FNA cytology of postoperative pseudotumoral lesions induced by oxidized cellulose hemostatic agents.

BACKGROUND: The use of topically applied hemostatic substances during surgery has become a common practice. In some cases, the material is not absorbed or induces a granulomatous reaction resulting in a pseudotumoral lesion. With imaging studies, it is not possible to differentiate this from a tumor recurrence or abscess. This study describes the authors' cytologic experience with a large series of pseudotumoral lesions induced by oxidized cellulose, one of the most commonly used hemostatic agents. Almost no cytologic descriptions are available in the medical literature. METHODS: Sixteen patients were evaluated, and the most common sites of fine-needle aspiration (FNA) were the mediastinum and thyroid surgical bed. Other locations were the axilla, neck, vulva, liver, and retroperitoneum. All these lesions appeared after surgical procedures in which oxidized cellulose was used as a topical hemostatic agent. The interval time between surgery and FNA varied from 4 to 46 months with a mean of 15 months. RESULTS: Cytology samples showed very similar findings. In all cases, foreign-body material with a variable granulomatous reaction was present. Oxidized cellulose was seen as laminated inorganic fragments and most often showed an elongated, quadrangular appearance. Amorphous, ill-defined fragments as well as a dense proteinaceous background with phagocytic cells were also present. CONCLUSIONS: The current study demonstrates that FNA cytology is a very useful method for the detection of pseudotumoral lesions induced by hemostatic agents. Pathologists must be familiarized with this finding because cytology permits easy differentiation from tumor recurrence.

Postchemotherapy Histiocyte-Rich Pseudotumor of the Spleen Simulating Residual Disease in a Patient With Non-Hodgkin Lymphoma on FDG PET/CT.

A 64-year-old man was treated with multiagent chemotherapy owing to high-grade non-Hodgkin lymphoma presenting as a bulky disease involving the spleen. Interim and posttreatment sequential FDG PET/CT scans revealed a residual splenic mass showing markedly intense FDG uptake suspected of a residual viable lymphoma. To definitely decide about the appropriate treatment, a laparoscopic splenectomy was performed. Histopathologic specimen was compatible with the rare diagnosis of postchemotherapy histiocyte-rich pseudotumor of the spleen, a potential pitfall simulating viable disease on FDG PET/CT.

A rare case of pseudotumor formation associated with methyl methacrylate hypersensitivity in a patient following cemented total knee arthroplasty.

Hypersensitivity to orthopedic implant materials has been well documented with potential catastrophic consequences if not addressed pre-operatively. The spectrum of reactions is wide, from mild non-specific pain with localized erythema to severe periprosthetic inflammatory destruction and pseudotumor formation. It is therefore essential to identify patients who have or are at risk for implant-associated hypersensitivity. Although metal sensitivity is commonly cited as the cause of these reactions, methyl methacrylate (MMA) has rarely been implicated. To the best of our knowledge, methyl methacrylate-associated pseudotumor formation has not yet been described. The following is a case report of a 68-year-old female who, after undergoing a routine cemented right total knee arthroplasty, developed a painless, enlarging mass during a 13-year period. This mass was found to be a pseudotumor in association with methyl methacrylate hypersensitivity. A review of pseudotumor pathogenesis, methyl methacrylate hypersensitivity, and preoperative preventative care is discussed.

Trunnionosis: the latest culprit in adverse reactions to metal debris following hip arthroplasty.

The imaging findings of periprosthetic soft tissue lesions (pseudotumours) have been typically defined in the context of newer second-generation metal-on-metal hip arthroplasty. More recently, similar findings have been described in the setting of non-metal-on-metal prostheses. Although uncommon, wear and corrosion between the metal surfaces at the head-neck ('trunnionosis') and neck-stem interfaces are the potential culprits. With modular junctions containing at least one cobalt chromium component frequently present in hip arthroplasty prostheses, the incidence of this mode of adverse wear may be higher than previously thought (irrespective of the specific bearing couple used). In the present report, we described a case of a severe adverse local tissue reaction secondary to suspected corrosion at the head-neck taper in a metal-on-polyethylene total hip arthroplasty and reviewed the literature. Knowledge of this topical entity should help radiologists facilitate early diagnosis and ensure early management of this potentially serious complication.

Inflammatory Pseudotumor Containing Kayexalate Crystals: A Case Report and Review of the Literature.

Kayexalate (sodium polystyrene sulfonate), a cation exchange resin often used to treat hyperkalemia, is known to produce gastrointestinal complications in a minority of patients. These complications range from mild gastrointestinal bleeding to perforation with acute abdomen. The typical histopathologic findings include mucosal ulceration, necrosis, and the presence of polygonal basophilic refractile crystals with a "fish scale" appearance. We present a unique case of Kayexalate crystals embedded in a perihepatic inflammatory pseudotumor, developing adjacent to a colostomy site in a 62-year-old woman following Kayexalate treatment. Microscopically, the lesion demonstrated a myofibroblastic proliferation rich in histiocytes and inflammation (lymphocytes, plasma cells, and eosinophils) as well as the presence of scattered typical Kayexalate crystals. This is the first report of extraintestinal Kayexalate identification in association with an inflammatory pseudotumor.

