Mimicking Malignancy Research Articles

Distinguishing synovial sarcoma from benign and malignant mimics: MR Imaging indicators

Distinguishing synovial sarcoma from benign and malignant mimics: MR Imaging indicators

FOSB immunoreactivity in endothelia of epithelioid hemangioma (angiolymphoid hyperplasia with eosinophilia).

Accurate distinction of epithelioid hemangioma (EH) from its malignant mimics is paramount but remains challenging due to its wide morphological spectrum and lack of objective molecular markers. FOSB oncogenic activation was recently identified as a key event in endothelial proliferation. We sought to investigate the FOSB staining pattern in EH with angiolymphoid hyperplasia with eosinophilia (EH-AHLE) morphology and to evaluate its value in differential diagnosis of epithelioid vascular tumors. From the authors' files, 15 representative cases of EH-ALHE were selected and evaluated for their FOSB immunostaining pattern. Other vascular proliferations which can be morphological mimics were also tested: epithelioid hemangioendothelioma (EHE) (5 cases) and epithelioid angiosarcoma (EAS) (5 cases). All 15 cases of EH-ALHE showed strong and homogeneous FOSB nuclear expression in endothelial cells with ample cytoplasm and intracytoplasmic vacuoles. All cases of EHE and EAS lacked FOSB immunoreactivity or showed only incidental weak FOSB immunoreactivity in less than 5 nuclei per lesion. FOSB immunohistochemistry is sensitive in the diagnosis of EH-ALHE, and allows differentiation from its histological mimics. An immunohistochemical panel including not only pan-cytokeratin AE1/AE3 and endothelial markers, but also FOSB, helps in the diagnosis of epithelioid vascular tumors.

Chondromyxoid Fibroma Arising in Craniofacial Sites: A Clinicopathologic Analysis of 25 Cases.

Chondromyxoid fibroma (CMF) is a rare benign tumor, usually arising in the metaphysis of long bones in young adults. Occurrence in craniofacial bones presents a particular diagnostic challenge given its unusual location and resemblance to malignant mimics. We describe the clinicopathologic features of 25 cases of craniofacial CMF identified between 1999 and 2017. Patients were 14 men and 11 women, with median age of 44 years (range, 5 to 83 y). Sites of involvement were sphenoid (7), ethmoid (5), maxilla (3), occipital (2), nasal septum (2), palatine (2), temporal (2), orbit (1), and undisclosed skull (1). Tumor size ranged from 0.8 to 6.0 cm (median, 2.0 cm). Of the 21 tumors with available radiology, 15 arose on the bone surface with expansion into adjacent sinuses; 6 were intraosseous. Bony erosion/destruction was present in most (13/16) cases, and 7/12 showed calcification on imaging. Microscopically, most tumors showed a lobulated growth pattern with hypocellular central chondromyxoid areas and peripheral hypercellularity, though many samples were fragmented. Tumor cells had ovoid to tapered nuclei and abundant palely eosinophilic cytoplasm, frequently with stellate cell processes. Mitoses ranged from 0 to 2 per 10 high-power fields (median count, 0). None showed necrosis. Significant atypia was present in 2 cases, 1 of which was a previously radiated recurrence. Bone infiltration was present in 6 cases. Thirteen tumors had focal calcification, and 2 had foci of hyaline cartilage. All tumors were negative for keratin and GFAP (0/24), with frequent positivity for SMA (7/7) and occasional staining for EMA (5/24) and S-100 (2/24). Most patients underwent piecemeal excision or curettage (5/5 positive margins when reported). Follow-up data were available for 15 patients, and 5 suffered local recurrence. Craniofacial CMF poses diagnostic pitfalls including frequent aggressive radiologic features and lack of a specific immunophenotype. Tumors may recur, largely due to the difficulty of obtaining clear surgical margins in this anatomic region. Furthermore, propensity for local destruction and invasion can create significant morbidity.

Synovial sarcoma of the neck: A malignant mimic of a common benign cyst

Synovial sarcomas are rare malignant neoplasms arising from mesenchymal stem cells, comprising 8–10% of soft tissue sarcomas. One in three cases occur in those under 20 years old. The lower extremity and trunk are the most common sites, with less than 10% occurring within the head and neck region. They have a variety of clinical and radiological appearances, with occasional cystic degeneration. Here we present a case of a 9-year-old boy who presented with a presumed benign branchial cleft cyst seen on ultrasound and CT. A unilocular cyst was found adjacent to the lateral horn of the thyroid cartilage. When excised, the cyst was 4 cm with a variably thick wall of fleshy tissue containing straw-coloured fluid. Histologically, the cyst wall was composed of mitotically active spindle cells in fascicles separated by oedematous and collagenous stroma with occasional gland formation. Immunohistochemistry supported a diagnosis of synovial sarcoma, with positive epithelial membrane antigen (EMA), Bcl-2 and cytokeratin antigens, and was confirmed by fluorescence in situ hybridisation with a SS18 rearrangement. This case highlights the important consideration of malignant entities in common benign presentations.

