Homogeneous Lesion Research Articles

Spontaneous Oculomotor and Abducens Nerve Palsy as Initial Presentation of Lymphoma of the Cavernous Sinus: Case Report

Primary lymphomas of the skull base are rare (1% of lymphomas in adults); they can originate from the cavernous sinus and the parasellar region. Diffuse large B-cell lymphoma is the most common histologic subtype. Currently, the origin of these lymphomas is controversial, and their clinical characteristics are not very specific. There are various treatments for these lesions with a variable response; therefore, the prognosis of these lesions is variable. Clinical case: We present the case of a 52-year-old man who spontaneously presented with diplopia. Physical examination revealed a limitation in adduction of the right eye, right palpebral ptosis, and limitation in the abduction of the left eye. Brain magnetic resonance imaging revealed a well-defined and homogeneous extra-axial lesion at the cavernous sinus level. The patient was biopsied and diagnosed with B-cell lymphoma; received chemotherapy and radiotherapy. In this article, we present a clinical case that considers the characteristics of the diagnosis and is the first B-cell lymphoma at the cavernous sinus level reported in Mexico. Conclusion: Skull base lymphomas have a broad clinical spectrum. Minimally invasive surgery for biopsy purposes is the gold standard for diagnosis, and the treatment with the best results is chemotherapy.

The role of endoscopic submucosal dissection in the management of gastric inflammatory fibroid polyps: a single-center experience.

gastric inflammatory fibroid polyps constitute only 0.1 % of all gastric polyps. They are usually amenable to resection by snare polypectomy. However, on rare occasions, these lesions may require resection by endoscopic submucosal dissection. This study aimed to evaluate the effectiveness and safety of endoscopic submucosal dissection in the management of gastric inflammatory fibroid polyps not amenable to resection with snare polypectomy. a retrospective observational study of all consecutive patients who underwent endoscopic submucosal dissection for gastric inflammatory fibroid polyps between January 2011 and December 2020 was performed. there were nine cases of gastric inflammatory fibroid polyps resected by endoscopic submucosal dissection. Most patients were female (7/9) with a mean age of 62.2 years. All gastric inflammatory fibroid polyps were described as solitary antral subepithelial lesions with a mean diameter of 16.7 mm, which appeared well-circumscribed and homogeneous lesions located at muscularis mucosa and submucosa without deeper invasion on endoscopic ultrasound. All lesions were successfully resected by en bloc and complete resection with free margins obtained in 8/9 specimens. Adverse events were reported in 2/9 cases including one intra-procedural bleeding successfully controlled with hemostatic clips and one aspiration pneumonia that evolved favorably. Mean follow-up duration was 33.7 months and no delayed complications or cases of recurrence were reported. endoscopic submucosal dissection appears safe and effective for the resection of gastric inflammatory fibroid polyps that present as large subepithelial lesions, if performed by experienced endoscopists after adequate characterization by endoscopic ultrasound, with high rates of technical success and low recurrence rates.

A Case of Choanal Polyp Originated from the Inferior Turbinate

The choanal polyp, originating from inferior turbinate, is known to be extremely rare. We report a case of a 65-year-old woman who was treated for choanal polyp originating from inferior turbinate. She had felt left nasal obstruction for two weeks. In the endoscopic examination, polypoid tissue covered with the mucopurulent discharge was observed filling the left inferior meatus. An ovoid homogenous enhancing lesion in the left posterior nasal cavity around the inferior turbinate was observed on CT and MRI. Endoscopic mass excision with partial inferior turbinectomy was performed under general anesthesia. The pedicle of the polyp was observed on the posterior side of the inferior turbinate. Complete resection including the mucosa around the pedicle of the choanal polyp was performed. The patient was followed up for seven months without any recurrence or complications.

