Paucity Of Fat Research Articles

Sclerosing well-differentiated liposarcoma: two diagnostically challenging mimicker cases and a literature review.

Liposarcoma is a malignant soft tissue tumor with several subtypes, the most common of which is well-differentiated liposarcoma (WDL) or atypical lipomatous tumor (ALT). WDL/ALTs are further divided into three histological subtypes, including lipoma-like, sclerosing, andinflammatory. While the majority of these tumors are predominantly fatty, the sclerosing variant demonstrates diverse histologic and radiographic characteristics, including variable amounts of fibrosis and fat. Because of this histological variability and relative rarity, the sclerosing WDL/ALT can present diagnostic dilemmas. We present two cases of sclerosing WDL/ALT, both of which demonstrated high degrees of fibrosis and a paucity of fat, mimicking desmoid fibromatosis and other fibrotic soft tissue tumors. Thus, it is important for radiologists to be aware of the subtypes of liposarcoma and their unique characteristics, and to consider sclerosing WDL/ALT in cases of fibrotic soft tissue tumors.

The utility of angioembolisation prior to surgery in a highly vascular renal tumour

Epithelioid angiomyolipoma is a rare variant of renal tumour with potential for aggressive biological profile. We present a12 year old girl with a large angiomyolipoma that created diagnostic and treatment difficulty and review this condition. A 12 year old girl presented with right flank pain. Imaging discovered a large mass arising from the upper pole of the right kidney but inseparable from the adrenal gland and under-surface of the liver. The lesion was highly vascular with a very large draining vein into the renal vein, initially precluding safe needle biopsy. MRI showed small component of fat. A provisional diagnosis of angiomylipoma was made. There was no systemic evidence of tuberous sclerosis. The patient required multiple episodes of embolization to enable safe biopsy as there was diffuse dysplastic and aneurysmal arterial supply from renal, adrenal, phrenic, lumbar and hepatic arteries. Biopsy was performed percutaneously with a balloon in the renal artery. Histology confirmed epithelioid angiomyolipoma. Further sequential embolization was performed to devascularise the tumour prior the surgery. The patient was able to undergo a partial nephrectomy with virtually no blood loss. Epithelioid angiomyolipoma is a rare variant of angiomyolipoma which has been described to have a more aggressive course in some patients. They tend to be larger lesions. The paucity of fat in our patient made imaging diagnosis doubtful. Embolization not only made biopsy safer but also facilitated a safe partial resection of the affected kidney. Histology confirmed the initial diagnosis with complete resection of the lesion. Epithelioid angiomyolipoma defines a group of tumours that are not potentially malignant. This case shows that biopsy of vascular lesions and renal sparing surgery is possible and safe when combined with pre-operative embolization. We highlight the role of pre-operative embolization to avoid haemorrhage and facilitate safe dissection of operative planes.

Insulin Receptor and the Kidney: Nephrocalcinosis in Patients with Recessive INSR Mutations

Background/Aims: Donohue and Rabson-Mendenhall syndrome are rare autosomal recessive disorders caused by mutations in the insulin receptor gene, INSR. Phenotypic features include extreme insulin resistance, linear growth retardation, paucity of fat and muscle, and soft tissue overgrowth. The insulin receptor is also expressed in the kidney, where animal data suggest it plays a role in glomerular function and blood pressure (BP) regulation, yet such a role in the human kidney is untested. Patients with biallelic INSR mutations provide a rare opportunity to ascertain its role in man. Methods: Retrospective review of patients with INSR mutations. Data for BP, renal imaging, plasma creatinine and electrolyte levels, as well as urine protein, albumin and calcium excretion were sought from the treating clinicians. Results: From 33 patients with INSR mutations, data were available for 17 patients. Plasma creatinine was low (mean ± SD: 25 ± 9 μmol/l) and mean plasma electrolyte concentrations were within the normal range (n = 13). Systolic BP ranged between the 18th and 91st percentile for age, sex, height and weight (n = 9; mean ± SD: 49 ± 24). Twenty-four-hour urinary calcium data were available from 10 patients and revealed hypercalciuria in all (mean ± SD: 0.32 ± 0.17 mmol/kg/day; normal <0.1). Nephrocalcinosis was present in all patients (n = 17). Urinary albumin excretion (n = 7) ranged from 4.3-122.5 μg/min (mean ± SD: 32.4 ± 41.0 μg/min; normal <20). Conclusions: INSR dysfunction is associated with hypercalciuria and nephrocalcinosis. No other consistent abnormality of renal function was noted. Normotension and stable glomerular function with only moderate proteinuria is in contrast to genetically modified mice who have elevated BP and progressive diabetic nephropathy.

