Malignant smooth muscle tumors presenting as mediastinal soft tissue masses. A clinicopathologic study of 10 cases

Posterior mediastinal epithelioid leiomyosarcoma: Case report and literature review

Epithelioid type leiomyosarcoma is rarely encountered outside of the abdomen or uterus. We present a case of posterior mediastinal leiomyosarcoma in a 45-year-old male with back pain and bilateral lower extremity weakness. Magnetic Resonance Imaging of the thoracic spine revealed a heterogeneous posterior mediastinal soft tissue mass infiltrating the vertebral body and epidural space with resultant spinal cord compression and edema. Positron Emission Tomography showed no evidence of distant metastatic spread. Histopathological characterization revealed epithelial type leiomyosarcoma. Despite multiple subtotal resections, radiotherapy, and salvage chemotherapy with successful restoration of the patient's neurological function, the tumor burden remained significant. The patient was subsequently lost to follow up and the clinical outcome remains unknown. To our knowledge this is the first reported case of epithelioid type posterior mediastinal leiomyosarcoma presenting with spinal cord compression and edema.

Thymoma: Challenges and Pitfalls in Biopsy Interpretation

The interpretation of biopsy specimens in the diagnosis of thymoma is a subject that is generally not addressed in the literature. Even though the diagnosis of thymoma may seem to be an easy step in the assessment of these tumors, in reality, it is the biopsy specimen interpretation that will be use to determine course of action in any particular patient. It may determine whether a patient is a surgical candidate or on the contrary whether a patient may be benefited the most by medical therapy. In addition, there may be conditions in which all that is required is surgical resection without any further treatment, and that the evaluation of those conditions does not necessarily required the careful pathologic staging that thymomas need. In addition, it is important to highlight that in small biopsies, there are limitations not only in terms of the cellularity and other features that may not be present in such biopsy but also the limitation in term of immunohistochemical interpretation. Herein we have attempted to highlight numerous tumoral conditions that are frequently encountered in the daily practice of mediastinal pathology, some of them pose significant problems in separating them from thymomas. Needles to say, the entire spectrum of mediastinal pathology that may at any given time mimic thymoma is well beyond the scope of this review. Furthermore, we also herein emphasize the need for proper clinical and radiologic information and correlation in order to lead to a better interpretation of the biopsy specimen. The emphasis in this review is on thymoma and their possible pitfall and shortcomings while evaluating small biopsy specimens.

Mesenchymal Tumors of the Mediastinum: An Update on Diagnostic Approach

Mesenchymal tumors of the mediastinum are a heterogenous group of rare tumors with divergent lineages. Mediastinal mesenchymal tumors are diagnostically challenging due to their diversity and morphologic overlap with nonmesenchymal lesions arising in the mediastinum. Accurate histologic diagnosis is critical for appropriate patient management and prognostication. Many mediastinal mesenchymal tumors affect distinct age groups or occur at specific mediastinal compartments. Neurogenic tumors, liposarcoma, solitary fibrous tumor, and synovial sarcoma are common mesenchymal tumors in the mediastinum. Herein, we provide an update on the diagnostic approach to mediastinal mesenchymal tumors and a review of the histologic features and differential diagnosis of common benign and malignant mesenchymal tumors of the mediastinum.

Anterior Mediastinal Leiomyosarcoma: A Case Report and Literature Review

Primary mediastinal sarcomas are extremely rare. Additionally, mediastinal leiomyosarcomas account for approximately 9% of mediastinal sarcoma cases. Until date, only few cases of anterior mediastinal leiomyosarcomas have been reported. Herein, we report a case of an 85-year-old female with an anterior mediastinal mass of 15 mm. Histological examination revealed spindle tumor cells showing a fascicular growth pattern. Immunohistochemically, the tumor cells were focal positive for desmin, calponin, and α-smooth muscle actin. The pathological diagnosis was leiomyosarcoma. In conclusion, we encountered a case of a very rare leiomyosarcoma that occurred in the anterior mediastinum, and our report may contribute to the understanding of this disease.

Smooth Muscle Conditions of the Chest: A Clinical, Radiologic, and Pathologic Review

Smooth muscle conditions of the chest have diverse clinical and imaging manifestations and may involve nearly every thoracic structure. Differentiation among these conditions requires the integration of clinical, radiologic, and histopathologic data. Histologic examination in conjunction with immunohistochemistry is essential for differentiation from other spindle cell neoplastic mimics. Familiarity with these entities will ensure the inclusion of smooth muscle conditions in the differential diagnosis of thoracic soft tissue lesions and potentially guide the clinician in appropriate management. We review the clinical, imaging, and histopathologic features of thoracic smooth muscle-related conditions organized by the anatomic structures affected.