Metal-on-metal bearings, inflammatory pseudotumours and their neurological manifestations.

Metal-on-metal bearings have become more popular for hip arthroplasty in younger patients in the last 15 years. We present a review of the neurological consequences relating to such bearing surfaces illustrated by an appropriate case report. The mechanisms of increased metal ion production and pseudotumour formation are discussed. If unexplained neurology, hip/groin pain or a localised mass around the hip are present with a metal bearing hip then urgent referral to a specialist orthopaedic surgeon is warranted for consideration of exchange arthroplasty.

Development of hepatic pseudotumors for image-guided interventional and surgical research in a large animal model.

PURPOSE: Real-time image guidance and navigation have become increasingly important in an era of minimally invasive interventional and surgical procedures in the liver. To develop, test, and implement tools for real-time image guidance, the authors sought to create an in vivo tumor mimic with realistic imaging and treatment capabilities. MATERIALS AND METHODS: Hepatic pseudotumors were created by injecting 1-2 mL of alginate (a hydrocolloid) directly into the liver parenchyma in eight live pigs and two dog cadavers. Tumors were imaged by B-mode ultrasound (US), US elasticity imaging, multi-detector row computed tomography (CT), CT fluoroscopy, and magnetic resonance (MR) imaging to assess imaging capabilities. Procedures performed with the alginate pseudotumors included radiofrequency (RF) ablation and robotic needle guidance. RESULTS: Twenty-four hepatic pseudotumors were created, ranging in size from 10 mm to 28 mm at an average depth of 6 mm. Average time of preparation and insertion was 3 minutes. All tumors were palpable under the surface of the liver and were easily visible on B-mode US, US elasticity imaging, CT, and MR imaging. Tumors were successfully "treated" with RF ablation, and gross examination of the liver showed good encompassment of the tumor by the zone of thermal coagulation. In addition, the pseudotumors allowed for easy introduction of various types of needles, including RF ablation probes and experimental steerable needles. CONCLUSIONS: Alginate pseudotumors can easily be imaged and allow for different procedures to be performed. This model can be used for various research purposes.

Revision total hip arthroplasty due to pain from hypersensitivity to cobalt-chromium in total hip arthroplasty.

We report a case with hypersensitivity to CoCr in total hip arthroplasty coupled with conventional polyethylene and CoCr femoral head. The patient complained of left hip pain and systemic fever, and computed tomography imaging revealed a periprosthetic cystic lesion, so we performed revision total hip arthroplasty using a titanium stem and ceramic head and highly crosslinked polyethylene. Hip pain and cystic lesion disappeared 3 years after revision surgery.

Nanotoxicology of metal wear particles in total joint arthroplasty: a review of current concepts.

Metal-on-metal (M-M) joint replacement has raised concerns about the long-term effects of metal wear debris and corrosion products. This review summarizes the current concepts in biological reactivity to metal wear particles, ions, and corrosion products. Attention is focused on Co-Cr-Mo alloy since it is the most diffused and discussed material in arthroplasty.

Lymphocyte proliferation responses in patients with pseudotumors following metal-on-metal hip resurfacing arthroplasty.

Locally destructive soft tissue pseudotumor has been reported in patients following metal-on-metal hip resurfacing arthroplasty (MoMHRA). A delayed hypersensitivity reaction type IV to nickel (Ni), chromium (Cr), or cobalt (Co) has been suggested to play a role in its aetiology. The aim of this study was to investigate the incidence and level of metal-induced systemic hypersensitivity in patients with MoMHRA, both with and without pseudotumor by measuring lymphocyte proliferation responses to metals. A total of 92 patients were investigated: (1) MoMHRA patients with pseudotumors (nine female, one male); (2) MoMHRA patients without pseudotumors (30 female, 30 male); and (3) age-matched control subjects without metal implants (9 female, 13 male). The venous blood samples were collected for serum Ni, Co, and Cr ion level measurements and lymphocyte transformation tests (LTT). A higher incidence and level of enhanced lymphocyte reactivity only to Ni was found in patients with MoMHRA compared to the patients without MoM implants, reflecting exposure and immune reactivity. However, lymphocyte reactivity to Co, Cr, and Ni did not significantly differ in patients with pseudotumors compared to those patients without pseudotumors. This suggests that systemic hypersensitivity type IV reactions, as measured by lymphocyte proliferation response to these metals, may not be the dominant biological reaction involved in the occurrence of the soft tissue pseudotumors.

