Pulmonary adenofibroma: cytologic and clinicopathologic features of a rare benign primary lung lesion

A case report of adenofibroma arising from the seminal vesicle: A rare giant pelvic mass

Primary seminal vesicle tumors are extremely rare. Several rare pathological types of primary seminal vesicle tumors have been reported, such as adenocarcinoma, but there is no report on adenofibroma. We report the first case of adenofibroma arising from the seminal vesicle. A 50-year-old man, with no history or clinical evidence of any other tumors, accidentally found a pelvic mass during an ultrasound examination. As the mass grew, the patient developed mild constipation, without genitourinary or other symptoms. All laboratory examinations were normal. MRI of the pelvis revealed a mixed density, measuring 11.7×9.9×8.2cm, well circumscribed mass. The rectum, bladder, prostate and lymph nodes were normal. We successfully performed the open surgery and removed the mass. Histopathological results confirmed that the mass was a primary seminal vesicle adenofibroma. In literature, we found that for biphasic differentiated tumors, it is easy to reduce the accuracy of pathological diagnosis because of insufficient puncture. Therefore, preoperative puncture biopsy for seminal vesicle tumors should be investigated further.

A Case of Pulmonary Adenofibroma Treated by Thoracoscopic Resection

Pulmonary adenofibroma is a rare biphasic tumor that contains epithelial and stromal components. We report a case of pulmonary adenofibroma in which the tumor was resected by thoracoscopic surgery and the diagnosis was established by histopathology. A 59-year-old woman with a past medical history of pyelonephritis visited our hospital for evaluation of an abnormal opacity on a plain chest x-ray during a comprehensive medical examination. A follow-up chest x-ray showed enlargement of the lesion, and the patient was referred to our department for further management. Chest computed tomography revealed a well-circumscribed nodule measuring 1.4 cm in diameter in the upper lobe of the left lung. The chest imaging findings suggested a benign tumor, but because of evidence of lesion enlargement and elevated serum carcinoembryonic antigen levels, we performed wide wedge resection of the left upper lobe by video-assisted thoracoscopic surgery, for diagnosis and treatment. The resected specimen was submitted for rapid pathological diagnosis during the operation, and a benign tumor, possibly sclerosing pneumocytoma, was suspected. Therefore, we completed the operation with wide wedge resection. The final histopathological diagnosis was pulmonary adenofibroma. The patient had an uneventful postoperative course, and at this writing, 6 months postoperatively, there has been no evidence of tumor recurrence. We have reported this case of pulmonary adenofibroma because the tumor is rare, has not yet been well-characterized, and has an unclear prognosis. Collection of data from a larger number of patients is necessary.

Pulmonary Adenofibroma: Clinicopathological and Genetic Analysis of 7 Cases With Literature Review

Introduction

Pulmonary adenofibroma (PAF), characterized by biphasic differentiation composed of gland-like space lined by respiratory epithelium and stromal spindle cells, is a rare benign tumor of the lung. PAF was reported infrequently and inconsistently with diagnostic criteria and withstood higher risk of misdiagnosis as solitary fibrous tumors (SFTs) due to their morphological resemblance. In this study, we report seven cases of PAF with gene sequencing results and summarize the data of previous literature.

Materials and Methods

Seven cases of PAF with surgically resection samples were collected from Pathology department of West China Hospital, Sichuan University between 2009 to 2020. Immunohistochemical studies were performed in all cases and 3 cases underwent a 425-gene panel next-generation sequencing (NGS).

Results

Five female and two male patients were included in this study, with an average age of 51 years. All the patients were asymptomatic, and the lesion was identified on routine chest radiography. The tumor size measured by computed tomography (CT) ranged from 0.5 to 2.7 cm. Gland-like structures were mostly positive for glandular epithelium markers. The spindle cells in stroma expressed Desmin, SMA, ER and PR in 3 of 7 cases. No well-recognized molecular abnormalities can be identified by NGS in the 3 cases. To date, all the patients are alive, with no evidence of recurrence and metastasis.