Pediatric Testicular Hemangioma in a 10-Year-old: A Rare Entity That May Mimic Malignancy With Appraisal of the Literature

Capillary hemangioma is a rare benign lesion in the testicle, particularly in pediatrics. It can mimic malignancy, leading to radical orchiectomy. We present a case of a testicular hemangioma in a child, and review the literature on testicular hemangiomas in this age group. A hypervascular testicular lesion without elevated tumor markers may warrant intraoperative biopsy to direct surgical management, which may include testis-sparing surgery if amenable.

Histopathological Spectrum of Prostatic Lesions with Special Emphasis on Mimickers of Malignancy

Histopathological Spectrum of Prostatic Lesions with Special Emphasis on Mimickers of Malignancy

Mimics of Malignancy in Abdominal Imaging: Multisystem Radiology.

Benign and malignant diseases share many overlapping features at abdominal imaging; knowledge of the characteristic imaging features, clinical clues, and disease patterns of conditions that mimic malignancy can assist the radiologist in suggesting a nonmalignant diagnosis.

Oncocytic Renal Neoplasms on Resections and Core Biopsies: Our Approach to This Challenging Differential Diagnosis.

Distinguishing oncocytomas from their malignant mimics is very challenging. This review highlights our approach to classifying low-grade oncocytic tumors on both resections and biopsies. We also discuss how we use immunohistochemical stains in this challenging differential diagnosis.

Acute Necrotising Sialometaplasia

Introduction Acute Necrotising Sialometaplasia (ANSM) is a benign, rare and self-limiting inflammatory condition of salivary gland tissue which classically presents as a unilateral necrotic ulcer on the hard palate. The primary aetiology is trauma of minor salivary gland tissue which has been reported to occur following local anaesthetic infiltrations, surgery, heavy smoking, excessive alcohol consumption and violent vomiting such as in patients with bulimia. The most significant issue is that is may, both clinically and histologically, mimic malignancy which could potentially result in an incorrect diagnosis and unnecessary treatment. ANSM is self-limiting and usually heals spontaneously between 3-12 weeks without complication. Case description A 43-year-old Caucasian female was referred to the Oral and Maxillofacial Surgery department by her general practitioner following an eight-day history of a painful ulcer on the hard palate. Her medical history was unremarkable, and she was a non-smoker with a low alcohol consumption. On examination, there was a 1.0x1.5cm diameter 'punched out' ulcer on the left posterior hard palate which extended down to bone. An urgent incisional biopsy was undertaken which confirmed a diagnosis of ANSM and excluded dysplasia. The patient was reassured and subsequently discharged at an eight-week review following resolution of the lesion. Results and conclusions ANSM can present a diagnostic dilemma as it mimics malignancy both clinically and histologically. It is therefore vital that practitioners have an awareness of the condition and appreciate its benign and self-limiting nature to avoid unnecessary surgical intervention and patient distress. An urgent referral to a specialist in Oral and Maxillofacial Surgery or Oral Medicine is vital such that an incisional biopsy can be undertaken to confirm a diagnosis and exclude malignancy. Take-home message Clinicians should be aware of ANSM and understand the importance of an urgent referral to a specialist to exclude malignancy.

Inflammatory MyofibroblasticTumour of Ovary Simulating Malignancy with Review of Literature

