[Lipid cell variant urothelial carcinoma of the renal pelvis. A case report and literature review]. / Carcinoma urotelial lipoideo de pelvis renal. Aportación de un nuevo caso y revisión de la literatura de esta variante de carcinoma urotelial.

There are many variants of urothelial carcinoma. One of the most infrequent is formed by cells with a lipid content and an adipose tissue appearance. Only 43 cases have been reported in the bladder, 2 in the renal pelvis and 1 case in the ureter. We present a third case in the renal pelvis; the patient is alive and free of disease 103 months post diagnosis.

Lipomatous hypertrophy of the interventricular septum.

BACKGROUND AND AIMS: Lipomatous hypertrophy of the interatrial septum is an uncommon type of cardiac adipose tumor. It is extremely rare for these lesions to be located in the interventricular septum. METHODS: We report this case of incidentally diagnosed lipomatous hypertrophy of the interventricular septum with right ventricular outflow obstruction which caused minimal symptoms and Wolff-Parkinson-White pattern on EKG. CONCLUSION: We also discuss the diagnosis and management of this condition.

A Diagnostic Dilemma of a Subcutaneous Hibernoma: Case Report.

BACKGROUND Subcutaneous lipomatous lesions are commonly encountered in clinical practice. Hibernoma is a rare subtype of the benign lipomatous tumor, representing 1% of all types. It poses a challenge due to the difficulty of differentiating it from atypical lipomatous lesions and liposarcomas, which may lead to possible inappropriate diagnosis and management. CASE REPORT We report a case of a 33-year-old male who presented with a right upper thigh swelling noticed some time prior to presentation that had started increasing in size prior to his presentation. The magnetic resonance imaging (MRI) was unable to rule out atypical lipomatous tumor and liposarcoma. An ultrasound-guided biopsy gave a diagnosis of hibernoma. The patient underwent a wide local excision, which confirmed the diagnosis of hibernoma. At the 3-year follow-up, there was no evidence of local recurrence. CONCLUSIONS Hibernoma has been reported in the literature to be discovered incidentally by radiological imaging done for other causes. However, hibernomas raise a diagnostic challenge because in most imaging modalities they are indistinguishable from other malignant tumors. A wide local excision with negative margins is key to resolving the diagnostic dilemma that a hibernoma presents, as it will provide a definitive diagnosis differentiating it from other lipomatous lesions and prevent any future recurrence. Caution is advised when dealing with lipomatous lesions, as they often overlap with malignancy. Furthermore, an MRI should be done for any subcutaneous lesion that is larger than 5 cm or shows recent growth. A biopsy can resolve the diagnostic dilemma with caution to the hypervascularity of such tumors.

Surgical management of truncal and extremities atypical lipomatous tumors/well-differentiated liposarcoma: A systematic review of the literature.

INTRODUCTION: Atypical lipomatous tumors or well-differentiated liposarcomas (ALT/WDLS) are low-grade soft tissue tumors that are commonly located on the trunk and extremities. There is no consensus on the best surgical approach for ALT/WDLS. METHODS: A systematic literature review of PubMed, Medline, Embase, Scopus, and google scholar was performed. All published studies on trunk or extremities ALT/WDLS with reported outcome data were considered and independently screened for inclusion by at least two of the authors. RESULTS: A total of eighteen studies comprising 793 patients with ALT/WDLS were included. 580 patients underwent marginal excision, with local recurrence observed in 69 (11.9%). 213 patients underwent wide excision with local recurrence in 7(3.3%). Recurrent tumors were successfully re-resected with marginal or wide excision. Dedifferentiation was confirmed in 9 patients (1.1%), and a distant pulmonary metastasis in 1 patient (0.1%). DISCUSSION: Marginal excision of truncal or extremities ALT/WDLS results in a slightly higher local recurrence rate. However, recurrences are almost always amenable to re-resection. The findings support the use of marginal excision for truncal or extremities ALT/WDLS.

Extranodal extension of lymph node metastasis influences recurrence in prostate cancer: a systematic review and meta-analysis.