A case of leiomyosarcoma originating from a bronchogenic cyst: A case report

Mediastinal leiomyosarcoma is an aggressive tumor that primarily occurs in the posterior mediastinum. A bronchogenic cyst is a benign lesion that often develops in the mediastinum close to the thoracic trachea and has been reported to be the origin of certain malignancies. The present study reports an extremely rare case of an anterior mediastinal leiomyosarcoma that was considered to have originated from a bronchogenic cyst. An 82-year-old woman complained of chest pain, presenting an abnormal 70 mm mass shadow in the anterior mediastinum of a chest CT scan. Mediastinal tumor resection was performed and the tumor was diagnosed as a leiomyosarcoma. As the tumor was located adjacent to a bronchogenic cyst, it was considered to have originated from the remnant tissue of the cyst. Recurrent lesions were noted in the right lower lobe on CT scan 24 months after surgery.

Anterior mediastinal leiomyosarcoma mimicking thymoma: A case report

RATIONALE

Mediastinal leiomyosarcoma is very rare. In this paper, we report one case of anterior mediastinal leiomyosarcoma and retrospectively review the imaging findings of previously reported cases.

PATIENT CONCERNS

A 61-year-old male patient was admitted to our hospital due to the presence of a mediastinal space-occupying lesion for two years. Two years previously, chest computed tomography (CT) showed a small nodule in the anterior mediastinum. Twenty days previously, the CT examination was repeated at the local hospital due to respiratory symptoms, which showed a mass in the anterior mediastinum and interstitial inflammation of both lungs. After admission to our hospital, chest contrast-enhanced CT scanning showed a mass in the right anterior mediastinum that was approximately 3.3 × 5.2 cm2 in size that had a clear boundary, slightly heterogeneous internal density and heterogeneous enhancement.

INTERVENTIONS

The patient underwent a mediastinal lump resection.

DIAGNOSES

Finally, the pathological diagnosis was anterior mediastinal leiomyosarcoma.

OUTCOMES

The patient recovered well after the operation.

LESSONS

Accidental discovery of anterior mediastinal nodules should be followed up. Mediastinal leiomyosarcoma is common in the posterior mediastinum. Imaging shows a heterogeneous mass with a space-occupying effect that may easily involve adjacent mediastinal vessels or infiltrate surrounding organs.

A Case of Primary Mediastinal Leiomyosarcoma in Which Long-Term Survival Was Achieved

INTRODUCTION

Primary leiomyosarcomas (LMS) of the mediastinum are extremely rare malignant mesenchymal tumors developing from soft tissues or great vessels. We present a case of a primary leiomyosarcoma of the middle mediastinum in which long-term survival was achieved.

CASE REPORT

A 77-year-old man presented to us for examination with an extrapleural sign in his upper mediastinum on chest X-ray. Computed tomography (CT) revealed a well-circumscribed mass in the middle mediastinum. Thoracoscopic resection of the mediastinal tumor and immunohistological findings, which were positive for smooth muscle actin (SMA), HHF-35, vimentin, and desmin confirmed primary leiomyosarcoma. It recurred twice with solid right pulmonary metastases, which were resected. He was followed-up for a total of 9 years and 6 months from the first surgery with no signs of recurrence after his last surgery.

CONCLUSION

Surgical resection of both the primary tumor and pulmonary metastases remains the mainstay of treatment of primary leiomyosarcomas.

Thymoma and Synchronous Primary Mediastinal Seminomas with Florid Follicular Lymphoid Hyperplasia in the Anterior Mediastinum: A Case Report and Review of the Literature

Thymoma is the most common neoplasm of the anterior mediastinum and has malignant potential. Germ cell tumors (GCTs) found in the anterior mediastinum are usually benign, and malignant GCTs, such as seminomas, are rare. Histologically, mediastinal seminoma is indistinguishable from testicular seminoma except for site-associated morphological features such as lymphoid follicular hyperplasia. Therefore, excluding metastasis is very important. Recently, we treated a young adult patient with multiple thymic masses that occurred simultaneously. The patient underwent a thymectomy for the removal of the mediastinal masses, one of which was diagnosed as type B2 invasive thymoma, and two of which were diagnosed as primary mediastinal seminomas with massive follicular hyperplasia. The patient received adjuvant chemotherapy after surgical resection. To our knowledge, this is the first description of a thymoma and a mediastinal seminoma occurring simultaneously in the thymus. We present this case along with a literature review.