Inflammatory myofibroblastic tumour (IMT) of ovary is an uncommon benign neoplasm that can mimic malignancy. It often occurs in children and young adults. Lung is the most common site of IMT. Precise etiology is not known but recent reports suggested the role of benign reactive process in its pathogenesis. A 32 year old female patient presented to the gynaecology out patient department with complaints of lower abdominal pain and increased frequency of micturition with burning since 15 days. On per abdominal examination, an irregular lump of 18 weeks size with restricted mobility was palpable in suprapubic region. Laboratoratory investigations revealed normocytic normochromic anaemia with neutophilic leucocytosis and raised ESR. Her serum CA 125 levels were slightly raised (44.30 u/ml). Imaging studies showed an infiltrating mass in the pelvis. The patient underwent total abdominal hysterectomy with bilateral salpingo oopherectomy and omentectomy. Histopathological examination of which revealed IMT of right ovary with extension to right parametrium and adjacent bladder. As IMT is a mimicker of malignancy due to its infiltrative growth. Histopathological examination is mandatory for its diagnosis and treatment. Misdiagnosis can lead to unnecessary extensive debulking surgeries and even chemotherapy. Rarity of this entity in the ovary has made this case worth reporting. DOI: 10.21276/APALM.1285

The value of 18F-FDG PET/CT in the distinction between retroperitoneal fibrosis and its malignant mimics.

To discuss the utility of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computerized tomography (PET/CT) in the diagnosis of idiopathic retroperitoneal fibrosis (iRPF). IRPF patients diagnosed between September 2011 and June 2016 were included. Retroperitoneal malignancy patients were included as control. The morphological features and FDG uptake of retroperitoneal lesions were measured along with lymph node (LN) mapping. Seventy-one iRPF patients were included. Fifteen lymphoma patients and 6 retroperitoneal metastatic malignancy patients were included as control. Significant differences in morphological features were observed between iRPF and lymphoma but not retroperitoneal metastatic carcinoma. Compared with malignancy, iRPF displayed a lower frequency of high-FDG-uptake retroperitoneal lesions (P = 0.017) and a lower mean maximum standardized uptake value (SUVmax) (P < 0.001). LNs located at axillary, retroperitoneal, supraclavicular, inguinal or peritoneal sites were more frequently observed in retroperitoneal malignancy, therefore, were defined as specific LNs. The area under the curve (AUC) for SUVmax was 0.893 with a sensitivity of 85.7% and a specificity of 80.3%, when the cut-off value of the SUVmax was 6.23. The AUC for the logistic regression model combining the lesions above renal arteries, the SUVmax and the number of specific LNs was 0.987 with a sensitivity of 90.5% and a specificity of 98.6%. The risk stratification model analysis indicated that most of the retroperitoneal malignancy patients were at moderate or high level, while most of the iRPF patients were at low risk. Retroperitoneal malignancy can mimic iRPF morphologically. 18F-FDG PET/CT can help to distinguish iRPF from retroperitoneal lymphoma and metastatic malignancy.

Paraduodenal pancreatitis: benign and malignant mimics at MRI.

Paraduodenal pancreatitis, also known as groove pancreatitis, is a rare form of chronic pancreatitis that masquerades as pancreatic adenocarcinoma affecting the pancreaticoduodenal groove, a potential space between the head of the pancreas, duodenum, and common bile duct. Two forms of groove pancreatitis have been described. The segmental form involves the pancreatic head with development of scar tissue within the groove, whereas the pure form affects the grooveonly, sparing the pancreatic head.Imaging findings of groove pancreatitis often overlap with primary duodenal, ampullary, or pancreatic neoplasms, which often results in a diagnostic challenge. In addition, paraduodenal pancreatitis can be mistaken for cystic pancreatic lesions, especially when there is involvement of the duodenal wall. Preoperative recognition of this entity is very important in order to avoid unnecessary procedures, although surgery, such as pancreaticoduodenectomy, may still be required to relieve obstructive symptoms. In this article, the pathophysiology and magnetic resonance imaging characteristics of paraduodenal pancreatitis and important benign and malignant mimics are discussed.

Testicular Seminoma and Its Mimics: From the Radiologic Pathology Archives.

Testicular seminoma is the most common malignant tumor of the testis. It classically manifests as a painless mass. Radiologic evaluation with high-frequency ultrasonography (US) is critical for diagnosis. Seminomas are usually homogeneously hypoechoic masses at US. In challenging cases, magnetic resonance (MR) imaging may help confirm that a mass is intratesticular and provide data for local staging. Computed tomography (CT) provides valuable information for staging, including the presence and size of retroperitoneal lymph nodes. Testicular seminoma is treated with radical inguinal orchiectomy and is highly curable even at advanced stages of disease. Several neoplastic and nonneoplastic conditions may mimic testicular seminoma at imaging. Benign mimics include segmental infarction, hematoma, infection, epidermoid cyst, adrenal rests, sarcoidosis, splenogonadal fusion, and sex cord-stromal tumors. Malignant mimics include nonseminomatous germ cell tumors, lymphoma, and metastases. These conditions are individually reviewed with emphasis on features that allow differentiation from seminoma. Spermatocytic tumor, formerly known as spermatocytic seminoma, accounts for only 1% of testicular tumors. It is distinct from classic seminoma, with unique histologic, molecular, and genetic features. It affects an older patient population than classic seminoma and demonstrates indolent clinical behavior. Radiologists serve a key role in diagnosis, staging, and surveillance of patients with seminoma. A thorough knowledge of related clinical, radiologic, and pathologic findings will help the radiologist contribute to high-quality interdisciplinary care of affected patients.