The extranodal extension (ENE) of nodal metastasis involves the extension of neoplastic cells through the lymph node capsule into the perinodal adipose tissue. This morphological feature has recently been indicated as an important prognostic factor in various cancer types, but its role in prostate cancer is still unclear. We aimed to clarify it, performing the first meta-analysis on this issue, comparing prognostic parameters in surgically treated, node-positive prostate cancer patients with (ENE+) vs. without (ENE-) ENE. Data were summarized using risk ratios (RRs) for number of deaths/recurrences and hazard ratios (HRs), with 95% confidence intervals (CI), for the time-dependent risk related to ENE positivity. Six studies followed-up 1,113 patients with N1 prostate cancer (658 ENE+ vs. 455 ENE-) for a median of 83 months. The presence of ENE was associated with a significantly higher risk of biochemical recurrence (RR = 1.15; 95%CI: 1.03-1.28; I2 = 0%; HR = 1.40, 95%CI: 1.12-1.74; I2 = 0%) and "global" (biochemical recurrence and distant metastasis) recurrence (RR = 1.15; 95%CI: 1.04-1.28; I2 = 0%; HR = 1.41, 95%CI: 1.14-1.74; I2 = 0%). ENE emerged as a potential prognostic moderator, earmarking a subgroup of patients at higher risk of recurrence. It may be considered for the prognostic stratification of metastatic patients. New possible therapeutic approaches may explore more in depth this prognostic parameter.

Intraoperative optical coherence tomography for soft tissue sarcoma differentiation and margin identification.

BACKGROUND AND OBJECTIVE: Sarcomas are rare but highly aggressive tumors, and local recurrence after surgical excision can occur in up to 50% cases. Therefore, there is a strong clinical need for accurate tissue differentiation and margin assessment to reduce incomplete resection and local recurrence. The purpose of this study was to investigate the use of optical coherence tomography (OCT) and a novel image texture-based processing algorithm to differentiate sarcoma from muscle and adipose tissue. STUDY DESIGN AND METHODS: In this study, tumor margin delineation in 19 feline and canine veterinary patients was achieved with intraoperative OCT to help validate tumor resection. While differentiation of lower-scattering adipose tissue from higher-scattering muscle and tumor tissue was relatively straightforward, it was more challenging to distinguish between dense highly scattering muscle and tumor tissue types based on scattering intensity and microstructural features alone. To improve tissue-type differentiation in a more objective and automated manner, three descriptive statistical metrics, namely the coefficient of variation (CV), standard deviation (STD), and Range, were implemented in a custom algorithm applied to the OCT images. RESULTS: Over 22,800 OCT images were collected intraoperatively from over 38 sites on 19 ex vivo tissue specimens removed during sarcoma surgeries. Following the generation of an initial set of OCT images correlated with standard hematoxylin and eosin-stained histopathology, over 760 images were subsequently used for automated analysis. Using texture-based image processing metrics, OCT images of sarcoma, muscle, and adipose tissue were all found to be statistically different from one another (P ≤ 0.001). CONCLUSION: These results demonstrate the potential of using intraoperative OCT, along with an automated tissue differentiation algorithm, as a guidance tool for soft tissue sarcoma margin delineation in the operating room. Lasers Surg. Med. 49:240-248, 2017. © 2017 Wiley Periodicals, Inc.

Juxtaarticular Myxoma in a Pigtail Macaque (Macaca nemestrina).

A 10-y-old pigtail macaque presented with a subcutaneous, soft-tissue mass overlying the right stifle joint. Here we describe the clinical case and histopathologic and immunohistochemical analysis of this lesion. This case represents the first published report of juxtaarticular myxoma in a pigtail macaque.

Lipomatous tumours of the head and neck: a spectrum of biological behaviour.

