Primary paraganglioma of the lung

Data set for the reporting of pheochromocytoma and paraganglioma: explanations and recommendations of the guidelines from the International Collaboration on Cancer Reporting

BACKGROUND AND OBJECTIVES

The International Collaboration on Cancer Reporting (ICCR) is a not-for-profit to develop evidence-based, internationally agreed-upon standardized data sets for each anatomic site, to be used throughout the world. Providing global standardization of pathology tumor classification, staging, and other reporting elements will lead to improved patient management and enhanced epidemiological research.

METHODS

Pheochromocytoma and paraganglioma are uncommon and are frequently overlooked in registry data sets. Malignant criteria have previously been defined only when there was metastatic disease.

RESULTS

With recent recognition of a significant inheritance association and the development of risk stratification tools, this data set was created in order to obtain more meaningful outcomes and management data, using similar criteria across the global pathology community. Issues related to key core and non-core elements, especially clinical hormonal status, familial history, tumor focality, proliferative fraction, adverse or risk stratification features, and ancillary techniques, are discussed in the context of daily application to these types of specimens.

CONCLUSIONS

The ICCR data set, developed by an international panel of endocrine organ specialists, establishes a pathology-standardized reporting guide for pheochromocytoma and paraganglioma.

Primary pulmonary paraganglioma: Two cases

Paraganglioma is a rare tumor originating from extra-adrenal chromaffin cells. Primary pulmonary paraganglioma can also be seen in pediatric patients. Due to its endobronchial localization, morphological features, and neuroendocrine immunohistochemical profile, primary pulmonary paraganglioma can be confused with carcinoid tumor. Primary pulmonary paraganglioma should be considered in the differential diagnosis of endobronchial tumors and necessary precautions should be taken, considering that it may be functioning. In appropriate cases, bronchial sleeve resection provides curative treatment. In this article, we present two cases: First was a functioning primary pulmonary paraganglioma that underwent lobectomy and second was an entirely endobronchial tumor without any extra-bronchial spread that underwent bronchial sleeve resection.

Genetics and imaging of pheochromocytomas and paragangliomas: current update

Pheochromocytomas (PCCs) and paragangliomas (PGLs) are rare, heterogeneous neuroendocrine neoplasms of the autonomous nervous system of chromaffin cell origin that may arise within the adrenal medulla (PCCs) or the sympathetic and parasympathetic paraganglia (PGLs). Currently referred to by the umbrella term pheochromocytomas-paragangliomas (PPGLs), these distinct tumors are characterized by specific histopathology as well as biological and clinical profiles. PPGLs may occur as part of hereditary syndromes (40% of cases) or as sporadic tumors. Currently, there are 12 different hereditary syndromes with characteristic genetic abnormalities, at least 15 well-characterized driver genes and distinct tumor metabolic pathways. Based on the Cancer Genome Atlas (TCGA) taxonomic schemata, PPGLs have been classified into three main clusters of specific genetic mutations and tumor pathways with clinical, biochemical, and prognostic implications. Imaging plays a pivotal role in the initial diagnosis, tumor characterization, evaluation of treatment response, and long-term surveillance. While MDCT and MRI help in the anatomic localization, SPECT, and PET using different radiotracers are crucial in the functional assessment of these tumors. Surgery, chemotherapy, and radiotherapy are currently available treatment options for PPGLs; antiangiogenic drugs are also being used in treating metastatic disease. Evolving knowledge regarding the different genetic abnormalities involved in the pathogenesis of PPGLs has identified potential therapeutic targets that may be utilized in the discovery of novel drugs.

