Appendicular Lesions Research Articles

Clinicopathological Study of Lesions of Upper Gastrointestinal Tract

62 sections of the GIT tract were used in this study. It was possible to get biopsies from the esophagus, mouth, stomach, duodenum, liver, small intestine, colon, rectum, and anal canal. Most of the specimens came from people aged 21 to 30 (24), then from people aged 11 to 20 (16), 31 to 40 (10), 41 to 50 (8), and older than 50 (4). There were 50 tumors that were not cancerous and 12 that were. Most of the non-cancerous tumors were found in the gall bladder, then the stomach, and finally the small intestine. The gall bladder was the organ most often affected by cancerous tumors (5), followed by the stomach. Chronic inflammatory lesions of the esophagus were seen in 10, appendicular lesions were seen in 3, gall bladder lesions were seen in 26, intestinal perforation was seen in 4, Crohn's disease of the small intestine was seen in 5, and peptic ulcers were seen in 2. Three of the cases had SCC of the esophagus, one had adenocarcinoma of the small intestine, one had adenocarcinoma of the large intestine, two had SCC of the stomach, and five had adenoma of the gall bladder. The authors found that most of the non-cancerous tumors were in the gall bladder and were found in people aged 21 to 30.
 Keywords: Gastrointestinal tract, neoplastic lesions, Gall bladder.

Denosumab administration for bone metastases from solid tumors: a retrospective cross-sectional study

BackgroundLittle is known on how denosumab reduces skeletal-related events (SREs) by bone metastases from solid tumors. We sought to evaluate the effect of denosumab administration in patients with bone metastases from solid tumors.MethodsData of patients treated with denosumab were collected from electronic medical charts (n = 496). Eligible participants in this study were adult patients (age ≥ 18 years) with metastatic bone lesions from solid tumors treated with denosumab. SREs, surgical interventions, the spinal instability neoplastic score (SINS) for spinal region, and Mirels’ score for the appendicular region were evaluated. To assess whether denosumab could prevent SREs and associated surgery, the SINS and Mirels’ score were compared between patients with and without SREs.ResultsA total of 247 patients (median age, 65.5 years old; median follow-up period, 13 months) treated with denosumab for metastatic bone lesions from solid tumors were enrolled in this study. SREs occurred in 19 patients (7.7%). SREs occurred in 2 patients (0.8%) who took denosumab administration before SREs. Surgical interventions were undertaken in 14 patients (5.7%) (spinal and intradural lesions in five patients and appendicular lesions in nine patients). The mean SINS of patients without SREs compared to those with SREs were 7.5 points and 10.2 points, respectively. The mean Mirels’ scores of non-SREs patients and those with SREs were 8.07 points and 10.7 points, respectively. Patients with SREs had significantly higher Mirels’ score than non-SREs patients (p < 0.01). Patients with SREs had higher SINS than non-SREs patients (p = 0.09).ConclusionsSREs occurred in patients with higher SINS or Mirels’ scores. Two patients suffered from SREs though they took denosumab administration before SREs. Appropriate management of denosumab for patients with bone metastasis is significant. Surgical interventions may be needed for patients who with higher SINS or Mirel’s scores.

Endoscopic submucosal dissection of appendicular lesions is feasible and safe: a retrospective multicenter study (with video)

Endoscopic submucosal dissection (ESD) is challenging for appendicular lesions. We report the outcomes of ESD in this context. We collected data of ESD procedures for appendiceal neoplasia in a multicenter prospective registry. Main study endpoints were R0, en-bloc, and curative resection rates and adverse event rate. One hundred twelve patients were included, 47 (42%) with previous appendectomy. Fifty-six (50%) were Toyonaga type 3 lesions (15 [13.4%] postappendectomy). En-bloc and R0 resection rates were 86.6% and 80.4%, respectively, with no significant difference associated with different grades of appendiceal invasion (P= .9 and P= .4, respectively) or previous appendectomy (P= .3 for both). The curative resection rate was 78.6%. Additional surgery was performed in 16 cases (14.3%), including 10 (62.5%) Toyonaga type 3 lesions (P= .04). This included the treatment of 5 cases (4.5%) of delayed perforation and 1 acute appendicitis. ESD for appendicular lesions is a potentially safer and effective alternative to surgery for a significant proportion of patients.