Lipomatous tumours are rare in the head and neck region. Their biological behaviour varies greatly, from absolutely benign to histologically benign but locally infiltrative and, finally, invasive with metastatic potential. Each lipomatous tumour has to be treated accordingly. It is of paramount importance before eventual surgery is planned to perform adequate imaging, diagnostic biopsy and careful assessment. Only in small (<5 cm), superficial soft tissue tumours or when magnetic resonance imaging has demonstrated specific features of lipoma, may diagnostic biopsy be omitted. In these cases, expectant management or simple excision is appropriate. Adequate preoperative diagnosis is important to assure adequate tumour control as well as optimal functional and cosmetic outcome. The major problem in the treatment of lipomatous tumours of the head and neck region is the presence of nearby delicate structures. Especially, wide surgical excision of liposarcomas may be hindered by anatomic constraints and may result in impaired functional and cosmetic outcome. Neoadjuvant radiotherapy and specific systemic chemotherapy may be helpful in the treatment of liposarcoma, especially when unresectable or when primary surgery is expected to result in poor oncological, functional or cosmetic outcome. Greater emphasis placed on the underlying biology of individual sarcoma subtypes, development and evaluation of novel therapies and greater specificity in the selection of chemotherapy agents based on activity in individual histological subtypes are expected to lead to improved efficacy of systemic treatment.

[A case of late perirenal fat recurrence after partial nephrectomy for T1A renal cell carcinoma].

An 84-year-old man had undergone laparoscopic partial nephrectomy for right renal cell carcinoma (RCC), cT1aN0M0 in 2003. The histopathological diagnosis was clear cell carcinoma, grade 1, v (-), surgical margin negative, pT1a. Nine years and 10 months postoperatively, computed tomography scans demonstrated tumors on right renal fossa. As we could not detect other metastatic lesions, we diagnosed him with local recurrence of RCC and planned the surgery with curative intent. He underwent laparoscopic resection of retroperitoneal tumors. The histopathological diagnosis was clear cell carcinoma, grade 2 ＞ 3, v (-), surgical margin negative, and confirmed recurrence of RCC. In retrospective review of 176 cases of pT1a renal cell carcinoma with partial nephrectomy in our institute, 3 patients (1.7%) developed local recurrence and 2 patients (1.1%) developed late local recurrence.

The General Surgeon's quandary: atypical lipomatous tumor vs lipoma, who needs a surgical oncologist?

BACKGROUND: Differentiating large lipomas from atypical lipomatous tumors (ALT) is challenging, and preoperative management guidelines are not well defined. The diagnostic ambiguity leads many surgeons to refer all patients with large lipomatous masses to an oncologic specialist, perhaps unnecessarily. STUDY DESIGN: In this retrospective cohort study of patients with nonretroperitoneal lipomatous tumors, preoperative characteristics discernible without invasive diagnostic procedures were evaluated for diagnostic predictive value. RESULTS: We identified 319 patients (256 with lipomas, 63 with ALTs) treated between 1994 and 2012. Patients with ALTs were older (60.5 vs 53.5 years, p < 0.0001), had larger tumors (16.0 vs 8.3 cm, p < 0.0001), had tumors more often located on an extremity (88.9% vs 60.5% torso, p < 0.0001), and more frequently had a history of previous operations at the same site, exclusive of excision leading to diagnosis and referral (20.6% vs 5.9%, p = 0.001). Local recurrence was observed in 2 patients with lipomas (0.8%) vs 14 with ALTs (22.6%, p < 0.0001). No patients with ALTs developed distant metastases or disease-specific mortality, with a median follow-up of 27.4 months (range 0 to 164.6 months). On multivariate analysis, age ≥ 55 years, tumor size ≥ 10 cm, extremity location, and history of previous resections were predictors for diagnosis of ALT (p < 0.05). CONCLUSIONS: Characteristics of lipomatous masses associated with a diagnosis of ALT include patient age ≥ 55 years, tumor size ≥ 10 cm, previous resection, and extremity location (vs torso). These easily identifiable traits may guide surgical management or referral to a specialist.

Palmar well differentiated spindle cell liposarcoma: presentation of a rare tumor at a rare site.

The most common soft tissue sarcomas of hand are epitheloid sarcomas, synovial sarcomas and malignant fibrous histiocytomas which are high grade, aggressive tumors. Liposarcomas of the hand are extremely rare and to the best of our knowledge less than 20 cases have been reported so far in the literature. Well differentiated spindle cell liposarcoma is an extremely rare subtype of well differentiated liposarcoma/atypical lipomatous tumor which is different from the other subtypes clinicopathologically, genetically and prognostically. Palmar localization of this rare variant of liposarcoma at this site makes ours only the second case reported in the world literature so far. This recently described entity is low grade lesion and the hand surgeons need to adopt a less aggressive approach in the treatment of this subtype.