Frequency and extent of cytokeratin expression in paraganglioma: an immunohistochemical study of 60 cases from 5 anatomic sites and review of the literature

The absence of cytokeratin expression in paraganglioma helps to differentiate it from other neuroendocrine neoplasms such as carcinoid tumor. Although rare cytokeratin positive paragangliomas have been reported, there are no large systematic studies of this phenomenon. The aim of this study was to determine the frequency and extent of cytokeratin expression in paragangliomas using a large cohort of cases from multiple anatomic sites. Immunohistochemical staining for keratin AE1/AE3 (mouse monoclonal, MAB3412; Millipore) and CAM 5.2 (mouse monoclonal, 349 205; Becton-Dickinson) was performed on whole-tissue sections from 60 resected paragangliomas from the head and neck (36), thorax (10), abdomen (8), intradural/epidural spine (5) and bone, left iliac (1). Cytokeratin expression was identified in only 2/60 (3.3%) cases. One was a mediastinal paraganglioma with moderate to strong expression of keratin AE1/AE3 and CAM 5.2 in <5% tumor cells. The other was a lumbar intradural paraganglioma positive for CAM 5.2 (moderate to strong, 80% of tumor cells) but negative for keratin AE1/AE3. All other paragangliomas (58/60, 96.7%) were negative for keratin AE1/AE3 and CAM 5.2. This study - the largest series of cytokeratin-stained whole-tissue sections of paragangliomas to date - supports the dictum that most paragangliomas are cytokeratin negative. Rare exceptions may be site-related.

Primary Pulmonary Paraganglioma Revealed by FDG PET/CT

Primary pulmonary paraganglioma is a rare type of extra-adrenal paragangliomas arising from neuroectodermal-derived paraganglionic tissue. We report herein the case of a 49-year-old woman with a round-like well-defined nodule in the right middle lobe detected by chest CT. FDG PET/CT also revealed this homogeneous nodule with increased FDG accumulation. Finally, the patient underwent right middle lobe resection, and the pathological findings demonstrated the diagnosis of pulmonary paraganglioma.

A case of endobronchial paraganglioma

Paragangliomas are rare lung tumours; endobronchial localisation is even more rare. This report describes the case of a 59-year-old patient with a symptomatic endobronchial paraganglioma successfully resected by means of pulmonary lobectomy. Recognition of this uncommon tumour can lead to a correct diagnosis and therapeutic strategy.

Pulmonary Mast Cell Tumor and Possible Paraganglioma in a Free-ranging Pacific Walrus ( Odobenus rosmarus divergens), Barrow, Alaska, USA

We describe a pulmonary mast cell tumor in a subsistence-harvested free-ranging Pacific walrus (Odobenus rosmarus divergens). Neoplastic cells effacing a focal area of pulmonary parenchyma were characterized by rare metachromatic granules and positive staining for C-kit. We also report co-occurrence of a peribronchial mass with a morphologic and immunohistochemical profile compatible with paraganglioma.

15 YEARS OF PARAGANGLIOMA: Pathology of pheochromocytoma and paraganglioma

Pathologists using their routine diagnostic tools can contribute both to the care of patients with pheochromocytoma/paraganglioma and to understanding the pathobiology of the tumors. They can document details of tissue organization and cytology that are accessible only by microscopy and can characterize admixtures of cell types that are morphologically distinct or show differential expression of immunohistochemical markers. Current roles and challenges for pathologists include differential diagnosis, identifying clues to the presence of hereditary disease, and effective communication of pathology information for clinical and research purposes. Future roles will increasingly involve risk stratification, identification of actionable targets for personalized therapies, and aiding the interpretation of molecular tests by helping characterize genetic variants of unknown significance. It remains to be determined to what extent the need for pathology input will be overshadowed by the availability of genetic testing and other molecular analyses at ever-decreasing cost, together with very effective clinical paradigms for risk stratification and patient care.

Primary paraganglioma of the lung: a case report and literature review

Only 22 cases of primary pulmonary paraganglioma have been reported previously. This report presents a case of paraganglioma that arose in the lung of a 38-year-old woman who presented with chest pain and paroxysmal cough with little sputum. Positron emission tomography-computed tomography scan demonstrated two homogeneous masses in the left lower lobe accompanied by multiple mediastinal lymph node metastases. After resection, gross pathological examination confirmed two solid masses, which had a yellow-grey complexion and decreased blood supply and that invaded the mediastinum. Immunohistochemical analysis confirmed the presence of several biological tumour markers. This is the first known report to describe the computed tomography imaging characteristics of a paraganglioma, thereby improving understanding of its morphological features and helping in the differential diagnosis of lung tumours.