Factitial soft tissue pseudotumor due to injection of anabolic steroids: a report of 3 cases in 2 patients.

Traumatically induced inflammation or reactive processes are a relatively well-known phenomenon in both skin and soft tissue. These include panniculitides, fat necrosis, nodular fasciitis, and nonspecific fibrosis. Occasionally, traumatic reactions can be associated with factitial injury due to self-induced blunt trauma or injection of chemical agents. Factitial pseudotumors of soft tissue mimicking neoplasms and occurring in deep-seated locations are rare and not well recognized. We have had the opportunity to review a handful of cases over the years of soft tissue pseudotumors caused by self injection of steroids for the purposes of bodybuilding. Three of these cases in 2 patients are presented here. One patient developed a deep lateral thigh mass that was radiologically suspicious for sarcoma but upon core biopsy was found to be a lipogranulomatous reaction. The second patient had 2 masses occurring in the upper and lower extremity with an interval of 1 year between the two. This patient had both masses resected. The first had the appearance of a giant cell tumor with no immediately discernible foreign material. The second mass was initially presumed to be a metastasis from the upper extremity tumor and showed similar areas to the first specimen; however, it also had areas of obvious reactive features with foreign material. These features were found in the first tumor as well upon retrospective review. Both patients admitted to self injection of anabolic steroids after further history was sought by the clinicians. Deep soft tissue pseudosarcomas caused by injection of steroids are not well documented, and patient's reluctance to provide this information leads to difficulty in arriving at a correct diagnosis. Recognition of this possibility is important in avoiding incorrect diagnoses and unnecessary treatments.

Plasma cell granuloma in cyclosporine-induced gingival overgrowth: a report of two cases with immunohistochemical positivity of interleukin-6 and phospholipase C-gamma1.

We report two cases of gingival plasma cell granuloma in a 34-yr-old and 40-yr-old two male renal transplant recipients with cyclosporine A (CsA)-induced gingival overgrowth (GO). Histologically, these lesions were composed of mature plasma cells, showing polyclonality for both lambda and kappa light chains and fibrovascular connective tissue stroma. In addition to the fact that CsA-induced plasma cell granuloma is rare, the salient features of our cases were the secretion of interleukin-6 and overexpression of phospholipase C- gamma 1 of the tumor cells, which may explain the mechanisms of CsA- induced GO.

[Pseudotumoral enterocolic phlebitis of the cecum and rutoside. A case report]. / Phlébite entérocolique pseudotumorale du caecum et rutoside. Une nouvelle observation.

INTRODUCTION: Enterocolic phlebitis is an entity characterized by ischemic injury of the gastrointestinal tract caused by thrombophlebitis of the mesenteric veins without arterial involvement or systemic disease. EXEGESIS: We report a case of enterocolic phlebitis in a 57-year-old female treated by rutoside, revealed by intestinal obstruction related to a pseudotumoral lesion of the caecum. CONCLUSION: This case adds to the four cases of enterocolic phlebitis under rutoside already reported in the literature, suggesting a possible involvement of this drug in this rare disease.

Plasma Cell Granuloma in Cyclosporine-Induced Gingival Overgrowth: A Report of Two Cases with Immunohistochemical Positivity of Interleukin-6 and Phospholipase C-gamma1

We report two cases of gingival plasma cell granuloma in a 34-yr-old and 40-yr-old two male renal transplant recipients with cyclosporine A (CsA)-induced gingival overgrowth (GO). Histologically, these lesions were composed of mature plasma cells, showing polyclonality for both lambda and kappa light chains and fibrovascular connective tissue stroma. In addition to the fact that CsA-induced plasma cell granuloma is rare, the salient features of our cases were the secretion of interleukin-6 and overexpression of phospholipase C-gamma1 of the tumor cells, which may explain the mechanisms of CsA- induced GO.

Validation of volume measurements in esophageal pseudotumors using 3D endoluminal ultrasound.

The purpose of this study was to validate the accuracy and reliability of volume measurements using three-dimensional (3D) endoluminal ultrasound (ELUS) in canine pseudotumor esophageal specimens in vitro. Pseudotumors were created by injecting various volumes of US gel (0.1-1.0 ml) into canine esophageal specimens. A stepping-motor was used to pull either a 9, 12.5 or 20 MHz transducer through the lumen of the specimen at 1.5 mm/s. Images were downloaded to a LIFE computer system for 3D reconstruction. Volume measurements were made by two investigators and compared to spiral CT images. Averaging across all measurements, the average magnitude of error was 8.7% in individual US determinations and 11. 9% in CT measures. Volumes estimated from images spaced 0.5 and 1.0 mm apart, from images in the original and reconstructed planes, and from different scan frequencies, produced percentage errors that were not statistically significantly different from each other on ELUS. 3D ELUS can be used accurately and reproducibly to measure tumor volumes with a low mean percent in vitro.