DOES THE HISTOLOGICAL PRESENCE OF A NIDUS CORRELATE WITH IMPROVED OUTCOMES IN OSTEOID OSTEOMA TREATED WITH PERCUTANEOUS RADIOFREQUENCY ABLATION (RFA)?

The primary aim of this study was to compare the clinical outcomes of osteoid osteoma (OO) between the group of patients with the presence of nidus on biopsy samples from radiofrequency ablation (RFA) with those without nidus. Secondly, we aimed to examine other factors that may affect the outcomes of OO reflecting our experience as a tertiary orthopaedic oncology centre.We retrospectively reviewed 88 consecutive patients diagnosed with OO treated with RFA between November 2005 and March 2015, consisting of 63 males (72%) and 25 females (28%). Sixty-six patients (75%) had nidus present in their biopsy samples. Patients’ mean age was 17.6 years (4-53). Median duration of follow-up was 12.5 months (6-20.8). Lesions were located in the appendicular skeleton in seventy-nine patients (90%) while nine patients (10%) had an OO in the axial skeleton. Outcomes assessed were based on patients’ pain alleviation (partial, complete, or no pain improvement) and the need for further interventions.Pain improvement in the patient group with nidus in histology sample was significantly better than the group without nidus (OR 7.4, CI 1.35-41.4, p=0.021). The patient group with nidus on biopsy demonstrated less likelihood of having a repeat procedure compared to the group without nidus (OR 0.092, CI 0.016-0.542, p=0.008). Our study showed significantly better outcomes in pain improvement in appendicular lesions compared to the axially located lesions (p = 0.005). Patients with spinal lesions tend to have relatively poor pain relief than those with appendicular or pelvic lesions (p=0.007).Patients with nidus on histology had better pain alleviation compared to patients without nidus. The histological presence of nidus significantly reduces the chance of repeat interventions. The pain alleviation of OO following RFA is better in patients with appendicular lesions than spinal or axially located lesions.

Endoscopic full-thickness resection of two appendicular lesions: hybrid and conventional approaches.

Endoscopic full-thickness resection of two appendicular lesions: hybrid and conventional approaches.

Histopathological examination of cases with acute appendicitis, A retrospective study at King Abdulaziz University Hospital, Jeddah, Saudi Arabia

IntroductionAppendicitis is one of the most prevalent abdominal emergencies globally. Despite the fact that acute appendicitis is a clinical diagnosis, preoperative imaging investigations are often conducted. Other disorders that might mimic acute appendicitis can occur in the appendix. The aim of this paper is to describe the histopathological findings of all appendectomy specimens. MethodsA retrospective study of 940 cases of appendectomy that were performed between 2010 and 2017 at King Abdulaziz University Hospital, Jeddah, Saudi Arabia were reviewed. The main outcome measured in this study is to describe the histopathological findings of all appendectomy specimens. The secondary outcomes measured in this study were the disease incidence in relation to age, and gender. Moreover, the accuracy of imaging diagnostic tools were also evaluated. ResultsThis study included 940 participants who underwent an appendectomy procedure. The patients' mean age was 23.4 years (±12.2), with a 3:2 male to female proportion. The incidence in males and females were 59.4% and 40.6%, respectively. Being male (p < 0.001), undergoing preoperative ultrasound (p < 0.001), having elevated white blood cells count (p < 0.001) was significantly associated with accurate diagnosis of acute appendicitis confirmed by histopathology. In this study, the negative cases of appendectomy that account for 14.4% were reported primarily as normal appendix with no inflammatory changes (7.44%) followed by other unexpected findings in the appendectomy specimen (3.93%) that included faecolith, granulomas, mucocele, endometriosis, food/fecal impaction, and schistosomiasis. Our study showed CT sensitivity as a diagnostic tool of acute appendicitis is 90.2%, and its accuracy is 89.4%, while US sensitivity is 46% and its accuracy is 52.4%. ConclusionHistopathological evaluation after common procedures, such as appendectomy, is essential to avoid missing other pathologies in the appendix. Surgeons should be aware of the uncommon histopathology findings as some disorders call for additional management beyond appendectomy. The clinical details, radiological investigations including CT scan and histopathological diagnoses are required for better management in cases of appendicular lesions.

Clinical features, treatment, and outcome of dogs with Coccidioides osteomyelitis.

