Goyal M, Kodandapani S, Sharanabasappa SN, Palanki SD.

Department of Laboratory Medicine, Indo-American Cancer Institute and Research Centre, Hyderabad, India.

Abstract

Mesothelial cell inclusions in lymph nodes are of rare occurrence and can be mistaken as metastatic adenocarcinomas, mesothelioma or sinus histiocytosis. These are usually found in mediastinal and abdominal lymph nodes and are associated with effusions. We report a case of benign mesothelial cell inclusions in cervical lymph nodes, which was associated with chylous effusion, and immunohistochemistry revealed unusual weak cytoplasmic epithelial membrane antigen positivity in the cells.

Keywords: Adenocarcinoma, chylous effusion, epithelial membrane antigen, mesothelial cell inclusions

Cavallaro A, Berretta M, Lo Menzo E, Cavallaro V, Zanghì A, Di Vita M, Cappellani A.

Department of Surgery, University of Catania, Catania, Italy.

Abstract

Benign multicystic peritoneal mesothelioma (BMPM) is a rare disease with good short-term prognosis and rare malignant transformation. However, its biological significance remains unexplained. A neoplastic origin is considered by many authors to require a surgical excision, based on the high recurrence and progressive growth rate of the tumors. However, alternative or integrative treatment options have also been proposed. A 45-year-old woman presented to our unit with a history of occasional discomfort and pain in the left hip. On physical examination, we noticed a tough-elastic, fixed mass located in the iliac fossa. Computed tomography scan detected a mass with multiseptated cystic-like areas. Due to the similarity of these findings to a primitive sarcomatous tumor of the retroperitoneum, an arteriographic study was also performed. The patient underwent en bloc resection of the mass, including a segment of the sigmoid colon. The final pathologic diagnosis was cystic mesothelioma. Further studies are needed to better understand the etiology and pathogenesis of this rare disease, and to define a more tailored treatment plan.

Keywords: Benign multicystic peritoneal mesothelioma – Calretinin – Cytokeratin

Moore AJ, Parker RJ, Wiggins J.

Department of Respiratory Medicine, Wexham Park Hospital, Wexham, Slough, Berkshire, UK. a.moore@ic.ac.uk

Abstract

Malignant mesothelioma is a fatal asbestos-associated malignancy originating from the lining cells (mesothelium) of the pleural and peritoneal cavities, as well as the pericardium and the tunica vaginalis. The exact prevalence is unknown but it is estimated that mesotheliomas represent less than 1% of all cancers. Its incidence is increasing, with an expected peak in the next 10-20 years. Pleural malignant mesothelioma is the most common form of mesothelioma. Typical presenting features are those of chest pain and dyspnoea. Breathlessness due to a pleural effusion without chest pain is reported in about 30% of patients. A chest wall mass, weight loss, sweating, abdominal pain and ascites (due to peritoneal involvement) are less common presentations. Mesothelioma is directly attributable to occupational asbestos exposure with a history of exposure in over 90% of cases. There is also evidence that mesothelioma may result from both para-occupational exposure and non-occupational “environmental” exposure. Idiopathic or spontaneous mesothelioma can also occur in the absence of any exposure to asbestos, with a spontaneous rate in humans of around one per million. A combination of accurate exposure history, along with examination radiology and pathology are essential to make the diagnosis. Distinguishing malignant from benign pleural disease can be challenging. The most helpful CT findings suggesting malignant pleural disease are 1) a circumferential pleural rind, 2) nodular pleural thickening, 3) pleural thickening of > 1 cm and 4) mediastinal pleural involvement. Involvement of a multidisciplinary team is recommended to ensure prompt and appropriate management, using a framework of radiotherapy, chemotherapy, surgery and symptom palliation with end of life care. Compensation issues must also be considered. Life expectancy in malignant mesothelioma is poor, with a median survival of about one year following diagnosis.

Asghar S, Qureshi N, Awan A.