Intracoelomic anaplastic sarcoma in an intersex Madagascar tree boa (Sanzinia madagascariensis).

An adult Madagascar tree boa (Sanzinia madagascariensis) underwent coeliotomy for investigation of a coelomic mass. At surgery, a large mass originating from the peri-pancreatic adipose tissue and involving the gall bladder was removed. The snake did not recover from general anesthesia. A complete postmortem was performed, and samples were submitted to the University of Glasgow for histopathology. On histological examination, the mass was composed of adipose tissue infiltrated with a poorly demarcated spindle cell neoplasm. The neoplastic cells were highly pleomorphic with abundant cytoplasm and frequent clear cytoplasmic vacuoles, suggestive of adipocyte origin. Immunohistochemical characterization of the mass was inconclusive. Metastatic neoplastic cells were present within vessels in the liver, lungs, and brain. As an incidental finding, the gonads contained both maturing ovarian follicles and seminiferous tubules with intact germinal epithelium and evidence of spermatogenesis, along with other features of male and female gonad anatomy. The current report describes a rare neoplasm in snakes within an intersex Madagascar tree boa.

Large para-articular osteochondroma of the knee joint: a case report.

A unique case of large intra-articular osteochondroma of the knee of a 15-year duration is presented along with a review of the literature. The tumor may have remained asymptomatic for such a long period because of its slow growth and stretch elongation of the quadriceps mechanism.

Large parasitic myomas in abdominal subcutaneous adipose tissue along a previous myomectomy scar.

The incidence of iatrogenic parasitic uterine myomas associated with the use of a laparoscopic morcellator has been increasing over the past decade. Recently, we encountered a very rare case with a large parasitic myoma measuring 12 cm in diameter in the abdominal subcutaneous adipose tissue along an abdominal longitudinal surgical scar. The patient had twice undergone abdominal myomectomy for multiple fundal myomas. This is the first report describing a case with as large a parasitic myoma presenting in the suprafascial adipose tissue under the surgical scar after laparotomy. In such a case demonstrating a solid tumor of unknown cause after a gynecologic surgical procedure, a parasitic myoma must be included in the differential diagnosis.

Surgical technique of the transoral approach to remove a lipoma of the buccal fat pad.

BACKGROUND: In 1727, Heister (Compendium anatomicum. Altdorf, Guill, Koleshii: editio tertia 1727: 134, table VIII and figs. 36-37) described the buccal fat pad (BFP) as an independent anatomic structure of the face; in 1801, Bichat (Anatomie generale appliquee a la physiologie et a la medecine. Paris, France: Brosson, Gabon et Cie Libraires, 1801:60) reported his fatty histologic finding. According to the literature, several pathologic tumorous conditions can arise from BFP, such as lipoma, lipoblastomatosis, liposarcoma, hemangioma, arteriovenous malformation, and nodular fasciitis; all of which are rare. After a revision of the English literature performed through PubMed between 1948 and 2008, we found 10 cases of lipomas arising from the BFP (7 cases are simple subtype, 2 are spindle cell lipoma, and 1 is fibrolipoma). The aims of this study were to introduce our clinical report of this rare pathologic entity, describe the surgical technique of the transoral approach, and discuss the potential pitfalls regarding the preoperative diagnosis and the close interrelation among the BFP, the facial buccal branches (FBBs), and the parotid duct (PD). CLINICAL REPORT: A 43-year-old man was referred to the Maxillofacial Unit of the Novara Major Hospital with a 6-month history of a painless swelling in the right cheek. Clinical examination revealed a clearly visible, tender, slightly fluctuant mass, situated anterior to the masseter muscle and extended to the submandibular region. The patient underwent an ultrasound, a computed tomography, and a magnetic resonance imaging. Under general anesthesia with nasotracheal intubation, the patient underwent intraoral resection of BFP lipoma. DISCUSSION: The 2 major areas of discussion are the potential pitfall regarding the preoperative diagnosis and the close anatomic interrelation among the BFP, the FBB, and the PD. First, the spindle cell lipoma, one of the most common BFP lipoma variant, can be histologically and clinically similar to a well-differentiated liposarcoma, which can be recurrent and metastatic. This issue warrants that a careful workup of the tumorous mass of the buccal space and a BFP origin must be considered in every situation. Finally, according to the recent literature, the anatomic variations of the interrelation between the FBB and the BFP are classified into 2 groups: (1) FBB passing lateral to the BFP and (2) branches crossing inside the BFP. The anatomic variations of the interrelation between the PD and the BFP are classified into 3 groups: (1) PD passing lateral to the BFP, (2) PD crossing deep to the BFP, and (3) PD running along the superior border of the BFP.