LMNA gene mutation as a model of cardiometabolic dysfunction: From genetic analysis to treatment response

AimThis report highlights the metabolic, endocrine and cardiovascular comorbidities in a case of familial partial lipodystrophy (FPLD), and also evaluates the efficacy and safety of metformin therapy. MethodsMutational analysis was carried out of the LMNA gene in a teenage girl with an FPLD phenotype. Insulin resistance, sex hormones and metabolic parameters were also evaluated, and echocardiography, electrocardiography and 24-h blood pressure monitoring were also done. ResultsThe patient showed atypical fat distribution, insulin resistance and hypertrophic cardiomyopathy. Physical examination revealed muscle hypertrophy with a paucity of fat in the extremities, trunk and gluteal regions, yet excess fat deposits in the face, neck and dorsal cervical region. LMNA sequencing revealed a heterozygous missense mutation (c.1543A>G) in exon 9, leading to substitution of lysine by glutamic acid at position 515 (K515E). Moderate hypertension and secondary polycystic ovary syndrome were also assessed. Treatment with metformin resulted in progressive improvement of metabolic status, while blood pressure values normalized with atenolol therapy. ConclusionsVery rapid and good results with no side-effects were achieved with metformin therapy for FPLD. The association of an unusual mutation in the LMNA gene was also described.

PIK3R1 Mutations Cause Syndromic Insulin Resistance with Lipoatrophy

Short stature, hyperextensibility of joints and/or inguinal hernia, ocular depression, Rieger anomaly, and teething delay (SHORT) syndrome is a developmental disorder with an unknown genetic cause and hallmarks that include insulin resistance and lack of subcutaneous fat. We ascertained two unrelated individuals with SHORT syndrome, hypothesized that the observed phenotype was most likely due to de novo mutations in the same gene, and performed whole-exome sequencing in the two probands and their unaffected parents. We then confirmed our initial observations in four other subjects with SHORT syndrome from three families, as well as 14 unrelated subjects presenting with syndromic insulin resistance and/or generalized lipoatrophy associated with dysmorphic features and growth retardation. Overall, we identified in nine affected individuals from eight families de novo or inherited PIK3R1 mutations, including a mutational hotspot (c.1945C>T [p.Arg649Trp]) present in four families. PIK3R1 encodes the p85α, p55α, and p50α regulatory subunits of class IA phosphatidylinositol 3 kinases (PI3Ks), which are known to play a key role in insulin signaling. Functional data from fibroblasts derived from individuals with PIK3R1 mutations showed severe insulin resistance for both proximal and distal PI3K-dependent signaling. Our findings extend the genetic causes of severe insulin-resistance syndromes and provide important information with respect to the function of PIK3R1 in normal development and its role in human diseases, including growth delay, Rieger anomaly and other ocular affections, insulin resistance, diabetes, paucity of fat, and ovarian cysts.

Lipodystrophy of HIV (LDHIV) in the Head and Neck: Imaging and Clinical Features

A subset of HIV-1 infected patients undergoing antiretroviral treatment with HIV-1 protease inhibitors (PI’s) develops a syndrome called Lipodystrophy of HIV (LDHIV). LDHIV is characterized by loss of peripheral subcutaneous adipose tissue (face, limbs, buttocks), visceral fat accumulation, and in some cases, lipomatosis in the neck and dorsocervical area .We describe the clinical and imaging features of LDHIV in the head and neck in a series of 5 cases. There is a consistent pattern of fat accumulation in the dorsocervical region with paucity of fat in the face. This classic appearance should be recognized as potentially related to drug toxicity in the HIV infected population.

Updated Protocol for the Examination of Specimens From Patients With Carcinomas of the Prostate Gland

T protocol is intended to assist pathologists in providing clinically useful and relevant information as a result of the examination of surgical specimens. Use of this protocol is intended to be entirely voluntary. If equally valid protocols or similar documents are applicable, the pathologist is, of course, free to follow those authorities. Indeed, the ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of the individual circumstances presented by a specific patient or specimen. It should be understood that adherence to this protocol will not guarantee a successful result. Nevertheless, pathologists are urged to familiarize themselves with the document. Should a physician choose to deviate from the protocol based on the circumstances of a particular patient or specimen, the physician is advised to make a contemporaneous written notation of the reason for the procedure followed. The College recognizes that this document may be used by hospitals, attorneys, managed care organizations, insurance carriers, and other payers. However, the document was developed solely as a tool to assist pathologists in the diagnostic process by providing information that reflects the state of relevant medical knowledge at the time the protocol was first published. It was not developed for credentialing, litigation, or reimbursement purposes. The College cautions that any uses of the protocol for these purposes involve considerations that are beyond the scope of this document.

The nonvisualized appendix: incidence of acute appendicitis when secondary inflammatory changes are absent.