Recurrent infantile inflammatory myofibroblastic tumor of mesentery––Case report and review of imaging findings

Inflammatory myofibroblastic tumors (IMT) are rare soft tissue tumors of intermediate malignant potential with tendency for local recurrence. Although they can occur at all age groups, occurrence in infants is extremely unusual and their imaging characteristics are not well described. A 3-month-old female infant presented with gradually progressive abdominal distention without any fever or weight loss. She had a large ill-defined homogenous hypodense lesion of size 8.4 × 11.4 × 11.3 cm (APxTraxSag) in the abdomen showing mild delayed post contrast enhancement. She underwent exploratory laparotomy with gross total excision of mesenteric mass, histopathology of which was suggestive of IMT. She had recurrence within 6 months of complete resection with a well-defined heterogeneously enhancing lesion of size 1.8 × 1.8 × 2.3cm (APxTraxSag) in right paravesical region abutting the bladder without invasion with a similar lesion of size 4.4 × 2.1 × 3 cm (APxTraxSag) in left subdiaphragmatic region abutting superior surface of spleen (no invasion). Since, surgery in our patient would have entailed splenectomy and partial cystectomy, systemic therapy with ceritinib (anaplastic lymphoma kinase [ALK] inhibitor) was planned for her with which she had a near complete response after 2 months. A high index of suspicion is required to differentiate IMT from other common causes of mesenteric masses in children and role of radiologist is quintessential in this regard. Local recurrence with abutment but without invasion of surrounding structures points to the intermediate malignant pathology of IMT and may provide a clue to diagnosis. Systemic therapy is effective in patients who are ALK positive and destructive surgery should be avoided.

Fundus imaging features of purified protein derivative and T-spot positive tubercular serpiginous-like choroiditis

Objective: To summarize the clinical and fundus imaging features of purified protein derivative and T-spot positive tubercular serpiginous-like choroiditis (PTP-SLC) patients. Methods: This retrospective study consecutively enrolled 13 PTP-SLC patients (21 eyes) in Beijing Tongren Hospital from November 2015 to November 2017. There were 8 males and 5 females with an average age of (45.2±12.1) years. Medical history and results of systemic and ophthalmological examinations, such us fundus autofluorescence photography, optical coherence tomography (OCT), fluorescein fundus angiography (FFA) and indocyanine green angiography, were evaluated. Results: Eight patients had binocular disease with an average interval time of (8.4±7.9) years. The average visual acuity of all patients was 0.3, and 4 patients had a clear history of exposure to tuberculosis. The active lesions in the PTP-SLC patients were homogeneous and creamish-yellow with unclear boundaries. Fundus autofluorescence showed an ill-defined, diffuse hyperautofluorescent zone. OCT showed punctate hyperreflexes between the choroidal stroma, destruction of the outer retinal structure with intraretinal edema and discrete vitreal hyper-reflective spots. FFA showed hypofluorescence in the active lesion at early stage and diffuse hyperfluorescence with leakage. Indocyanine green angiography showed persistent hypofluorescence. Conclusions: PTP-SLC fundus lesions are mainly manifested as homogeneous creamish-yellow lesions with unclear boundaries and high in autofluorescence. The involvement of the choroid and the outer layer of the retina can be observed on OCT. FFA can find more retinal vascular inflammatory changes. It is difficult to distinguish PTP-SLC from serpiginous choroiditis simply based on clinical and epidemiological characteristics. The pathogenic examination of tuberculosis is still the key to differential diagnosis (Chin J Ophthalmol, 2020, 56: 914-919).