Benign breast lesions that mimic malignancy

Many benign and reactive lesions of the breast show morphological overlap with malignant lesions. These benign mimics of malignancy often present diagnostic challenges to even the most experienced pathologists. This review focuses on several benign lesions of the breast that mimic malignant entities. For each of these lesions, we describe the key morphological and immunohistochemical features, potential diagnostic pitfalls, and our approach to arriving at the correct diagnosis.

Clinical and Cytological Spectrum of Granulomatous Mastitis and Utility of FNAC in Picking up Tubercular Mastitis: An Eight-Year Study.

Granulomatous Mastitis (GM) is a rare, benign, inflammatory disease of the breast. It is a well known mimicker of malignancy, clinically and radiologically. Patients are often subjected to number of tests for the right diagnosis. Non-specific Granulomatous Mastitis (NGM) and Tubercular Mastitis (TBM) are chief among the various causes of GM. They are important to be diagnosed early as their treatment varies significantly. Fine Needle Aspiration Cytology (FNAC) is simple, patient friendly and primary investigation modality in cases of lump in breast. To find out the utility of FNAC in differentiating NGM and TBM. All cases of granulomatous mastitis diagnosed on cytology over eight years were retrospectively retrieved. The clinical and radiological history was obtained from the patient file. The slides were stained with haematoxylin and eosin stain as well as Leishman stains. Special stains like Periodic Acid Schiff (PAS) and Ziehl Neelsen (ZN) stain were used for fungus and Mycobacteriumtuberculosis respectively. Histopathological correlation of the available cases was done. Clinical presentation and cytological morphology of individual cases was studied in detail. Twenty one cases of GM obtained, of which 16 were NGM and five were TBM. Both diseases were common among young reproductive women who presented with unilateral breast lump of varying duration. Almost 25% of NGM and 60% of TBM has clinical suspicion of malignancy. About 30% had radiological suspicion of malignancy. Nearly 62.5% of NGM patients had painful swelling and none of tubercular mastitis patients had pain. About 31% of NGM patients underwent prior abscess drainage and 40% of TBM patients gave history of tuberculosis. Almost 6.25% of NGM and 60% of TBM had axillary lymphadenopathy. Cytologically epithelioid cells were identified in 100% of patients whereas, granulomas were seen in 62.5% and 80% of NGM and TBM smears respectively. Langhans giant cells were frequent among TBM and foreign body giant cell among NGM. Caseous necrosis was seen in 60% of TBM and absent in NGM smears. Though, NGM and TBM is said to have overlapping features, our study highlights few clinical and cytological differences which aid in differentiating the two entities at primary level. FNAC along with special stain must be advocated as the primary tool of diagnosis in cases of GM.

Round ligaman kaynaklı retroperitoneal inflamatuar myofibroblastik tümör

Objective: Inflammatory myofibroblastic tumor (IMT) is a rare tumor. The etiology and biological behaviour is controversial. It could be seen in many different anatomical sites, however it is commonly seen in the lungs, mesentery, genitourinary tract and retroperitoneum. Uterine round ligament is a very rare location for IMT. Case: We report the morphological, immunohistochemical and clinical features of an IMT which is located in the retroperitoneum / uterine round ligament of a young woman in this paper. Conclusion: It is essential to differentiate IMT from benign and malignant mimickers for providing an appropriate therapy and follow-up.