Intrathoracic glomus tumors and glomangiosarcomas: a clinicopathological and immunohistochemical study of 14 cases with emphasis on anatomic distribution

Fourteen cases of primary intrathoracic glomus tumor and glomangiosarcoma are presented. The patients were 9 men and 5 women aged 36 to 63 years (mean, 49.5 years). Clinically, 11 patients presented with nonspecific symptoms including cough, hemoptysis, chest pain, and back pain while 3 patients were asymptomatic. Anatomically, 9 tumors were in an intrapulmonary location, 3 in the mediastinum, and 2 in the trachea. Surgical resection was performed in all cases, and grossly the tumors varied in size from 1.5 to 4.5 cm in greatest diameter. Histologically, 12 cases corresponded to glomus tumor characterized by a homogenous proliferation of medium-sized cells with round nuclei and inconspicuous nucleoli and no evidence of mitotic activity or necrosis. In 2 cases, the presence of marked cellular pleomorphism, nuclear atypia, and mitotic activity was more in keeping with a diagnosis of glomangiosarcoma. The 2 glomangiosarcomas were located in the lung, one of which was associated with lymph node metastasis. Immunohistochemical stains for smooth muscle actin were positive in all cases while negative for epithelial, vascular, neuroendocrine, and neural markers. Clinical follow-up showed that all patients with a glomus tumor are alive and well after a period of 12 to 36 months after surgical resection. In contrast, the 2 patients with glomangiosarcoma died of tumor 24 and 36 months, respectively, after initial diagnosis. The current cases highlight the ubiquitous distribution of these tumors within the thoracic cavity and stress the importance of including these tumors in the differential diagnosis of thoracic neoplasms.

False-positive results in diagnostic immunohistochemistry are related to horseradish peroxidase conjugates in commercially available assays

False-positive results in diagnostic immunopathology can lead to unnecessary treatments. The purpose of this study was to do a side-by-side comparison of 10 different antibodies commonly used in the clinical laboratory altering only the horseradish peroxidase (HRP) conjugate. The automated Leica BOND-MAX platform was used to study serial sections from 203 tissues including controls compared in a blinded fashion using the HRP conjugates from Leica (Refine HRP), Ventana Medical Systems (Ultraview HRP), and Enzo Life Sciences (Polyview HRP). False-positive results, defined as signal from cases known to not contain the target, were noted in 23 (13%) of 171 cases with the Leica HRP, 62 (36%) of 171 cases with the Ventana HRP, and no cases with the Enzo HRP. Each data set was performed simultaneously allocating 1 tray for each of the 3 different HRP conjugates. HER2/neu analysis from triple-negative breast cancers were scored as positive by immunohistochemistry in 6 (24%) of 25 cases using either the Refine or Ultraview HRP and in 0 of 25 cases with the Enzo conjugate. It is concluded that false-positive results in a wide spectrum of diagnostic immunopathology tests can occur from 13% to 36% of cases with commonly used commercial assays based on the HRP conjugate.

Smooth Muscle Tumor Originating in the Pleura: A Case Report and Updated Literature Review

Smooth muscle tumors (SMTs) of the pleura are exceptionally rare. At present and to the best of these authors' knowledge, there are only 17 cases reported in the literature. We describe a case of a 51-year-old woman who complained of left sided pleuritic chest pain. Further, computed tomography (CT) revealed a left sided localized pleural-based mass involving the 9th rib. She underwent an interventional radiology guided percutaneous core biopsy of the lesion, which disclosed a “Smooth Muscle Tumor of Undetermined Malignant Potential (SMT-UMP).” A video-assisted thoracoscopic surgery (VATS) was performed for diagnosis and treatment purposes. Resections of the pleural-based mass and 9th rib were performed. SMT-UMP was the definitive diagnosis.

Mesenchymal tumours of the mediastinum--part II

This is the second part of a two-part review on soft tissue tumours which may be encountered in the mediastinum. This review is based on the 2013 WHO classification of soft tissue tumours and the 2015 WHO classification of tumours of the lung, pleura, thymus and heart and provides an updated overview of mesenchymal tumours that have been reported in the mediastinum.