IgG4-related lymphadenopathy \u2013 a difficult diagnosis

BackgroundThe IgG4-related disease (IgG4-RD) is a systemic immune-mediated non-neoplastic disease associated with IgG4 positive plasma cells and fibrosis that often presents as a mass lesion. Although the disease could affect virtually any anatomical site, there are strong predilections for certain organs. IgG4-related lymphadenopathy can exhibit a broad morphologic spectrum. We describe a patient with IgG4-related lymphadenopathy with overlapping histological features that proved to be a diagnostic red herring.Case presentationA 58-year-old gentleman with multiple co-morbidities presented with obstructive jaundice, elevated transaminases, and bilateral inguinal and left axillary lymphadenopathy. Imaging of the abdomen and pelvis showed circumferential soft tissue thickening resulting in luminal narrowing of common and proximal bile duct with upstream intrahepatic biliary radicle dilatation, multiple enlarged lymph nodes, and homogenous soft tissue lesions in the tail of the pancreas and bilateral renal cortical parenchyma with perinephric soft tissue extension. Left inguinal, and axillary lymph node excision biopsies were suggestive of IgG4-RD. Serum IgG4 levels performed subsequently, were markedly elevated. The patient was treated with prednisone which led to resolutions of his symptoms, reduction in the size of the lesions, and reversal of abnormal laboratory parameters.ConclusionThe diagnosis of IgG4-RD in lymph node excision biopsy is a difficult call to make and needs a multidisciplinary team. An early diagnosis renders timely intervention and prevents the progression of the disease and its complications.

Giant Parotid Stone Causing Mucosal Ulceration and Pus Discharge: Report of a Rare Case

Introduction: Sialolith is the most common condition of the salivary gland disorders after mumps, which usually occurs in the submandibular gland. A rare case of giant parotid sialolith is described. Case Report: A 58-years-old man with a complaint of swelling in the buccal area referred to the Department of Oral Medicine of the Dental School of Semnan University. A mild swelling was observed in the right cheek area in front of Ramus during the extraoral examination. Iintraoral evaluation revealed a 2.5 × 2 cm swelling with same color of the mucous membrane, adjacent to the maxillary first molar at the Parotid Papilla area, and with a stony-hard consistency. In the radiographic imaging, an estimated 18×6 mm homogenous opaque lesion was recognized; hence, the sialolith diagnosis was suggested. Surgical removal with electrocautery was done and no complaints were reported one month after the surgery. Conclusion: Since giant sialolith can lead to complications which may affect patients’ quality of life, surgical treatment of such lesion is strongly recommended.

Endoscopic Recognition and Management Strategies for Malignant Colorectal Polyps: Recommendations of the US Multi-Society Task Force on Colorectal Cancer.

Endoscopic Recognition and Management Strategies for Malignant Colorectal Polyps: Recommendations of the US Multi-Society Task Force on Colorectal Cancer.

A Rare Inflammatory Myofibroblastic Tumor of Pancreas in a Child With Cholestasis Presentation

Inflammatory myofibroblastic tumors (IMTs) are rare with unknown etiology. As pancreas involvement is rare in IMTs, here, we report a case of a girl with IMT, referred to our hospital. A 4-year-old girl presented with chief complaints of generalized itching and jaundice. Abdominopelvic computed tomography (CT) scans with contrast showed a homogeneous isodense mass lesion in the head of the pancreas with a compressive effect on the distal part of the common bile duct (CBD). Dilatation of intrahepatic bile ducts and CBD (8 mm) was observed. Magnetic resonance cholangiopancreatography (MRCP) examination showed a dilated gallbladder without stones and intrahepatic/extrahepatic bile ducts. The CBD was dilated, and a mass was found in the head of the pancreas. Immune-histochemical studies revealed spindle myofibroblastic tissues with lymphoplasmacytic and eosinophil infiltration. All of them were compatible with pancreatic IMTs. The surgery improved the symptoms. The IMTs of the pancreas can have symptoms like pancreatic cancer. The careful evaluation by imaging and pathology is recommended.

Three-dimensional regions-of-interest-based intra-operative four-dimensional soft tissue perfusion imaging using a standard x-ray system with no gantry rotation: A simulation study for a proof of concept.