To describe signalment, clinical signs, serologic test results, treatment, and outcome of dogs with Coccidioides osteomyelitis (COM) and to compare those findings with findings for dogs with osteosarcoma (OSA). 14 dogs with COM and 16 dogs with OSA. Data were retrospectively gathered from electronic medical records. Dogs with COM were younger and weighed less than dogs with OSA. Six dogs with COM had appendicular lesions, 5 had axial lesions, and 3 had both appendicular and axial lesions; 9 had monostotic disease, and 5 had polyostotic disease. Axial lesions and nonadjacent polyostotic disease were more common in dogs with COM than in dogs with OSA, but radiographic appearance was not different between the 2 groups. Median IgG titer at diagnosis of COM was 1:48 and was significantly decreased after 6 and 12 months of treatment. Percentage of dogs with COM that had clinical signs was significantly decreased after 1, 3, 6, and 12 months of treatment. One year after initiation of treatment, 9 of 9 dogs were still receiving fluconazole and 8 of 9 dogs had positive results for serum IgG titer testing. Dogs with COM typically had a rapid improvement in clinical signs after initiating treatment with fluconazole but required long-term antifungal treatment. Dogs with COM differed from dogs with OSA, but radiographic features had a great degree of overlap between groups, confounding the ability to make a diagnosis on the basis of diagnostic imaging alone.

Magnetic resonance imaging findings of synovial sarcoma in children: location-dependent differences.

While overall survival for children is greater than that for adults, synovial sarcoma remains an aggressive neoplasm with a potentially poor prognosis, and its magnetic resonance imaging (MRI) findings in children are not well described. We aimed to characterize the spectrum of MRI findings of synovial sarcoma in children with respect to anatomical location and outcome. Children with histologically confirmed synovial sarcoma and preoperative MRI performed within the past 11years (2009-2020) were included. Two radiologists retrospectively reviewed each MRI to categorize location, signal characteristics and associated findings. Chi-square and Fisher exact tests were used to assess associations with locations and outcomes. This study included 23 children (13 girls, 10 boys; mean age: 12.7±4.2years) with 7 axial, 8 proximal and 8 distal appendicular lesions. Kappa ranged from 0.53 to 1. MRI findings differed significantly between locations with axial lesions measuring larger (P=0.01) and more likely to contain fluid levels (P=0.02), triple sign (P=0.02), inhomogeneous signal (T1-weighted images, P=0.003; T2-weighted images, P=0.02, contrast-enhanced images, P=0.03) with all lesions containing partially solid composition (P=0.03). At a median follow-up of 14months (interquartile range: 7-33months), 39% relapsed. Predictors of relapse (P<0.05) included metastasis at presentation, larger lesions, axial lesions and MRI findings of fluid level, T1-weighted hyperintensity, inhomogeneous signal (T1- and T2-weighted images) and poorly circumscribed margins. A significant association was found between location and MRI findings in our cohort of children with synovial sarcoma. Axial lesions were more likely to be larger, appear heterogeneous and be associated with a worse outcome.

Molecular profiling of appendiceal serrated lesions, polyps and mucinous neoplasms: a single-centre experience

PurposeNon-neuroendocrine neoplasms of the appendix are a phenotypically heterogeneous group of lesions; a comprehensive molecular characterization of these tumors is still lacking.MethodsA total of 52 samples taken from 49 patients was evaluated: 18 sessile serrated lesions (SSL; 3 with dysplasia), 2 high-grade tubular adenomas, 1 tubulo-villous adenoma,1 hyperplastic polyp, 18 low-grade appendiceal mucinous neoplasms (LAMN), 3 high-grade appendiceal mucinous neoplasms (HAMN) and 9 mucinous adenocarcinomas. Hotspot mutational profiling of the RNF43, SMAD4, KRAS, NRAS, BRAF and PIK3CA genes was performed. Expression of p53, MLH1, PMS2, MSH2, and MSH6 was evaluated by immunohistochemistry.ResultsKRAS was the most frequently mutated gene (53.9% of cases), followed by RNF43 (15.4%), and BRAF (13.5%). In particular: KRAS was mutated in 44.4% of adenocarcinomas, 66.7% of HAMNs, 61.1% of LAMNs, 53.3% of SSL without dysplasia and in 66.7% of SSL with dysplasia; RNF43 was mutated in 33.3% of adenocarcinomas, 66.7% of HAMNs, 11.1% of LAMNs and in 6.7% of SSL without dysplasia; BRAF was mutated in 11.1% of adenocarcinomas, 26.7% of SSL without dysplasia and in 5.6% of LAMNs. Only a case of high-grade tubular adenoma showed mismatch repair deficiency, while immunohistochemical expression of p53 was altered in 21.1% of cases.ConclusionsThe histological phenotypic similarities between appendicular mucinous lesions and serrated colon lesions do not reflect a similar genetic landscape. Mismatch repair deficiency is a rare event during appendiceal mucinous carcinogenesis.