Complete resection of a giant mediastinal leiomyosarcoma

Primary mediastinal leiomyosarcoma is an extremely rare malignancy, and the only opportunity for a cure lies with an aggressive surgical approach. We report a 66-year-old woman who underwent complete resection of a giant mediastinal leiomyosarcoma located on the bilateral diaphragm. The tumor encased the inferior vena cava and compressed the adjacent structures. Using cardiopulmonary bypass with 20 minutes of hepatic ischemia, the tumor was completely resected with combined resection and reconstruction of the surrounding structures. Because of the tumor size and location in the boundary area between thoracic and abdominal surgeries, the procedure necessitated the cooperation of many expert surgeons.

Superior vena cava syndrome due to a leiomyosarcoma of the anterior mediastinum: A case report and literature overview

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Leiomyosarcomas are rare causes of superior vena cava syndrome.

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Surgery is the treatment of choice.

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Specific approaches depend on the neoplasm's size and invasion of neighbouring tissues.

INTRODUCTION

Leiomyosarcomas are an infrequent cause of malignant superior vena cava syndrome (VCS).

PRESENTATION OF CASE

A 51-year old male patient was admitted for a three-day history of dyspnoea, dysphagia and erythema of the head and neck. Computed tomography and magnetic resonance imaging showed a lesion arising on the anterior mediastinum, which was in close proximity with a thrombus in the superior vena cava. Surgical excision was performed, including open resection of the primary tumour and an atrio-innominate vein bypass with 8-mm polytetrafluoroethylene (PTFE). Histology confirmed a leiomyosarcoma and postoperative radiotherapy sessions were performed. Due to evidence of enlargement of the thrombus, a second intervention was undertaken. In this procedure, a remainder of the primary tumour was resected and the superior vena cava reconstructed with an autologous pericardium patch. The patient recovered satisfactorily and was discharged on the seventh postoperative day, with no evidence for relapse after 10 months of follow-up.

DISCUSSION

Leiomyosarcomas comprise less than 2% of the tumours of the mediastinum and are a rare cause of paraneoplastic VCS. Male patients in their sixties are most commonly affected. Relapses seem to be common, and thus a careful follow-up is often recommended.

CONCLUSION

In spite of the limited data on the management of thoracic leiomyosarcomas, surgery is currently considered the mainstay of treatment.

Combined thymoma-thymic seminoma. Report of 2 cases of a heretofore unreported association

Two cases of a primary mediastinal tumor showing both thymoma and seminoma elements are presented. The patients were 2 men, aged 32 and 34 years, respectively. Clinically, both patients presented with symptoms related to their mediastinal masses, namely, chest pain and shortness of breath. Neither patient had any previous history of malignancy elsewhere. Diagnostic imaging revealed the presence of large anterior mediastinal masses. Both patients underwent thoracotomy with complete resection of their tumors. Grossly, the lesions measured 6 and 8 cm in greatest diameter, respectively and were tan and firm without areas of hemorrhage or necrosis. Both tumors appeared to be well circumscribed and grossly not involving any adjacent structures. Histologic sections showed the presence of distinct areas in the same tumor mass corresponding to conventional thymoma, whereas other areas corresponded to seminoma. Both components appeared to be present in almost equal proportions in the tumor. Immunohistochemical studies showed distinct labeling for each component: the thymoma component was positive for CAM5.2, Pax8, and cytokeratin 5/6; the seminoma component was positive for CAM5.2, SALL4, OCT3/4, and placental-like alkaline phosphatase. Both patients are currently alive and well 12 and 18 months after surgery, respectively. The cases herein described highlight the importance of ample sampling in mediastinal tumors and document for the first time the existence of combined thymoma-thymic seminomas.

Lipomatous tumors of the anterior mediastinum with muscle differentiation: a clinicopathological and immunohistochemical study of three cases

Three cases of primary lipomatous tumors of the anterior mediastinum with prominent muscle differentiation are presented. The patients were two women and one man between the age of 52 and 68 years. All patients presented with progressive shortness of breath. Radiographically, all patients demonstrated anterior mediastinal tumors which were surgically resected. In two cases, the gross findings were those of circumscribed tumors, while one lesion was described as an ill-defined and unencapsulated neoplasm. Histologically, two cases corresponded to a well-differentiated liposarcoma, while the third was a thymolipoma. Extensive areas of smooth muscle were identified in one of the liposarcomas, while the other contained areas of mature skeletal muscle. The thymolipoma displayed a prominent myoid component. Immunohistochemical studies for muscle markers including smooth muscle actin, desmin, and myoglobin showed positive staining in the corresponding components. Follow-up information showed that one patient with liposarcoma died 60 months after initial diagnosis, while the other two patients remain alive and well 16 and 36 months after diagnosis, respectively. The current cases highlight the spectrum of muscle differentiation that can be seen in adipose tumors of the anterior mediastinum and also emphasize the difficulty that such a diagnosis can pose when confronted with limited mediastinoscopic biopsies.

