 residues), the largest member of the myosin superfamily of molecular motors. Studies of Myo15 mouse models that recapitulate DFNB3 revealed two different pathogenic mechanisms of hearing loss. In the inner ear, myosin 15 is necessary both for the development and the long-term maintenance of stereocilia, mechanosensory sound-transducing organelles that extend from the apical surface of hair cells. The goal of this Mutation Update is to provide a comprehensive review of mutations and functions of MYO15A.

A mutation of MET, encoding hepatocyte growth factor receptor, is associated with human DFNB97 hearing loss.

BACKGROUND: Hearing loss is a heterogeneous neurosensory disorder. Mutations of 56 genes are reported to cause recessively inherited non-syndromic deafness. OBJECTIVE: We sought to identify the genetic lesion causing hearing loss segregating in a large consanguineous Pakistani family. METHODS AND RESULTS: Mutations of GJB2 and all other genes reported to underlie recessive deafness were ruled out as the cause of the phenotype in the affected members of the participating family. Homozygosity mapping with a dense array of one million SNP markers allowed us to map the gene for recessively inherited severe hearing loss to chromosome 7q31.2, defining a new deafness locus designated DFNB97 (maximum logarithm of the odds score of 4.8). Whole-exome sequencing revealed a novel missense mutation c.2521T>G (p.F841V) in MET (mesenchymal epithelial transition factor), which encodes the receptor for hepatocyte growth factor. The mutation cosegregated with the hearing loss phenotype in the family and was absent from 800 chromosomes of ethnically matched control individuals as well as from 136 602 chromosomes in public databases of nucleotide variants. Analyses by multiple prediction programmes indicated that p.F841V likely damages MET function. CONCLUSIONS: We identified a missense mutation of MET, encoding the hepatocyte growth factor receptor, as a likely cause of hearing loss in humans.

Mutations of GJB2 encoding connexin 26 contribute to non-syndromic moderate and severe hearing loss in Pakistan.

Mutations of GJB2 which encode connexin 26, contribute to 6-7 % of profound deafness in Pakistan. We investigated the involvement of GJB2 mutations in a cohort of 84 pedigrees and 86 sporadic individuals with moderate or severe hearing loss. Individuals in eight consanguineous families and four sporadic cases (9.52 and 4.65 %, respectively) were homozygous or compound heterozygous for p.W24X or p.W77X mutations in GJB2. These two variants are also among the most common mutations known to cause profound deafness in South Asia. The association of identical mutations with both profound and less severe phenotype of hearing loss suggests that alleles of other genes modify the phenotype due to these GJB2 nonsense mutations. Our study demonstrates that GJB2 mutations are an important contributor to aetiology of moderate to severe hearing loss in Pakistan.

A frameshift mutation in GRXCR2 causes recessively inherited hearing loss.

More than 360 million humans are affected with some degree of hearing loss, either early or later in life. A genetic cause for the disorder is present in a majority of the cases. We mapped a locus (DFNB101) for hearing loss in humans to chromosome 5q in a consanguineous Pakistani family. Exome sequencing revealed an insertion mutation in GRXCR2 as the cause of moderate-to-severe and likely progressive hearing loss in the affected individuals of the family. The frameshift mutation is predicted to affect a conserved, cysteine-rich region of GRXCR2, and to result in an abnormal extension of the C-terminus. Functional studies by cell transfections demonstrated that the mutant protein is unstable and mislocalized relative to wild-type GRXCR2, consistent with a loss-of-function mutation. Targeted disruption of Grxcr2 is concurrently reported to cause hearing loss in mice. The structural abnormalities in this animal model suggest a role for GRXCR2 in the development of stereocilia bundles, specialized structures on the apical surface of sensory cells in the cochlea that are critical for sound detection. Our results indicate that GRXCR2 should be considered in differential genetic diagnosis for individuals with early onset, moderate-to-severe and progressive hearing loss.