Correlation with Age, Sex and Histo-Pathological Spectrum of Appendicular Lesions

Correlation with Age, Sex and Histo-Pathological Spectrum of Appendicular Lesions

Study of mast cell and eosinophil count in surgically resected appendix

Introduction: Appendix is a normal true diverticulum of the caecum that is prone to acute and chronic inflammation. Mast cells are present in chronic inflammatory reactions and they secrete cytokines that promote inflammation. Eosinophils are abundant in immune reactions mediated by IgE and in parasitic infection. Objective: To evaluate mast cell and eosinophil count variation in appendicitis and to suggest their possible role in pathogenesis of appendicitis. Materials and Methods: It is a two-year prospective study done on 470 resected specimens of appendices received for histopathology. Results: Mast cells and eosinophils were present in all the appendicular lesions studied. Mean mast cell count was highest in chronic appendicitis and lowest in acute appendicitis. Mucosa of chronic appendicitis showed highest count, lowest was seen in the muscularis propria of acute appendicitis compared to normal / unremarkable appendix taken as controls. Correlation between mast cell density, fibrosis and neural ganglia hypertrophy was seen in chronic appendicitis. Mean eosinophil count was highest in acute suppurative appendicitis and lowest in chronic appendicitis, with highest count in the mucosa of acute suppurative appendicitis and lowest in the muscularis propria of chronic appendicitis. Conclusion: The presence of mast cells and eosinophils in cases of appendicitis supports the allergic theory of appendicitis in which the Type I hypersensitivity reaction leads to recruitment of eosinophils and discharge of primary and secondary mediators of inflammation by degranulation of mast cells which play a role in pathogenesis of appendicitis.

Fine needle aspiration of canine appendicular bone lesions

Canine appendicular bone lesions are relatively commonly encountered in small animal practice, and a presumptive diagnosis of malignant bone tumour can be made based on signalment, history, physical examination findings, and radiographic changes. Histopathological evaluation is often recommended prior to making decisions involving aggressive treatment. However, obtaining bone biopsies is not without significant disadvantages, and fine needle aspiration (FNA) offers important benefits. Cytology from a FNA has been reported to have similar accuracy to histology (correctly identifying 27–100% of benign and 83.3–92% of malignant lesions) and its use should be considered to help guide treatment decisions in affected dogs.

Immune Surveillance Plays a Role in Locally Aggressive Giant Cell Lesions of Bone.