Inflammatory malignant fibrous histiocytoma associated with leukemoid reaction or leukocytosis: a comprehensive review

Inflammatory malignant fibrous histiocytoma (IMFH) associated with leukemoid reaction (LR)/leukocytosis is a rare entity. In this paper, we search PubMed for all known cases of IMFH associated with LR/leukocytosis in an attempt to draw conclusions about this variant's response to treatments and its pathophysiology. Medline electronic database was searched using key words such as malignant fibrous histiocytoma, leukemoid reaction, and leukocytosis. A total of 16 patients were found, twelve males (75%) and 4 female (25%), with a mean age of 62.6 years, ranging from 47 to 77. The mean survival was 770 days, ranging from 14 to 6570 days. Four patients were alive at last follow-up: 6570 days, 1095 days, 335 days, and 180 days, respectively. Of the 12 patients that expired, death occurred approximately 92 days after the onset of LR or leukocytosis, ranging from 3 to 334 days. We conclude that IMFH associated with LR/leukocytosis does not completely respond to chemoradiation. Overproduction of growth factors and cytokines by IMFH cells and their interactions with the inflammatory infiltrate seem to promote immunological effector cell's dysfunction and substantiate the development and growth of this neoplasm. A clear understanding of these molecular pathways is crucial in order to identify targets for potential therapy.

Primary mediastinal leiomyosarcoma

Primary leiomyosarcoma of the mediastinum is a very rare malignant mesenchymal tumor, which may arise in the soft tissue of the mediastinum or from the great vessels. Due to its rarity and nonspecific clinical symptoms, the correct diagnosis and proper management are often delayed and not well established. We report a 55-year-old woman with a large right-sided mediastinal leiomyosarcoma with adhesion to the pericardium and right middle lobe, which was completely removed via right thoracotomy along with pericardial resection and right middle lobectomy.

Primary pleural leiomyosarcoma with rapid progression and fatal outcome: a case report

Introduction

Leiomyosarcomas are neoplasms of smooth muscles that most commonly arise from the uterus, gastrointestinal tract, or soft tissue. Primary pleural leiomyosarcoma is extremely rare. To the best of our knowledge, only nine cases have been published to date. Because of the rarity of pleural leiomyosarcoma and its similarity (clinical and histological) to other pleural neoplasms, particularly sarcomatous mesothelioma, diagnosis is often difficult.

Case presentation

A 58-year-old North African man was admitted with complaints of dyspnea and chest pain to our hospital. Chest computed tomography revealed right pleural effusion and pleural thickening. A transthoracic needle biopsy yielded a diagnosis of leiomyosarcoma, and tumor cells were strongly and uniformly positive for vimentin, a smooth muscle actin at immunohistochemical analysis. A general examination did not show any metastatic lesions in other areas. One month after diagnosis, the tumor grew rapidly, with pulmonary invasion, and therefore he was treated only by palliative care. He died from respiratory failure one month later. Because no organ of origin of the leiomyosarcoma, other than the pleura, was detected, this case was diagnosed as a primary pleural leiomyosarcoma.

Conclusions

Although leiomyosarcoma originating from the pleura is rare, this entity is increasingly described. The purpose of presenting this case report is to raise awareness among clinicians to consider this clinical entity as a differential diagnosis when a pleural mass is identified.

Primary mediastinal "thymic" seminomas

Over the last half century, our knowledge on germ cell tumors (GCT) has increased dramatically. Tumors that at one time were supposed to originate exclusively from certain anatomic areas are now thought to occur in ubiquitous distribution. Nevertheless, because of their similar histopathologic features, the conventional classic evaluation of these patients will require careful clinical history as well as complete physical and radiologic evaluation. The emphasis in this manuscript will be to highlight the occurrence and overall characteristics of one of the most common GCTs in the mediastinal region-seminoma. A more detailed discussion of mediastinal GCTs is well beyond the scope of this review.

