Fine-needle aspiration of a well-differentiated papillary mesothelioma in the inguinal hernia sac: A case report and review of literature

Pitfalls in Frozen Section: A Case of Incidental Papillary Mesothelioma

Well-differentiated papillary mesothelioma is an uncommon benign, although potentially recurrent mesothelial lesion that occurs in the peritoneum of women over a wide age range. We recently encountered an incidental case sent for frozen section at the time of hysterectomy for endometrial carcinoma. Familiarity with this lesion will help prevent overinterpretation as a serous carcinoma.

Two Case Reports of Benign Testicular Mesothelioma and Review of the Literature

Mesothelioma is usually diagnosed in people over the age of 50 with large history of asbestos-related exposure. It is frequently located in pleural cavity, peritoneum, and pericardium. At the testicles the mesothelioma had been reported first in 1957 like a malignant non-germ-cells tumor. The objective is to present two case reports of benign testicular mesothelioma and review of the literature.

Well-differentiated papillary mesothelioma of the peritoneum: a diagnostic dilemma on fine-needle aspiration cytology

OBJECTIVES

Well-differentiated papillary mesothelioma of the peritoneum (WDPMP) is an uncommon subtype of epithelioid mesothelioma. Usually, WDPMP has a benign course, while a few patients have multiple recurrence and malignant transformation on long-term follow-up. The histology of WDPMP has been well studied compared with the cytology. Although accurate diagnosis is based only on histology and immunohistochemical stains, knowledge of the cytologic features of WDPMP in context with clinical and radiologic features is essential to predict a preoperative diagnosis and guide proper management, after excluding reactive mesothelial hyperplasia, malignant mesothelioma, and serous neoplasms of the ovaries and peritoneum. Surgical excision gives a favorable outcome.

METHODS

We describe a case of 28-year-old woman who sought treatment for chronic lower abdominal pain, dysuria, and dyspareunia.

RESULTS

Radiologic findings suggested multiple metastatic peritoneal deposits. Ultrasound-guided fine-needle aspiration cytology showed many papillae, tubulopapillary and spheroid groups, monolayered pavement-like sheets, and many dispersed cells. Papillae showed many layers of round to ovoid cells, with minimal atypia. Atypical mitoses and necrosis were not found. A cytologic diagnosis of WDPMP was suggested. After complete resection of all the tumor nodules, histopathology and immunohistochemical findings were compatible with WDPMP. On follow-up, she developed tumor recurrence at 9 months and was managed successfully with adjuvant chemotherapy.

CONCLUSIONS

This article highlights the cytologic features of WDPMP with relevant review of the literature and differential diagnosis.

Well-differentiated papillary mesothelioma manifesting in a hernia sac

Well-differentiated papillary mesothelioma (WDPM) is a tumor of uncertain malignant potential that usually occurs as a multifocal lesion of the female peritoneum, and is incidentally found at the time of surgery. We present here a multifocal case that had arisen from the lining of a hernia sac. To our knowledge, only four cases of this event have been previously described. A review of the five cases reported, including our case, revealed that the mean age of the patients was 56.6±8.35 years. There was predominance in men (4:1). In four cases, the lesion was incidental. Most tumors were found in inguinal hernias. Four cases presented with gross abnormalities in the hernia sac. All the five patients were alive with no evidence of WDPM after a mean follow-up of 38.6 months. Extensive sampling of this rare lesion helps to rule out an epithelial malignant mesothelioma and prevents overtreatment.

Abdominopelvic washings: A comprehensive review

Intraperitoneal spread may occur with gynecological epithelial neoplasms, as well as with non-gynecological malignancies, which may result in serosal involvement with or without concomitant effusion. Therefore, washings in patients with abdominopelvic tumors represent important specimens for cytologic examination. They are primarily utilized for staging ovarian cancers, although their role has decreased in staging of endometrial and cervical carcinoma. Abdominopelvic washings can be positive in a variety of pathologic conditions, including benign conditions, borderline neoplastic tumors, locally invasive tumors, or distant metastases. In a subset of cases, washings can be diagnostically challenging due to the presence of co-existing benign cells (e.g., mesothelial hyperplasia, endosalpingiosis, or endometriosis), lesions in which there is only minimal atypia (e.g., serous borderline tumors) or scant atypical cells, and the rarity of specific tumor types (e.g., mesothelioma). Ancillary studies including immunocytochemistry and fluorescence in situ hybridization may be required in difficult cases to resolve the diagnosis. This article provides a comprehensive and contemporary review of abdominopelvic washings in the evaluation of gynecologic and non-gynecologic tumors, including primary peritoneal and mesothelial entities.

Peritoneal mesothelioma masquerading as an inguinal hernia

We report a case of an 80-year-old man who presented with a right inguinal hernia that appeared incarcerated. On exploration a sausage shaped mass was found in the sac, which was debulked and histologically shown to be a well differentiated malignant peritoneal mesothelioma. Rare tumours may present as inguinal hernias and palliative debulking may be effective when they present in inguinal hernia sacs.

Peritoneal mesothelioma masquerading as an inguinal hernia

We report a case of an 80-year-old man who presented with a right inguinal hernia that appeared incarcerated. On exploration a sausage shaped mass was found in the sac, which was debulked and histologically shown to be a well differentiated malignant peritoneal mesothelioma. Rare tumours may present as inguinal hernias and palliative debulking may be effective when they present in inguinal hernia sacs.

Paratesticular mesothelioma. Report of a case with comprehensive review of literature

Paratesticular mesotheliomas are rare tumors with 223 cases described so far. The sole plausible causative factor so far ascertained in the pathogenesis of these tumors is asbestos, which however is found in only around 30% to 40% of such cases. The age range of affected individuals is wide, mostly adults and the elderly, but also includes young people and children. The most common presenting symptom is either hydrocele of unknown origin or intrascrotal mass. When hydrocele is the presenting symptom, these tumors are often clinically overlooked and the diagnosis is delayed. Most paratesticular mesotheliomas arise in the tunica vaginalis, but primary tumors of the spermatic cord and epididymis are also on record. Tumors arising from the peritoneal mesothelium of a hernia sac are excluded from this group. The correct diagnosis is almost always made after histologic examination of the operative specimen. Immunohistochemistry and electron microscopy are always helpful and sometimes necessary tools for diagnosis. So far very few cases have been identified or suspected preoperatively on cytologic examination. Three clinicopathologic types of malignant mesotheliomas of the male genital tract are recognized: diffuse tubulo-papillary mesothelioma, well-differentiated papillary mesothelioma, and multicystic mesothelioma. The histologic subtypes are almost always pure epithelial or biphasic. The differential diagnosis is mainly with serous papillary tumors arising from Mullerian vestiges, but several diverse primary or secondary tumors also need to be considered. A clinicopathologic evaluation of a case of tunical diffuse mesothelioma in a 74-year-old male from the AMR Series is the starting point for this general review.