Giant lipomatous tumors of the upper extremities--a series of 8 consecutive cases.

We present a series of eight consecutive patients evaluated in our department from 2002 to 2007 with giant lipomatous tumors (as defined in medical studies as greater than 5 cm) of upper extremities. There were three male and five female, ranged in age from 17 to 77 years (mean age of 55). The tumor's size ranged from 5 to 34 cm. All patients underwent total excision of the tumors with free margins. All specimens were sent to pathology: seven patients had benign tumors and one patient had liposarcoma. There were no recurrences of the tumors. Appropriate preoperative evaluation and complete surgical excision are mandatory for successful treatment of these tumors.

Lipoblastoma--an unfamiliar but important diagnosis. A case series and literature review.

Lipoblastoma and its infiltrative variant lipoblastomatosis are rare adipose tissue tumours seen in infants and children. Many surgeons are unfamiliar with these uncommon lesions and hence they are suboptimally treated. We report a case series of six patients in our tertiary paediatric hospital. Cases were reviewed retrospectively with reference to demographics, investigations, diagnosis and their management. Lipoblastomas are easily misdiagnosed and excision before proper investigations may result in incomplete resection, recurrence and further potentially mutilating surgery.

On lipoma of the buccal fat pad: report of two cases and review of the literature.

The buccal fat pad (BFP) has been the subject of numerous publications regarding its anatomy and clinical implications, however our interest in the pathology was aroused by two cases of lipoma originating from the BFP that were particularly interesting as one lipoma was congenital and the other recurred. A search of the international literature revealed a further 27 cases of BFP lipoma dating from 1848 to 2002. This suggests it is a rare entity but the authors suspect it to be under reported because of unfamiliarity with the possibility and the various atypical characteristics that were observed. Firstly, BFP lipomas appear to be congenital relatively often. Also, many are histological variants such as the spindle-cell lipoma, which could be associated with a more diffuse growth in the various extensions. As the deep extensions are not routinely removed due to the difficulty of the procedure, this could result in incomplete resection and recurrence. A possible explanation is the hypothesis that the BFP has a different embryological origin than subcutaneous fat. More importantly, well-differentiated liposarcoma of the BFP has also been described, which may be clinically and histologically indistinguishable from spindle-cell lipoma. Therefore, the authors recommend a careful workup of every mass of the buccal space with consideration of the BFP as a possible origin. Detailed knowledge of the anatomy and extensive MR-imaging are paramount in guiding the surgical approach by visualising the extent of growth in the various extensions, and determining if the radiological picture is suggestive of liposarcoma.

Lipoblastoma in children: an analysis of 5 cases.

Lipoblastoma is a very rare benign tumour that is caused by embryonal fat. The present five cases of lipoblastoma operated on during the years 1996-2005. The localization of the lipoblastomas in our series were very unusual. A six-monthold girl with giant mediastinal lipoblastoma; a two-year old boy with very rare lipoblastoma of the kidney; a three-year old boy with mesenterial lipoblastoma; a seven-year old boy with mesenterial lipoblastoma; and an eight-week old girl with perineal localization. Histological diagnosis can be difficult. The basic differential diagnosis is to be made between lipoblastoma, myxoid, and round cell liposarcoma. In our sample group of patients all lipoblastomas were successfully and completely removed and we did not see any recurrence of the tumours. In only one case was more radical surgery needed. One patient with mesenterial lipoblastoma had to undergo a 30 cm long resection of the small intestine.