Primary leiomyosarcoma of the anterior mediastinum encasing the aortic arch, left common carotid and left subclavian arteries

A 66-year-old man presented with a one month history of hoarseness. Left recurrent nerve palsy and a left upper mediastinal mass were observed by an otorhinolaryngologist who referred the patient to our department. Chest computed tomography showed a superior mediastinal mass, which seemed to involve the left common carotid and left subclavian arteries from the greater curvature of the aortic arch. The innominate vein was compressed, and collateral circulation was well developed. The left upper lobe of the lung was also seemed involved. A mediastinal biopsy conducted via left thoracoscopy revealed a malignant spindle cell tumor. The mediastinum was irradiated (40 Gy), and surgical extirpation was subsequently undertaken 3 weeks later. The tumor was successfully removed without the use of extracorporeal circulation. Because only smooth muscle actin was focally but strongly expressed immunohistochemically, leiomyosarcoma was confirmed. The patient was discharged on day 14. A solitary left pleural metastasis was observed and resected 12 months after the surgery and the patient is well without further recurrence 16 months after the initial surgery.

Primary Smooth Muscle Tumor of the Pleura: A Clinicopathological Case Report with Ultrastructural Observations and a Review of the Literature

Primary smooth muscle tumor of the pleura is exceptionally rare. The authors describe a primary smooth muscle tumor of the pleura that was discovered incidentally on chest X-ray in a 73-year-old man. Magnetic resonance imaging demonstrated a 12 x 18 x 15-cm pleura-based mass arising from the posterior mediastinum. Computerized tomography (CT) guided needle cores from the pleura showed a primary smooth muscle tumor of undetermined malignant potential. Further excision of the whole tumor showed an intimate relation to pleura, and the diagnosis of leiomyosarcoma was made. The clinical, radiological, histopathological, immunohistochemical, and ultrastuctural findings were consistent with a primary smooth muscle tumor of the pleura. This is the seventh case in the literature of a primary smooth muscle tumor of the pleura, which, to the best of the authors' knowledge, is the first such case of the pleura to be diagnosed on CT-guided needle biopsy. In conclusion, this method of investigation is recommended since it is minimally invasive but has a rewarding yield in providing the most likely diagnosis, predicting prognosis, and management planning.

[Primary leiomyosarcoma of visceral mediastinum]

Primary leiomyosarcoma of the thorax is a rare malignant mesenchymatous tumour. Most of those tumours occurring in the mediastinum arise from the oesophagus and great vessels, whereas an appearance in the soft tissue of the mediastinum is extremely rare. The rare incidence of this tumour and its slow growth reflect the difficulties in differential diagnosis according to their histopathology and location. The most common treatment is surgical resection. The authors describe a case of a leiomyosarcoma arising from soft tissue of the mediastinum and present a review of the literature.

Late Paraplegia After Scoliosis Treatment

We report the case of a young girl treated at age 16 for a progressive scoliosis by posterior instrumented arthrodesis. Ten years later, she suddenly developed lumbar pain and paraplegia. The surgical procedure showed a mass infiltrating the vertebral canal and the dural sheath following a supralaminar hook. Histology revealed a diagnosis of leiomyosarcoma. The outcome was poor with a rapid and fatal extension of the tumor. There is nothing to justify a causal link between the scoliosis and the late onset of a malignant tumor. Nevertheless, we discuss the potential role of diagnostic irradiation consecutive to scoliosis monitoring during growth and the potential role of environmental carcinogens like metallic biomaterials. Finally, rapid intrusion of this extraspinal tumor into the dural sheath resulted in a confusing clinical picture and delayed the diagnosis and treatment of the tumor.