The objective of our study was to assess the importance of nonvisualization of the appendix and its association with acute appendicitis on helical CT when secondary inflammatory changes are absent. After we received institutional review board approval, CT scans of 366 consecutive patients obtained for lower abdominal or right lower quadrant pain and to rule out appendicitis were retrospectively reviewed. Images were reviewed by an experienced abdominal radiologist and compared with the formal interpretation. The amount of right lower quadrant and pericecal fat was quantified on a scale of 0 (none) to 2 (abundant). Patients with a nonvisualized appendix and other findings compatible with acute appendicitis-such as abscess formation, localized perforation, periappendiceal fat stranding, or appendicolith-were excluded. The appendix could not be visualized by both reviewers in 46 (13%) of 366 cases. CT findings indicated another cause for the patient's symptoms in 12 cases (26%), including gastrointestinal and genitourinary processes. An alternate diagnosis was subsequently reached in 11 additional patients (24%) with follow-up imaging or clinical evaluation. Only one patient (2%) with a nonvisualized appendix had acute appendicitis, proven by surgical pathology. In this patient, there was paucity of fat in the right lower quadrant. In the absence of a distinctly visualized appendix and secondary inflammatory changes, the incidence of acute appendicitis is low. Nonvisualization of the appendix even when a small amount of fat is present in the right lower quadrant may safely exclude acute appendicitis if no secondary CT findings are present.

Lipoatrophic diabetes and other related syndromes.

Millions of Americans are afflicted by obesity and type 2 diabetes mellitus. Obesity is characterized by increased body adiposity and leads to insulin resistance. Paradoxically, some conditions that are characterized by a paucity of fat also cause insulin resistance, namely the syndromes of lipoatrophy (Fig. 1). The resemblance between the metabolic abnormalities of these two extreme states of adiposity emphasizes the importance of fat tissue in energy homeostasis. This review focuses on the syndromes of lipodystrophy and lipoatrophy that are at the lean extreme of the spectrum and which are characterized by near-complete absence of fat.

MR IMAGING OF MUSCULOSKELETAL TUMORS IN THE ELBOW REGION

MR imaging is useful in the evaluation of benign and malignant osseous and soft-tissue masses in the elbow. It allows for multiplanar, high-contrast images that provide precise definition of local tumor extent. The paucity of fat and a high concentration of small soft-tissue structures such as tendons, ligaments, and nerves in this area makes MR imaging more advantageous than CT for delineating tumor margins in the soft tissue. This article describes some of the more common tumors around the elbow with emphasis on their MR imaging characteristics.

Gallbladder carcinoma: evaluation with MR imaging.

Magnetic resonance (MR) images of 19 patients with histologically proved gallbladder carcinoma were retrospectively reviewed to determine the appearance of the primary tumor, and to assess the ability of MR imaging to demonstrate the various modes of tumor spread beyond the gallbladder. The primary tumor, as well as tumor spread beyond the gallbladder, was hyperintense on T2-weighted images and hypointense on T1-weighted images when compared with the liver parenchyma. Liver invasion and metastasis could be depicted by MR imaging with both sequences, unless the tumors were small or the extent of invasion was minimal. Duodenal invasion was difficult to evaluate because of motion artifacts, paucity of fat, and partial volume effects. T1-weighted images readily demonstrated extension of the tumor to the hepatoduodenal ligament and para-aortic region with good contrast between tumor and surrounding tissue. The extent of tumor extension to the blood vessels was also easily evaluated because of flow void in the vasculature. MR imaging can help determine the extent of gallbladder carcinoma and can contribute to the staging of this disease.

The behavior of fat-soluble dyes in the organism

It is well known that the fat-soluble dye, Sudan III., is readily deposited in the adipose tissue of animals. An attempt was made by the authors to study the movements of the dye under conditions where fat transport takes place (e. g., in starvation, phlorhizinand phosphorus poisoning). The dye readily migrates into the blood with the fat under these conditions, but is rarely found in the liver tissue into which large quantities of fat enter (fatty infiltration). This is explained by the observation that the Sudan III. is abundantly excreted with the bile into the intestine from which it may be reabsorbed. Sudan III., which is insoluble in water, is not excreted through the kidneys except where alimentary lipuria is induced (in rabbits and rats). The elimination from the liver is not accomplished through the solvent medium of fat excreted in the bile (lipocholia); but the dye is soluble in bile as well as in solution of the isolated bile salts. We have thus established a path of elimination for fat-soluble (or bile-soluble) substances through the biliary secretion. An investigation of a considerable number of water-insoluble, fat-soluble compounds—mostly nontoxic aniline dyes and food colors—showed comparable conditions justifying the above general conclusion. It has further been established that these water-insoluble compounds do not experience absorption from the intestine in the absence of bile. Dissolved in fat-emulsion and introduced into the organism by alimentary, subcutaneous, or intravenous paths, these dyes are always eliminated with the bile into the intestine. When there is a paucity of fat in the diet the fat-soluble dyes may be absorbed through the agency of reabsorbed bile, but they are speedily eliminated again by the liver channels; with an abundance of fat to act as carrier, they travel with it through the lymphatics into the circulation.