Conclusion

PAF is a unique benign pulmonary tumor with low incidence. Biphasic morphology, IHC stains along with molecular detection is of great significance to make a clear diagnosis.

Pulmonary Adenofibromas: A Clinicopathologic Correlation of 13 Cases

Thirteen cases of primary pulmonary adenofibromas are presented. The patients are 8 women and 5 men between the ages of 41 and 73 years (average: 57 y). The patients presented with nonspecific symptomatology or their tumor was identified during routine chest films. A wedge resection was performed in all cases with lymph node sampling. Grossly, the tumors varied in size from 1 to 2.5 cm in greatest dimension. The entire tumor was histologically evaluated in all cases. All the tumors shared similar histologic features namely leaf-like/phyllodes-like growth patterns with varying areas of sclerosis, focal inflammation, and entrapped epithelium. A wide panel of immunohistochemical studies was performed including epithelial, neural, muscle, and vascular markers, all of which showed negative staining. The tumors were positive only for vimentin in the stroma and keratin in the entrapped epithelium. Further evaluation in 6 cases using in situ hybridization for the solitary fibrous tumor was performed and was negative. Clinical follow-up in all the patients showed no evidence of recurrence or metastatic disease, during a period of 12 to 36 months. The current cases highlight the unusual occurrence of pulmonary adenofibromas and the importance of separating these tumors from other tumors that may have the potential to recur or metastasize. The use of proper immunohistochemical stains/molecular analysis aids in the proper classification of these tumors.

Pulmonary Adenofibroma Manifesting as Two Nodules in Different Lobes of the Lung: A Case Report

Pulmonary adenofibroma is a rare tumor, with a few reported cases in the literature. Radiologically, the lesion appears as a solitary pulmonary nodule in most cases, and the multiplicity of this disease entity is extremely rare. We present an unusual case of pulmonary adenofibroma in a 71-year-old woman manifested as two nodules in different lobes of the lung on CT. Histopathological and immunohistochemical examinations are needed to establish the definitive diagnosis of pulmonary adenofibroma.

Pulmonary adenofibroma in a sika deer

A solitary firm nodule was found in the lung of a sika deer (Cervus nippon yesoensis). Histologically, it was a biphasic lesion composed of epithelial and stromal cell elements and exhibited a leaf-like growth pattern. The epithelial cells were immunohistochemically positive for pancytokeratin, cytokeratin 7, napsin A, and thyroid transcription factor-1, and the stromal cells were positive for vimentin and partially positive for desmin and α-smooth muscle actin. These observations were consistent with pulmonary adenofibroma, which is an extremely rare lesion in humans. To the best of our knowledge, this is the first reported case of pulmonary adenofibroma in an animal.

Synchronous Pulmonary Adenofibroma and Solitary Fibrous Tumor: Case Report and Review of the Literature

Pulmonary adenofibroma (PAF) is a rare neoplasm that may be related to solitary fibrous tumor (SFT). A subset of PAFs harbor the NAB2-STAT6 fusion that is typical of SFT, but a significant proportion do not. Their distinction is clinically important as SFTs can potentially have an aggressive clinical course, while there has been no report of a PAF behaving in a malignant fashion. We report a case of a 60-year-old male who developed a SFT and PAF in the same lung. The SFT harbored a NAB2-STAT6 fusion, while the PAF did not have any identifiable fusion. This case represents the first instance of a single patient with both of these tumors occurring simultaneously in the same lung.

Recurrent NAB2-STAT6 gene fusions and oestrogen receptor-α expression in pulmonary adenofibromas

AIMS

Pulmonary adenofibromas are rare benign fibroepithelial tumours of the lung with unknown histogenesis and an indolent clinical behaviour. Their stroma resembles that of solitary fibrous tumours, whereas the glands are composed of respiratory epithelium organized in a phyllodes-like architecture. Differentiation of pulmonary adenofibromas from other more aggressive intrathoracic tumours is clinically relevant. However, their biology is unknown. Here, we sought to characterize pulmonary adenofibromas at a clinicopathological level and to define whether they could be underpinned by a highly recurrent somatic genetic alteration akin to tumours with similar morphology.