Cystic Adenomatoid Tumor of the Mediastinum

A case of adenomatoid tumor presenting as a mass in the anterior mediastinum is described. The patient was a 56-year-old woman with left side chest wall pain who showed a mediastinal mass on chest x-ray and CT scans. Thorough clinical and radiographic examination did not reveal any evidence of tumor elsewhere. At surgery, the tumor was found adjacent to the anterior pericardial reflection. Grossly, the tumor measured 5.5 x 5.5 x 3 cm and showed a homogeneous cut surface with numerous cystic structures that varied from 0.5 to 1.5 cm in greatest diameter. Histologic examination showed numerous cystic spaces lined by flattened or cuboidal epithelial cells. The walls of the cysts showed a proliferation of small canalicular structures lined by round to polygonal epithelioid cells with vacuolated eosinophilic cytoplasm. Immunohistochemical studies showed strong positivity of the epithelioid cells for AE1/AE3 cytokeratin, CK5/CK6, and calretinin. Stains for CK7, CK20, alpha-fetoprotein, CD31, carcinoembryonic antigen, MOC 31, and chromogranin were negative. Electron microscopic examination showed numerous long microvilli on the cell surface and abundant tonofilaments/desmosomal plaques in the tumor cells, characteristic of mesothelial cells. The patient is alive and well and free of recurrence 1 year following surgery. Adenomatoid tumor is a rare neoplasm that should be added in the differential diagnosis of anterior mediastinal masses. Immunohistochemical and ultrastructural studies may be of aid in identifying the characteristic features of mesothelial cells and to avoid mistaking this lesion for more ominous conditions.

Surgical management of leiomyosarcoma of the mediastinum

Leiomyosarcoma of the mediastinum is sufficiently rare; therefore therapeutic approaches are not well defined. Current therapy primarily rests with the thoracic surgeon. We report a single case of a large leiomyosarcoma of the mediastinum invading the heart and right lung. Our diagnostic and therapeutic approach to this patient is presented and the pertinent literature is reviewed. We conclude that little advancement has been made with regard to adjuvant therapies for leiomyosarcoma of the mediastinum, and the only opportunity for cure remains with full surgical extirpation.

Sinonasal smooth muscle cell tumors: a clinicopathologic and immunohistochemical analysis of 12 cases with emphasis on the low-grade end of the spectrum

CONTEXT

Smooth muscle tumors (SMTs) of the sinonasal tracts are very rare mesenchymal neoplasms, and the literature includes very limited data correlating histologic parameters with clinical outcome. As the behavior of SMTs is site-dependent, defining applicable criteria to distinguish among low-grade leiomyosarcoma, SMT of uncertain malignant potential (SMTUMP), and cellular leiomyoma is sometimes difficult and arbitrary.

OBJECTIVE

To correlate the clinicopathologic features of 12 well-differentiated sinonasal SMTs with MIB-1 index and clinical outcomes so as to better classify this group of tumors.

DESIGN

Twelve cases of sporadic well-differentiated SMTs arising from the sinonasal tract were retrieved from both institutions. High-grade leiomyosarcomas were excluded from this analysis. The histologic parameters assessed included circumscription, mucosal ulceration, cellularity, nuclear atypia, mitotic count, necrosis, and destruction of adjacent bony structures. The histologic classification of these tumors was based on the guidelines for SMTs of deep soft tissues, using greater than 4 mitotic figures (MF)/10 high-power fields (HPF) to separate SMTUMP from leiomyosarcoma and the presence of 1 to 4 MF/10 HPF to distinguish between leiomyoma and SMTUMP. Immunostaining of MIB-1 index was performed in 7 cases with available material.

RESULTS

This study showed a 1:1.5 male-female ratio and a mean age of 40 years (range, 20-67 years). The most frequent symptoms were nasal stuffiness and/or epistaxis. The tumors involved nasal cavity in 8 cases (67%), paranasal sinus alone in 2 cases (16.5%), and both nasal cavity and paranasal sinuses in 2 cases (16.5%). The tumors ranged in size from 0.3 to 5.5 cm (mean, 2 cm) and were classified as follows: 7 leiomyomas, 2 SMTUMPs, and 3 low-grade leiomyosarcomas. All 7 leiomyomas, 1 SMTUMP, and 1 leiomyosarcoma originated from vessel walls. Bone involvement was seen in both the SMTUMPs (1 of 2) and leiomyosarcomas (2 of 3). Focal infiltrative growth was observed only in the 3 leiomyosarcomas, 1 of which also showed microscopic coagulative tumor necrosis. Mitotic figures ranged from 0 to 10 (mean, 2.3), with absence of mitosis in all 7 leiomyomas, 1 to 4 MF/10 HPF in the 2 SMTUMPs, and more than 4 MF/10 HPF in the 3 low-grade leiomyosarcomas. The MIB-1 index was low (<or=5%) in both leiomyoma and SMTUMP groups, while the leiomyosarcomas showed a higher (>or=15%) proliferative index. All 12 patients were treated by surgical excision, and only 1 patient with leiomyosarcoma received postoperative radiation. In all 12 tumors, there was neither local recurrence nor distant metastasis after an average of 93 months of follow-up (range, 4-221 months).