Many interventional procedures aim at changing soft tissue perfusion or blood flow. One problem at present is that soft tissue perfusion and its changes cannot be assessed in an interventional suite because cone-beam computed tomography is too slow (it takes 4-10s per volume scan). In order to address the problem, we propose a novel method called IPEN for Intra-operative four-dimensional soft tissue PErfusion using a standard x-ray system with No gantry rotation. IPEN uses two input datasets: (a) the contours and locations of three-dimensional regions-of-interest (ROIs) such as arteries and sub-sections of cancerous lesions, and (b) a series of x-ray projection data obtained from an intra-arterial contrast injection to contrast enhancement to wash-out. IPEN then estimates a time-enhancement curve (TEC) for each ROI directly from projections without reconstructing cross-sectional images by maximizing the agreement between synthesized and measured projections with a temporal roughness penalty. When path lengths through ROIs are known for each x-ray beam, the ROI-specific enhancement can be accurately estimated from projections. Computer simulations are performed to assess the performance of the IPEN algorithm. Intra-arterial contrast-enhanced liver scans over 25s were simulated using XCAT phantom version 2.0 with heterogeneous tissue textures and cancerous lesions. The following four sub-studies were performed: (a) The accuracy of the estimated TECs with overlapped lesions was evaluated at various noise (dose) levels with either homogeneous or heterogeneous lesion enhancement patterns; (b) the accuracy of IPEN with inaccurate ROI contours was assessed; (c) we investigated how overlapping ROIs and noise in projections affected the accuracy of the IPEN algorithm; and (d) the accuracy of the perfusion indices was assessed. The TECs estimated by IPEN were sufficiently accurate at a reference dose level with the root-mean-square deviation (RMSD) of 0.0027±0.0001cm-1 or 13±1 Hounsfield unit (mean±standard deviation) for the homogeneous lesion enhancement and 0.0032±0.0005cm-1 for the heterogeneous enhancement (N=20 each). The accuracy was degraded with decreasing doses: The RMSD with homogeneous enhancement was 0.0220±0.0003cm-1 for 20% of the reference dose level. Performing 3×3 pixel averaging on projection data improved the RMSDs to 0.0051±0.0002cm-1 for 20% dose. When the ROI contours were inaccurate, smaller ROI contours resulted in positive biases in TECs, whereas larger ROI contours produced negative biases. The bias remained small, within±0.0070cm-1 , when the Sorenson-Dice coefficients (SDCs) were larger than 0.81. The RMSD of the TEC estimation was strongly associated with the condition of the problem, which can be empirically quantified using the condition number of a matrix that maps a vector of ROI enhancement values to projection data and a weighted variance of projection data: a linear correlation coefficient (R) was 0.794 (P<0.001). The perfusion index values computed from the estimated TECs agreed well with the true values (R≥0.985, P<0.0001). The IPEN algorithm can estimate ROI-specific TECs with high accuracy especially when 3×3 pixel averaging is applied, even when lesion enhancement is heterogeneous, or ROI contours are inaccurate but the SDC is at least 0.81.

Neuroendocrine carcinoma of uterine cervix findings shown by MRI for staging and survival analysis - Japan multicenter study.

Objectives: To investigate neuroendocrine carcinoma (NEC) of the uterine cervix cases for MRI features and staging, as well as pathological correlations and survival.Results: FIGO was I in 42, II in 14, III in 1, and IV in 5 patients. T2-weighted MRI showed homogeneous slightly high signal intensity and obvious restricted diffusion (ADC map, low intensity; DWI, high intensity) throughout the tumor in most cases, and mild enhancement in two-thirds. In 50 patients who underwent a radical hysterectomy and lymphadenectomy without neoadjuvant chemotherapy (NAC), intrapelvic T staging by MRI overall accuracy was 88.0% with reference to pathology staging, while patient-based sensitivity, specificity, and accuracy for metastatic pelvic lymph node detection was 38.5%, 100%, and 83.3%, respectively. During a mean follow-up period of 45.6 months (range 4.3–151.0 months), 28 patients (45.2%) experienced recurrence and 24 (38.7%) died. Three-year progression-free and overall survival rates for FIGO I, II, III, and IV were 64.3% and 80.9%, 50% and 64.3%, 0% and 0%, and 0% and 0%, respectively.Materials and Methods: Sixty-two patients with histologically surgery-proven uterine cervical NEC were enrolled. Twelve received NAC. Clinical data, pathological findings, and pretreatment pelvic MRI findings were retrospectively reviewed. Thirty-two tumors were pure NEC and 30 mixed with other histotypes. The NECs were small cell type (41), large cell type (18), or a mixture of both (3).Conclusions: Homogeneous lesion texture with obvious restricted diffusion throughout the tumor are features suggestive of cervical NEC. Our findings show that MRI is reliable for T staging of cervical NEC.