Giant cell lesions are locally aggressive intraosseous neoplasms with capacity to metastasize. The role of immune surveillance in the pathophysiology of giant cell lesions is poorly understood, and understanding what role the immune system plays in giant cell lesions may lead to the development of more effective treatment. The aim of this study was to explore the role of immune surveillance in giant cell lesions by examining the expression of the HLA class I and class II antigens and tumor infiltrating lymphocytes. In addition, we examined the role of the immune modulating surface antigen B7-H3, which belongs to the B7 superfamily, a group of molecules that modulates T-cell responses. (1) Is an immune response elicited by giant cell lesions? (2) Do clinically relevant human leukocyte antigen (HLA) defects exist in giant cell lesions? (3) Is B7-H3 a clinically relevant immune modulator? The study sample was derived from the population of patients presenting to the Massachusetts General Hospital for evaluation and management of giant cell lesions from 1993 to 2008. We included patients with histologically confirmed giant cell lesions with a minimum followup of 6months. Patients with systemic diseases (n = 4 [3%]), syndromes associated with giant cell lesions (n = 4 [3%]), and those without sufficient followup (n = 26 [19%]), inadequate records (n = 7 [5%]), or inadequate tissue available (n = 2 [1%]) were excluded. Tissue microarray, containing 288 tissue cores for 93 patients, was carefully constructed. This contained tissue from 45 patients with maxillofacial lesions, 38 with aggressive and seven with nonaggressive lesions, and 48 patients with axial and appendicular lesions, 30 with aggressive lesions and 18 with nonaggressive lesions. The population mean age was 28 ± 12years and the duration of followup was 4 ± 3years. The tissue microarray was immunohistochemically stained with monoclonal antibodies specific for HLA classes I and II and B7-H3 antigens and analyzed for tumor infiltrating lymphocytes. Antigen expression was examined in multinucleated giant cells and mononuclear stromal cells. The results were correlated with local invasion and tumor aggressiveness, which is based on accepted staging criteria. Tumor infiltrating lymphocytes were detected in all the tumors. The mean number of CD8+ T cell infiltration was lower in aggressive tumors (median, 4.8; interquartile range [IQR], 0.4-13.4), when compared with nonaggressive tumors (median, 15.8; IQR, 4.3-46.3; p = 0.007). HLA class I antigens were highly expressed by multinucleated giant cells in all tumors, but were lightly expressed on mononuclear stromal cells in 53% (45 of 84) to 73% (56 of 77) of tumors. HLA class I antigen low expression in mononuclear stromal cells was associated with tumor aggressiveness (odds ratio [OR], 4.3; p = 0.005). Low HLA class I expression combined with low CD8+ T cell infiltration was most highly associated with tumor aggressiveness (OR, 7.81; p = 0.011). B7-H3 antigen was expressed in 36.9% mononuclear stroma cells and also was associated with local tumor invasion (OR, 1.36; p < 0.001). Similarly, giant cell lesions with high B7-H3 expression and low CD8+ tumor infiltrating lymphocytes were associated with increased tumor aggressiveness (OR, 8.89; p = 0.0491). Locally aggressive giant cell lesions are associated with low HLA class 1 antigen expression, low CD8+T cell infiltration, and high expression of the immune modulator B7-H3. Failure of immune surveillance implies that there may be an opportunity to target aspects of the immune surveillance machinery to treat giant cell lesions.

Bone Scintigraphy in Children With Cat Scratch Disease

The objective of this study was to evaluate the degree and incidence of bone involvement in patients with cat scratch disease. Patients admitted between 2004 and 2011 at the pediatric department for cat scratch disease and a positive serology for Bartonella henselae were identified. Only those having undergone a bone scintigraphy (BS) were included in this retrospective study. Sixteen girls and 8 boys with a mean age of 7 years were studied. Bone scintigraphy was positive in 6 (25%), but only 2 had bone pain. Axial involvement was present in all 6 patients, and appendicular lesions in 3 of them. Three patients had a BS control, with improvement or normalization after treatment with antibiotics. Bone involvement occurs infrequently in patients with cat scratch disease and is not always associated with specific signs. Cat scratch disease must be suspected in patients with fever of unknown origin presenting multifocal lesions on BS.

Impact of Telomerase Status on Canine Osteosarcoma Patients

We demonstrated previously that canine osteosarcoma (OSA) cell lines and samples from clinical patients are predominantly telomerase positive. In contrast, the majority of OSA samples from human patients appear to be telomerase negative, maintaining telomere length by an alternative lengthening of telomeres (ALT) mechanism. The purpose of the current study was to examine the telomerase status of a large number of OSA samples from dogs and determine if telomerase status can serve as a prognostic factor. The majority of clinical canine OSA appendicular lesions will be telomerase positive, and telomerase positivity will negatively impact disease outcome. Sixty-seven dogs with appendicular OSA presenting to the Colorado State University Animal Cancer Center for treatment. The Telomeric Repeat Amplification Protocol was performed on tissue samples from primary canine appendicular OSA to determine the presence of telomerase activity. Telomere restriction fragment (TRF) analysis was utilized to determine telomere length and detect ALT. Outcome data were obtained in a retrospective manner and correlated with telomerase status. Seventy-three percent of canine OSA samples were telomerase positive. Telomerase status did not have an impact on disease-free interval or survival time. Nine of 10 telomerase-negative samples examined were consistent with an ALT phenotype, based on TRF analysis. These results are consistent with the hypothesis that the majority of canine OSA are telomerase positive, suggesting that telomerase may be a valuable target for canine OSA therapy. Additionally, telomerase status does not appear to be a prognostic factor in canine OSA.

Solitary plasmacytoma: Is radiation therapy sufficient?

Solitary plasmacytoma: Is radiation therapy sufficient?