Department of Gyneacology, Unit-1, Sir Ganga Ram Hospital, Lahore. samina_asghar62@yahoo.com

Abstract

A large solitary multiloculated pelvic cyst in a 40-year-old woman with chronic pelvic pain was diagnosed to be a Multicystic Benign Mesothelioma (MBM) of peritoneum at laparotomy. Operative findings showed dense adhesions between uterus and bladder anteriorly, small intestines and pouch of Douglas posteriorly, a right ovarian cyst cm containing clear serous fluid and two nodular deposits were seen in the pouch of Douglas, small multiple deposits was found over the mesentery of small intestine and parietal peritoneum. Total abdominal hysterectomy with bilateral oophorectomy and infracolic omentectomy was done. During surgery, there was injury to the small intestine hence, resection of 10 inches of small intestine with re-anastomosis was carried out. Postoperative recovery was satisfactory. At 3 years follow-up, patient is symptom-free.

Cakir E, Demirag F, Aydin M, Unsal E.

Department of Pathology, Ankara Ataturk Chest Diseases and Chest Surgery Education and Research Hospital, Ankara, Turkey. arabaci.ebru@gmail.com

Abstract

Distinguishing malignant mesothelioma, adenocarcinoma and reactive mesothelial proliferation in both cytologic and surgical pathologic specimens is often a diagnostic challenge. Conventional cytomorphologic assessment is an important step in the differential diagnosis of these entities.
The pleural effusion cytologies from 40 cases of malignant mesothelioma, 40 cases of adenocarcinoma and 30 cases of reactive mesothelial proliferation diagnosed between 1997 and 2007 were reviewed. Twenty-seven cytologic features which are regarded as useful in the differential diagnosis of mesothelioma, adenocarcinoma and benign mesothelial proliferation were assessed. These cytologic features were subjected to a stepwise logistic regression analysis. Three features were selected to distinguish malignant mesothelioma from adenocarcinoma: giant atypical mesothelial cell (P = 0.0001), nuclear pleomorphism (P = 0.0001) and acinar structures (P = 0.0001), the latter two being characteristics of adenocarcinoma. The variables selected to differentiate malignant mesothelioma from reactive mesothelial cells were: cell ball formation (P = 0.0001), cell in cell engulfment (P = 0.0001) and monolayer cell groups (P = 0.0001), the latter being a feature of benign mesothelial proliferation. When these selected variables were subjected to a stepwise logistic regression analysis, the logistic model correctly predicted 90% of cases of benign mesothelial proliferation versus 97.5% of malignant mesothelioma and 92.5% of malignant mesothelioma versus 92.5% of adenocarcinoma.

Keywords: mesothelioma, adenocarcinoma, mesothelial proliferation, cytodiagnosis

Wilkinson L, De P, Bloxham C.

University Hospital of North Durham, North Road, Durham, UK. lsarkar@talk21.com

Abstract

Intestinal and extraintestinal complications of Crohn’s disease are well documented. Changes in the connective tissue within the intestinal wall and surrounding tissue including mesenteric fat are characteristically seen in resected and autopsy specimens. A rare and unusually florid mesothelial reaction in the surrounding small bowel serosa of a patient with a 2-year history of Crohn’s ileitis is described. The peritoneal surface of the ileal resection specimen displayed exuberant tubulo-papillary formations of the mesothelium, with superficial invasion of the underlying stroma. The case demonstrates the well-recognised difficult differential diagnosis between a benign mesothelial proliferation and malignant mesothelioma in a novel clinical setting, and the diversity of the extramural manifestations of Crohn’s disease.

Cuartas JE, Maheshwari AV, Qadir R, Cooper AJ, Robinson PG, Pitcher JD Jr.

Department of Musculoskeletal Oncology, University of Miami Miller School of Medicine, Miami, FL, USA.

Abstract

We report a case of a benign multicystic mesothelioma, which presented as a fungating mass through the anterior abdominal wall and arose in a cesarean-section scar without direct peritoneal involvement. A wide local excision was done and the diagnosis was confirmed by histopathology and immunohistochemistry. The postoperative course was uneventful and the patient is asymptomatic at 3 years’ follow-up. Although a history of previous abdominal surgery has been reported in a patient with benign multicystic mesothelioma, to the best of our knowledge, there is no report of a benign multicystic mesothelioma arising in a cesarean-section scar or presentation as a fungating skin mass. This unusual presentation may point to a traumatic or inflammatory etiology, although seeding of the wound during the previous surgeries is a more likely postulate. A pertinent review of the literature on benign multicystic mesothelioma is also presented.