Papillary Lesions of the Breast: A Review

Papillary breast lesions are rare breast tumors that comprise a broad spectrum of diseases. Pathologically they present as mass-like projections attached to the wall of the ducts, supported by fibrovascular stalks lined by epithelial cells. On mammogram they appear as masses that can be associated with microcalcifications. Ultrasound is the most used imaging modality. On ultrasound papillary lesions appear as homogeneous solid lesions or complex intracystic lesions. A nonparallel orientation, an echogenic halo or posterior acoustic enhancement associated with microcalcifications are highly suggestive of malignancy. MRI has proven to be useful to establish the extent of the lesion. Core needle biopsy is the gold standard for diagnosis. Surgical excision is usually recommended, although treatment for papillomas without atypia is still controversial.

Appearance of recurrent dermatofibrosarcoma protuberans in postoperative MRI follow-up

Purpose: To analyze the appearance of recurrent dermatofibrosarcoma protuberans (DFSP) in postoperative MRI follow-up and to assess the occurrence of postoperative soft tissue changes detected in MRI.Methods: A total of 464 MRI follow-up scans of 32 patients with histologically proven diagnosis of DFSP were analyzed. MR imaging was performed using a 1.5T MRI system. Recurrent DFSP was examined for signal intensity, contrast behavior, appearance, and extent in MRI.Results: The mean age of the patients was 44,5±17,1 years. Recurrences of DFSP occurred 26±23.3 months after primary tumor resection in the mean (Min.: 9, Max.: 60). In 25% of the patients (n = 8), recurrences of DFSP were detected. Recurrent DFSP most often showed a nodular and homogeneous configuration with well-defined borders and marked contrast enhancement, and a hyperintense signal in PD-weighted and turbo inversion recovery magnitude sequences. All recurrences were well detected in the follow-up MRIs regardless of the performed plastic surgery procedure. Lateral and depth margins had no significant impact on the local recurrence rate. In all, 88% of the patients developed subcutaneous tissue edema (p < 0.01), followed by muscle edema (34%, p = 0.02), and postoperative seroma (22%).Conclusion: Recurrent DFSP mainly appear uniform and clearly delimitable on MRI as nodular, homogeneous, and well-defined lesions with marked contrast enhancement. Therefore, MRI is a valuable tool for postsurgical follow-up. Nearly all patients develop subcutaneous edema after the resection of DFSP.

Diagnostic imaging of parotid gland oncocytoma: a pictorial review with emphasis on ultrasound assessment

Parotid gland oncocytoma (PGO) is a rare benign epithelial tumor that usually occurs in the elderly population. The most common clinical presentation is a painless, slow-growing, non-tender, lobulated, and mobile mass. Histologically, it is composed of monotonous sheets of epithelial cells (oncocytes) with a central scar. The cross-sectional appearance is not specific, and it overlaps with other parotid lesions. On ultrasound (US), oncocytoma appears as an ovoid, well-defined, homogeneous, and hypoechoic lesion. Cystic and hemorrhagic areas as well as intralesional fat may be observed. Doppler analysis shows intratumoral vessels, sometimes with a spoke-wheel pattern. The peak systolic flow is high (up to 100cm/sec). Furthermore, oncocytoma is avid of FDG on a PET scan, as well as a malignant tumor. Thus, a combined clinical, imaging, and pathologic assessment is essential to establish the most accurate diagnosis and plan the best treatment. US, combined with Doppler techniques, can play an important role in suggesting the diagnosis and confirming it through percutaneous sampling. The purpose of this review is to show the imaging findings in PGO, with special emphasis on the US appearance.