Histologically benign but clinically malignant neoplasms in the thorax: CT-pathological overview

The purpose of this article is to review the computed tomography (CT) and histopathological features of uncommon primary neoplasms of the thorax that can manifest clinically malignant features (multiplicity of pulmonary nodules, an invasive nature, and metastases or recurrence after surgery) with little evidence of histological malignancy.

Left subdiaphragmatic paraganglioma supplied by contralateral right renal artery

INTRODUCTION

Paragangliomas are neuroendocrine tumors of the autonomic nervous system that arise from neural crest cells. Paragangliomas are typically extra-adrenal, non-functional and can be discovered incidentally, posing diagnostic and therapeutic challenges.

PRESENTATION OF CASE

We present the unusual case of a young man who presented with an acute abdomen secondary to small bowel obstruction, and was found to have an incidental left-sided subdiaphragmatic paraganglioma supplied by a branch of the contralateral right renal artery.

DISCUSSION

Emergent laparotomy revealed an internal hernia as the source of the small bowel obstruction. Initial attempts to remove an incidental left subdiaphragmatic mass were aborted because of bleeding. Subsequently, after preoperative superselective embolization of the feeding vessel arising from the right renal artery, the mass was successfully resected. Pathology was consistent with a paraganglioma.

CONCLUSION

This report highlights the rarity of the location and blood supply of an incidental left subdiaphragmatic paraganglioma found in the setting of a small bowel obstruction.

An incidentally discovered asymptomatic para-aortic paraganglioma with Peutz-Jeghers syndrome

Peutz-Jeghers syndrome (PJS) is an autosomal dominant inherited disorder characterized by mucocutaneous melanin pigmentation and gastrointestinal (GI) tract hamartomatous polyps and an increased risk of malignancy. In addition to polyposis, previous studies have reported increased risk of GI and extraGI malignancies in PJS patients, compared with that of the general population. The most common extraintestinal malignancies reported in previous studies are pancreatic, breast, ovarian and testicular cancers.We report the case of a 17-year-old boy who presented with generalized weakness, recurrent sharp abdominal pain and melena, had exploratory laparotomy and ileal resection for ileo-ileal intussusception. Pigmentation of the buccal mucosa was noted. An abdominal computed tomography scan (CT) revealed multiple polyps in small bowel loops. Gastroscopy revealed multiple dimunitive polyps in stomach and pedunculated polyp in duodenum. Colonoscopy revealed multiple colonic polyps. Pathological examination of the polyps confirmed hamartomas with smooth muscle arborization, compatible with Peutz-Jeghers polyps. CT scan guided left para-aortic lymph node biopsy revealed the characteristic features of extra-adrenal para-aortic paraganglioma. Although cases of various GI and extra GI malignancies in PJS patients has been reported, the present case appears to be the first in literature in which the PJS syndrome was associated with asymptomatic extraadrenal para-aortic paraganglioma. Patients with PJS should be treated by endoscopic or surgical resection and need whole-body screening.

Primary sclerosing neuroendocrine carcinomas of the lung: A clinicopathologic and immunohistochemical study of 10 cases

We describe 10 cases of primary well-differentiated neuroendocrine carcinomas (carcinoid tumor) of the lung with extensive sclerotic changes. The patients were 6 women and 4 men from 20 to 69 years of age. Clinically, patients had symptoms of bronchial obstruction such as cough, dyspnea, and chest pain. Surgical resection of the tumors was accomplished in all the cases. Histologically, all tumors corresponded to the well-differentiated type; however, in 4 cases, lymph node metastases were present. Immunohistochemically, all tumors showed positive staining for neuroendocrine markers, including chromogranin, synaptophysin, CD56, and broad-spectrum keratin. Follow-up information showed that 8 patients were alive after a period ranging from 1 to 5 years. The cases presented highlight an important feature of neuroendocrine carcinomas of the lung not previously addressed, one that may pose a problem not only in the diagnosis but also in the grading of these neoplasms.