Keywords: Benign multicystic mesothelioma – Peritoneal cyst – Peritoneal inclusion cyst – Peritoneal tumors – Cesarean-section scar lesions

Assaly M, Bongiovanni M, Kumar N, Egger JF, Pelte MF, Genevay M, Finci V, Tschanz E, Pache JC.

Department of Pathology, Geneva University Hospital, Geneva, Switzerland.

Abstract

Objective: To describe the cytological aspect of peritoneal washings in benign multicystic peritoneal mesothelioma (BMPM).

Methods: Three peritoneal washing specimens stained by standard cytological and histological procedures and analysed by light microscopy.

Results: The specimens showed an abundance of monomorphous mesothelial cells devoid of atypia or mitoses. The mesothelial cells were calretinin positive. They also showed numerous squamous metaplastic cells arranged in flat sheets or isolated cells. The background contained some inflammatory cells.

Conclusion: The combination of cytology of the peritoneal washing, histology (cell block and surgical specimen) and clinical history allow differentiation of BMPM from other cystic lesions (cystic lymphangioma and malignant mesothelioma).

Taheri ZM, Mehrafza M, Mohammadi F, Khoddami M, Bahadori M, Masjedi MR.

National Research Institute of Tuberculosis and Lung Disease, Department of Pathology, Shahid Beheshti University of Medical Sciences, Tehran, Iran. mtaheri@nritld.ac.ir

Abstract

Context: The differentiation of benign mesothelial proliferations from malignant mesotheliomas may be difficult, especially when evaluating small specimens from pleural biopsies.

Objective: To explore the potential value of 2 proliferative cell markers, Ki-67 and restrictedly expressed proliferation–associated protein 86 kDa (repp86), in distinguishing between malignant mesothelioma (MM) and benign reactive mesothelial hyperplasia (MH).

Design: Thirty-six cases of MM from 26 men and 10 women with a mean age of 62.9 years (range, 36–80 years) and 22 cases of benign reactive MH from 14 male and 8 female patients with a mean age of 51.5 years (range, 15– 88 years) were included in this study. The proliferative status of the lesions was assessed by immunohistochemistry using monoclonal antibodies to Ki-S2 (repp86) and Ki-S5 (Ki-67). The labeling indices were quantified.

Results: The mean labeling indexes for Ki-67 in MM and benign reactive MH were 24.6% (range, 1%–66%) and 6.23% (range, 0%–25%), respectively. The mean labeling indexes for repp86 in MM and benign reactive MH were 26.3% (range, 0%–50%) and 3.26% (range, 0%– 21%), respectively. The average proliferative cell count was significantly higher in MM compared with benign reactive MH (P < .001). Furthermore, both markers showed a significant correlation in their expression in MM and benign reactive MH (r = 77.5, P < .001). Sensitivities of 88% and 92% and specificities of 92% and 94% were obtained at a cutoff point of 9% for Ki-67 and repp86, respectively.

Conclusions: Used in combination, Ki-67 and repp86 appear to be useful markers in differentiating MM from benign reactive MH.

de Keizer B, Arsos G, Smit JW, Lam MG, Rinkes IH, Goldschmeding R, van Isselt JW.

Department of Nuclear Medicine, University Medical Center Utrecht, Utrecht, The Netherlands.

Abstract

Focal I-131 accumulation is generally a reliable indicator of functioning normal thyroid tissue or a differentiated thyroid cancer metastasis. However, physiologic accumulation of activity may also be observed in organs such as the intestinal tract, liver, and salivary glands. Extrathyroidal I-131 accumulation has been reported in various sites, such as ectopic gastric mucosa, gastrointestinal and urinary tract abnormalities, cysts (mammary, liver, kidney, and ovaries), and inflammation and infection foci. We report a case of focal I-131 accumulation in a benign cystic mesothelioma in a patient with follicular thyroid cancer.