Cervical cystic lymphangioma

Our work is about a 34-year-old woman with no particular history who was admitted for a cervical mass which showed a substantial increase in size in the last 8 months. Physical examination revealed a fluctuant and painless mass in the right posterior triangle which was tender on palpation. CT scan of the neck showed a multi-loculated homogeneous cystic lesion located primarily in the right posterior cervical triangle, and extending to the right deep cervical spaces, underneath an elevated sternocleidomastoid muscle. The right jugular vein, while relatively compressed, was still patent. There was no contrast enhancement after intravenous injection. The patient underwent complete surgical excision by transverse neck incision and the diagnosis of lymphangioma was confirmed on histological examination.

Experience with Esophageal Granular Cell Tumors: Clinical and Endoscopic Analysis of 22 Cases.

Esophageal granular cell tumors (GCTs) are rare tumors. Differences in reports on the clinical features of GCTs in the esophagus and some controversies about the diagnostic strategy for esophageal GCTs exist. We aimed to investigate the clinical features and diagnosis of esophageal GCTs. Additionally, we sought to determine the prevalence of gastroesophageal reflux disease and reflux esophagitis in patients with esophageal GCTs. We retrospectively studied the clinical features, endoscopic features, and management of 22 patients with esophageal GCTs. Esophageal GCTs were more common in men than in women with a ratio of 1.2:1 and were predominantly found in the distal esophagus. Ten patients with esophageal GCTs had regurgitation and/or heartburn symptoms, and eight patients were confirmed to have reflux esophagitis by endoscopy. All esophageal GCTs were protuberant lesions covered by normal esophageal epithelium. The endoscopic morphology of esophageal GCTs was diverse. On endoscopic ultrasonography, these tumors appeared as homogeneous or inhomogeneous hypoechoic lesions with clear borders originating from the submucosal or mucosal layer. Eleven patients underwent endoscopic forceps biopsy at the first endoscopy, and only six patients were correctly diagnosed by pathology. Nevertheless, the 18 lesions treated with endoscopic resection were all correctly diagnosed without complications, and no patients developed recurrence during the follow-up period. The occurrence of esophageal GCTs may be related to esophageal inflammation. As a method for obtaining an accurate pathological diagnosis and for treatment, endoscopic resection should be offered as the primary option for patients with esophageal GCTs.

Identification of chronic subdural hematoma types most responsive to Goreisan, Kampo medicine: A retrospective study

Chronic subdural hematoma (CSDH) has a reported postoperative recurrence rate of 3–20% and the optimal therapeutic strategy remains controversial. Recently, in Japan, Goreisan (Kampo medicine) was used for preventing postoperative CSDH recurrence. Therefore, this study aimed to explore if Goreisan is effective against specific CSDH types by evaluating its effects on postoperative CSDH recurrence and reoperation rates based on its natural history and internal structure on CT images. This retrospective, single-center, cohort study was conducted at the Tokyo Metropolitan Hiroo Hospital. After applying the inclusion/exclusion criteria, data from 107 patients (70 men and 37 women; mean age, 77.1 ± 10.9 years), admitted for CSDH from January 2013 to December 2018, were included in the Goreisan group, whereas those of 122 patients (84 men and 38 women; mean age, 73.9 ± 13.3 years), admitted for CSDH from January 2007 to December 2012, were included in the control group. This corresponded to 114 lesions, with 14 reoperation lesions, in the Goreisan group and 108 lesions, with 16 reoperation lesions, in the control group. Lesions were categorized as homogeneous, laminar, separated, or trabecular type, and patients with homogeneous type lesions in the Goreisan group were approximately 50% less likely to undergo reoperation compared with those in the control group (7.3% versus 14%; odds ratio = 0.51; 95% confidence interval = 0.12–2.11). Thus, the homogeneous type CSDH was the most responsive to Goreisan, whereas the separated type was the least responsive. Therefore, selecting treatment strategies for preventing CSDH recurrence on CSDH type may contribute toward reducing reoperation rates.

Where in the World Did You Get That Rash?