METHODS AND RESULTS

Seven pulmonary adenofibromas were subjected to immunohistochemical analysis for thyroid transcription factor 1 (TTF1), napsin A, cytokeratin 7, E-cadherin, CD99, CD34, CD31, STAT6, oestrogen receptor (ER), progesterone receptor, androgen receptor, bcl-2, and vimentin, as well as electron microscopy and capillary sequencing on microdissected samples to evaluate the presence of NAB2-STAT6 fusion genes and MED12 exon 2 mutations in their discrete components. A control group comprising pulmonary solitary fibrous tumours, pulmonary hamartomas and breast fibroadenomas was also analysed. We confirmed that the stromal elements of pulmonary adenofibromas pertain to the fibroblastic lineage, and show ER overexpression in 71% of cases, whereas the epithelium consists of TTF1-positive, E-cadherin positive bronchiolar elements. A highly recurrent NAB2-STAT6 fusion variant (exon 4-exon 2) was detected in the stroma but not in the epithelium. No MED12 mutations were identified.

CONCLUSIONS

Here, we demonstrate that pulmonary adenofibromas are neoplastic lesions harbouring the molecular hallmark of solitary fibrous tumours.

A case of pulmonary hamartoma with distinctive histopathological features: a discussion of its differential diagnosis and histogenesis

We herein describe a case of a benign pulmonary tumor with distinctive histopathological features. A 55-year-old Japanese male presented with a well-demarcated tumor in the left upper lobe of his lung, which gradually increased in size from 18 to 21 mm over 24 months. The resected tumor consisted of an epithelial component of compact irregular glands and mesenchymal component of fascicles between the glands. The differentiation of pneumocytes and smooth muscle cells was immunohistochemically detected in the epithelial component and the mesenchymal component, respectively. No mitosis, necrosis, bleeding, or invasion was observed. A histopathologic diagnosis of fibroleiomyomatous hamartoma was made. We also review previously reported tumors with similar histopathological features and discuss their differential diagnosis and histogenesis.

Pulmonary adenofibroma: clinicopathological study of 3 cases of a rare benign lung lesion and review of the literature

Pulmonary adenofibroma is a rare benign biphasic tumor of the lung composed of epithelial and stromal components. We report 3 cases of this unusual lesion of lung in a male (25 years old) and 2 female (40 and 55 years old) patients. Breathlessness on exertion and mild left-sided chest pain of 1 month's duration were the main concerns in 2 patients, whereas the third had cough and hemoptysis for 3 months. Chest radiograph and computed tomography scan revealed a well-circumscribed, subpleural homogenous mass in left lower chest fields in 2 cases and solid-cystic lesion in left upper lobe in the third patient. All 3 patients underwent lobectomy, following biopsy in 2 cases. Histology revealed a well-circumscribed lesion composed of complex glandlike spaces lined by cuboidal to columnar epithelium surrounded by a hyalinized spindle-cell fibroblastic proliferation reminiscent of adenofibroma of the female genital tract or fibroadenoma of the breast. Immunohistochemical examination supported the diagnosis of a benign pulmonary adenofibroma. All 3 patients were are alive and doing well with no evidence of recurrent or metastatic disease. Diagnosis on biopsy can be challenging and may be misinterpreted as well-differentiated adenocarcinoma with extensive fibrosis or low-grade sarcoma. Frozen-section consultation will be a valuable adjunct in planning for limited lung resection of this benign lung lesion. Although we described 3 cases of pulmonary adenofibroma, still this is the largest published series of this rare entity till date. The possible histogenesis and various differential diagnoses are discussed along with literature review.