Primary oncocytic adenocarcinomas of the lung: a clinicopathologic, immunohistochemical, and molecular biologic analysis of 16 cases

Sixteen cases of primary oncocytic adenocarcinomas of the lung are reported. The patients were 11 women and 5 men between the ages of 47 and 81 years (median, 75 years) with symptoms of cough, chest pain, and shortness of breath. Surgical staging disclosed 14 patients (88%) with stage I disease, 1 (6%) with stage II, and 1 (6%) with stage III. Histologically, all the cases displayed prominent oncocytic features with conventional growth patterns, including acinar, papillary, and bronchioloalveolar. Immunohistochemically, the tumors displayed positive staining for keratin 7, thyroid transcription factor-1, and mitochondrial antibody. Molecular studies showed 3 (20%) of 15 tumors with EGFR mutations and 3 additional cases with KRAS mutations. Clinical follow-up of at least 24 months was obtained in all patients and showed that 5 patients had recurrences, 2 patients died of tumor, and 2 other patients died of unrelated conditions. These cases represent an unusual variant of pulmonary adenocarcinoma.

Pulmonary paraganglioma manifesting as an endobronchial mass

Thoracic paragangliomas comprise only 1-2% of all paragangliomas, including the adrenal pheochromocytomas, and these tumors are mostly found in the mediastinal compartments (1). To the best of our knowledge, there is only one case report in the pathology literature of endobronchial involvement by a primary pulmonary paraganglioma (2). We report here on the CT and bronchoscopic findings of a case of pathologically proven endobronchial paraganglioma in a 37-year-old woman. In our case, bronchoscopy and CT demonstrated an endobronchial hypervascular mass, which indicated the presence of carcinoid or hypervascular metastasis based on the known incidence of such tumors.

Sclerosing Paraganglioma

Nineteen cases of a distinctive variant of paraganglioma characterized by extensive collagen deposition resulting in a pattern of growth that resembled an invasive malignant neoplasm are described. The patients were 3 men and 16 women, 32 to 69 years of age (mean, 50.5 years). The tumors were located in the carotid body region, parapharyngeal region, and mediastinum. Tumor size ranged from 2 to 6 cm in greatest diameter. Grossly, the tumors were described as rubbery to firm, tan-red, and with extensive areas of sclerosis. Histologic examination showed nests and cords of tumor cells separated by broad bands of fibrous tissue. The tumor cells ranged from round to polygonal with abundant cytoplasm to elongated spindle cells with scant cytoplasm. Nuclear cytomegaly was present focally enhancing the atypical appearance of the tumor cell population in 17 cases. Mitoses were sparse (<1 x 10 HPF), and there was no evidence of necrosis in any of the cases. Foci of vascular and perineural invasion were present in 2 and 4 cases, respectively. The most striking morphologic feature was the presence of irregular cords and bands of hyalinized fibrous tissue that compartmentalized the lesion into irregular nests, islands, or cords of tumor cells, imparting them with an infiltrative appearance. All the tumors showed positive immunostaining for chromogranin, synaptophysin, and monoclonal neuron specific enolase. S-100 protein stains identified a sustentacular cell network, whereas cytokeratin AE1/AE3 was negative in all cases. Clinical follow-up in 14 cases, ranging from 2 months to 20 years (mean follow-up, 6.6 years) showed evidence of local recurrence in 2 cases and the development of a separate tumor in the contralateral neck in 1 case. The remainder of patients were free of recurrence or metastasis following simple local excision. Because of the prominent sclerosis, a diagnosis of an invasive malignant neoplasm was initially considered in the majority of cases. Sclerosing paraganglioma should be included in the differential diagnosis of sclerosing lesions of the head and neck region and mediastinum. Appropriate immunohistochemical stains may be of aid for establishing the correct diagnosis.