AGE-INDEPENDENT OSTEOPATHOLOGY IN SKELETONS OF A SOUTH AMERICAN CERVID, THE PATAGONIAN HUEMUL (HIPPOCAMELUS BISULCUS)

The huemul (Hippocamelus bisulcus), an endemic Patagonian deer, has been endangered for decades. Although conservation in Argentina has been directed at the 350-600 remaining huemul, the population has not recovered. In initial studies on the potential effects of diseases on huemul population dynamics, skeletal remains collected between 1993 and 2007 in the Andes (41-45 degrees S, 71.5-72 degrees W) were examined macroscopically for osteopathologic changes. Bones from six huemul were free of lesions, findings were inconclusive in 13 huemul with less than three bones, and osteopathologic processes were detected in 13 adults. Considering the limited remains/case, the prevalence of osteopathy (52%) among adults probably is conservative; 63% showed mandibular, 100% maxillary, and 78% appendicular lesions. Although predation represented the actual cause of death, the observed skeletal lesions would affect predator avoidance, possibly explaining the low average adult age (3.1 yr) and lack of population recovery. Compared with other studies in ungulates, huemul were affected at a younger age, and they had more severe pathologic changes. Due to the chronic nature of disease, low huemul population density, physiognomy, and spatiotemporal pattern of lesions, we discard senescence; gender; fulminating infections; congenital anomalies; metabolic, endocrine, genetic, or neurologic disorders; parasitism or marasmus; and fluorosis as primary etiologic factors. We hypothesize that generalized secondary chronic alveolar osteomyelitis and osteoarthritis in huemul is related to the nutritional ecology of these animals. Selenium deficiency, which impairs bone metabolism and causes periodontitis in ruminants, occurs in the region and it is more prevalent at high altitudes. Traditional winter grounds at low elevations, sometimes far from high mountains, have been converted to livestock production, which has eliminated migratory behavior and keeps huemul in remote high-elevation refuges. Although this descriptive study contributes to huemul conservation, additional approaches are needed to investigate the etiology of this osteopathy and to close other gaps in knowledge on biology and ecology of huemul.

Fibrous dysplasia localized to spine: a diagnostic dilemma

Fibrous dysplasia of the spine is uncommon, especially in monostotic form. Isolated vertebral involvement in polyostotic form is very rare. We report a case of polyostotic fibrous dysplasia with lesions localized to dorso-lumbar spine in a 45-year-old rheumatoid arthritis patient. No associated appendicular lesions, cutaneous manifestations or endocrinopathies were seen. The extreme rarity of this type of lesion can pose a diagnostic dilemma, and biopsy is required for diagnosis. The association with rheumatoid arthritis in our case seems to be a chance occurrence.

Diagnosis and treatment for carcinoid tumors in the digestive tract

The authors analyzed the characteristics of carcinoid tumors according to their site in the digestive tract. Despite their low speed of growing and metastasis process, such neoplasias are malignant and must be submitted to surgical resection. Advanced cases with metastases are treated with somatostatin derivatives, lessening symptoms, causing occasional regression of lesions and presenting an extended survival. Appendicular and rectal lesions have a better prognosis maybe due to the early diagnosis performed.

Cortical metastatic lesions of the appendicular skeleton from tumors of known primary origin.

Metastatic disease represents the most common neoplastic process involving bone. Recently, a small subset of cortical based metastatic lesions has been identified. We attempted to delineate the incidence, origin, location, and possible significance of these lesions within an orthopaedic patient population. A chart and radiographic review of patients treated for metastatic disease to bone over a 17-year period was performed. Inclusion criteria for lesions were as follows: 1) an appendicular skeletal site, 2) histopathologic confirmation of origin, and 3) presence within a patient diagnosed with a single, known neoplastic process. The lesions were classified as either cortical or medullary based. Eighty-three lesions (70 patients) satisfied inclusion criteria. Most lesions were of pulmonary (26), breast (22), renal (16), or prostatic (8) tumor origin. Eighteen lesions (22%) from 15 patients were identified as cortical and represented initial presentation in 7 patients. These lesions were of pulmonary (11), renal (5), and breast (2) tumor origin. Cortical based metastases within the appendicular skeleton may occur more frequently than previously expected. While tumors of pulmonary and renal origin accounted for 42 of the 83 (51%) appendicular lesions, they were responsible for 16 of the 18 (89%) cortical metastases. This preponderance of pulmonary and renal metastases to the cortex is consistent with previously published reports. Our findings may be of value when diagnosing and treating patients whose initial presentation is a cortically based lesion.