Focal nodular and diffuse haematopoietic marrow hyperplasia in patients with underlying malignancies: a radiological mimic of malignancy in need of recognition

To report the authors' experience of focal nodular haematopoietic marrow hyperplasia (FNHMH) and diffuse haematopoietic marrow hyperplasia (DHMH) clinically masquerading as skip, distant, or disseminated metastasis in seven patients with underlying malignant neoplasms. Five patients with FNHMH and two with DHMH mistaken radiologically as skip and disseminated metastasis, respectively, were compared and contrasted with four patients with osteosarcomas and two with chondrosarcomas harbouring skip metastasis, noting the temporal relationship with their haematological profile. FNHMH and DHMH were undetectable by plain radiography and computed tomography (CT) except one showing subtle sclerosis on CT. They showed either isointense or hyperintense, but not hypointense, attenuation at T1-weighted imaging, and all showed hyperintense attenuation at T2-weighted MRI relative to skeletal muscle. Of the five patients who underwent bone scintigraphy, one showed mildly increased uptake, and one out of two showed markedly increased 2-[18F]-fluoro-2-deoxy-d-glucose (FDG)-positron-emission tomography (PET) uptake. The rates for sarcoma skip metastasis by plain radiography, CT, MRI, and bone scintigraphy were 40%, 66.7%, 100%, and 66.7%, respectively. At MRI, 60% showed hypointense and 40% isointense attenuation at T1-weighted, 80% hyperintense and 20% hypointense attenuation at T2-weighted imaging. Combined FDG-PET and CT, which was performed in only one patient, failed to show the skip metastasis. Not every patient with FNHMH or DHMH received granulocyte colony-stimulating factor (GCSF), but all had low or falling haemoglobin levels, which may thus be the prime cause for HMH. Due to overlapping radiological features, FNHMH and DHMH are great radiological mimics of malignancy. In some cases, needle biopsy is required for their definitive differentiation.

Effect of Background Parenchymal Enhancement on Pre-Operative Breast Magnetic Resonance Imaging: How It Affects Interpretation and the Role of Second-Look Ultrasound in Patient Management

Background parenchymal enhancement (BPE) on breast magnetic resonance imaging (MRI) may either obscure or mimic malignancy. We evaluated the impact of BPE on the diagnostic performance of pre-operative MRI in breast cancer patients, and how second-look ultrasound (US) can help in guiding patient management. Two hundred fifty-three breast cancer patients with pre-operative MRI were included. In moderate or marked BPE, abnormal interpretation rate (38.9% vs. 12.2%) and biopsy rate (27.8% vs. 8.3%) were higher, and specificity (64.7% vs. 89.8%) was lower, compared with minimal or mild BPE (all p < 0.001). Visibility of MRI-detected additional suspicious lesions on second-look US did not differ between the two groups (86.7% in minimal or mild BPE vs. 77.1% in moderate or marked BPE, p = 0.296). Increased BPE was related to increased abnormal interpretation rate, additional biopsy rate and decreased specificity. Second-look US was useful in visualization of MRI-detected additional suspicious lesions, regardless of BPE.

The Pathology of Reactive Lymphadenopathies: A Discussion of Common Reactive Patterns and Their Malignant Mimics.

-Distinguishing between a reactive and a neoplastic lymphoid proliferation is a clinically significant task frequently performed by the surgical pathologist in routine practice. -To highlight common situations in lymph node pathology where reactive changes and lymphoma may be misdiagnosed. -Data sources are peer-reviewed journal articles, textbooks, and clinical experience. -This review aims to refresh and enhance the surgical pathologist's awareness of the shared and distinguishing features of select reactive and neoplastic lymphoproliferations, which in turn will allow the surgical pathologist to make more accurate diagnoses and avoid the pitfalls of misdiagnosis. This will be done by describing a selection of commonly encountered reactive histologic changes observed in lymph nodes, present the lymphomas with which they share overlapping features, outline the features that distinguish them, and describe an approach to making an accurate diagnosis and avoiding a misdiagnosis in each scenario.

Abdominopelvic washings in gynecologic pathology: A comprehensive review.

Abdominopelvic washings (APW) performed during gynecologic surgeries have become a common specimen evaluated by cytopathologists. Their role in staging of female genital tract tumors has changed significantly since they were first described, and continue to evolve. The ability of these washings to detect microscopic disease, even in the absence of gross disease, warrants the critical role that these washings play in the staging of certain female gynecologic tract tumors, allowing for optimal staging and subsequent treatment of the patient. Irrespective of the underlying pathology, the gamut of cytomorphologic findings that may be observed in APW is extensive, and ranges from benign lesions that may act as mimickers of malignancy, to both common and rare malignancies. This review discusses the changing role of APW in the staging of gynecologic tumors, and highlights the salient cytomorphologic features of these lesions, with emphasis in their correct identification, including cautionary notes to avoid over or misinterpretation. Diagn. Cytopathol. 2016;44:1039-1057. © 2016 Wiley Periodicals, Inc.