1. Panteha Eshtiaghi, HBSc* 2. Miriam Weinstein, MD, FRCPC† 1. *Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada 2. †Hospital for Sick Children, Toronto, Ontario, Canada * Abbreviations: ACD: : allergic contact dermatitis CD: : cercarial dermatitis CL: : cutaneous leishmaniasis CLM: : cutaneous larva migrans DF: : dengue fever HFMD: : hand, foot, and mouth disease HSV: : herpes simplex virus KD: : Kawasaki disease PCR: : polymerase chain reaction PR: : pityriasis rosea RT-PCR: : reverse transcriptase polymerase chain reaction The challenge to diagnose cutaneous eruptions and lesions in patients who have spent time in foreign countries is increasingly common. With the advent of increased global travel, foreign adoptions, immigration, and refugee seekers, rashes that were once relegated to the realm of the exotic and likely to show up in a tropical diseases clinic may now present to a general pediatrician. Furthermore, the pediatric traveler is at increased risk for dermatoses. (1) It behooves the practitioner to be aware of these skin findings, to be able to recognize them and distinguish them from other skin conditions. After completing this article, readers should be able to: 1. Identify and classify rashes by main morphologic patterns. 2. Develop a broad differential diagnosis and diagnostic approach for a rash in a returned pediatric traveler based on initial morphology, history, epidemiology, and other clinical features. 3. Consider both infectious and noninfectious causes of skin disorders presenting in a patient with a travel history. 4. Outline the basic investigations and principles of management for travel-acquired and non–travel-acquired dermatologic illnesses. 5. Discuss …

Dose Gradient Index for Stereotactic Radiosurgery/Radiation Therapy

Steep dose falloff outside of tumors is a hallmark of stereotactic radiosurgery (SRS) and radiation therapy (SRT). Dose gradient index (DGI) quantifies the dose drop off. Tables of DGIs versus target volumes have been published for body sites, but none is available for brain. This study recommends guidelines for DGIs for brain SRS/SRT treatments based on clinical CyberKnife (CK) cases. Four hundred ninety-five plans for patients with central nervous system tumors treated with CK at our institution between March 2015 and May 2018 were analyzed. The CK treatment planning system MultiPlan was used for planning. SRS/SRT plans were stratified into 6 groups by tumor size (Group I [0-1 cm3], II [1.0-3.0 cm3], III [3.0-5.0 cm3], IV [5.0-10.0 cm3], V [10.0-15.0 cm3], and VI [15.0-40.0 cm3]). Ideal and minimally acceptable DGIs were determined for each size group. To evaluate the effect of target shape on DGI criteria, the plans were divided into 4 target shape groups: (1) homogeneous shape (circular), (2) adjacent to radiosensitive organs at risk (adjacent), (3) irregularly shaped (irregular), and (4) multiple target plans (multilesion). The mean for each target size group was defined as the ideal DGI. Minimally acceptable DGI criteria are specified to reject the lowest 10% of cases. The minimal acceptable DGIs were 83 (Group I), 72 (II), 65 (III), 58 (IV), 52 (V), and 35 (VI). The ideal DGI is designated to evaluate SRS/SRT plans for homogeneous circular lesions, whereas minimal DGI is chosen to assess the plans for irregular, adjacent to organs at risk, and multilesions. SRS/SRT plans with higher DGI values are correlated with lower irradiated normal tissue volumes. This study provides a table of DGIs for brain SRS/SRT treatments as a tool for assessing the quality of intracranial SRS/SRT plans. DGI guidelines support SRS/SRT planning that results in lower risk of radionecrosis.

Primary retroperitoneum mucinous cystadenoma

Primary retroperitoneal mucinous cystadenomas (PRMCs) are observed more frequently in women with no specific symptoms. A 35 Years old female patient presented with Intermittent abdominal pain in her left flank associated with fullness in abdomen. CECT confirmed a well-defined smoothly marginated homogenous non-enhancing unilocular cystic lesion in retroperitoneum in left lumbar region, separated from the pancreas, left kidney and ovary. On Laprotomy, the retroperitoneal tumor was completely removed, without spillage of its contents.