CONCLUSION

Well-differentiated sinonasal SMTs are rare and occur in adults with a slight female predilection. The lesions confined within the nasal cavity were more common than those involving a single paranasal sinus or both nasal cavity and paranasal sinuses. Despite variations in location, clinical manifestation, histologic features, and MIB-1 index, these tumors appear to follow a favorable course. Complete surgical excision appears to provide adequate treatment for these patients.

Primary thoracic sarcomas

Primary sarcomas of the thorax are rare. The diagnosis is established only after sarcomalike primary lung malignancies and metastatic disease have been excluded. Primary sarcomas of the thorax are classified according to their histologic features and constitute a large group of tumors that occur in the lung, mediastinum, pleura, and chest wall. Angiosarcoma, leiomyosarcoma, rhabdomyosarcoma, and mesothelioma (sarcomatoid variant) are the most common primary intrathoracic sarcomas. Ewing sarcoma, primitive neuroectodermal tumor, chondrosarcoma, malignant fibrous histiocytoma, osteosarcoma, synovial sarcoma, and fibrosarcoma usually arise in the chest wall. Although primary thoracic sarcomas commonly manifest as large, heterogeneous masses, they have a wide spectrum of radiologic manifestations, including solitary pulmonary nodules, central endobronchial tumors, and intraluminal masses within the pulmonary arteries. The different histologic types of sarcomas are frequently indistinguishable at radiologic analysis. However, differences in clinical presentation and the location of the tumor, as well as morphologic features such as calcification within the mass and rib involvement, can be useful in suggesting the appropriate diagnosis. For example, a large rib mass in a child with fever and malaise indicates a Ewing sarcoma, a mass with a calcified matrix is likely a chondrosarcoma or osteosarcoma, and a pulmonary artery mass is likely a leiomyosarcoma.

Leiomyosarcoma in the maxilla: a case report

We describe a rare case of leiomyosarcoma of the maxilla arising in a 71-year-old Japanese woman. The lesion was treated successfully by surgical resection with external irradiation of 70 Gy. No sign of recurrence or distant metastasis was present 3 years after operation. Histogenetically, this maxillary leiomyosarcoma apparently arose from the medial muscle of blood vessels or from primitive mesenchyme in the maxilla.

Smooth muscle tumor of the pleura. A case report and review of the literature

Smooth muscle tumors of the serosal membranes are extremely rare and have received little attention in the literature. To the best of our knowledge, only 1 published series of 5 pleural smooth muscle neoplasms has been published to date. We describe a primary pleural neoplasm with smooth muscle differentiation documented by light microscopy, immunohistochemistry, and electron microscopy. This tumor originated in the parietal pleura in a 32-year-old white man and was diagnosed incidentally by chest radiography; the diagnosis was confirmed by magnetic resonance imaging and biopsy. Four years later, the tumor was noted to have increased in size and disseminated into the chest wall as a separate circumscribed mass located in the pectoral muscle. Both masses were resected and diagnosed as smooth muscle tumors. We conclude that smooth muscle tumor of the pleura is a well-defined entity with a low, but definite malignant potential; therefore, we recommend complete resection and long-term follow-up for all patients.

Spindle cell thymic carcinoma: clinicopathologic and immunohistochemical study of a distinctive variant of primary thymic epithelial neoplasm

We report 16 cases of a distinctive variant of primary thymic epithelial neoplasm characterized by prominent spindling of the tumor cells. The patients were seven women and nine men aged 23 to 82 years (mean, 54 years). The lesions presented as anterior mediastinal masses without clinical or radiographic evidence of tumor elsewhere. Most patients had chest pain, dyspnea, and cough; in five patients, the tumors were asymptomatic and were discovered on routine clinical examination. Grossly, the lesions were firm, well-circumscribed, and locally infiltrative, and had a firm cut surface with foci of hemorrhage, necrosis, and cystic changes. Most of the tumors were treated by complete surgical excision. Histologically, they were characterized by a spindle cell proliferation showing varying degrees of atypia and mitotic activity. In 12 cases, transitions could be seen with areas that showed the features of conventional spindle cell thymoma. In two cases, areas showing features of poorly differentiated (lymphoepitheliomalike) carcinoma and anaplastic carcinoma could also be observed. Immunohistochemical studies in 10 cases showed strong positivity of the spindle tumor cells for CAM5.2 cytokeratin, and negative staining for a panel of antibodies including epithelial membrane antigen, carcinoembryonic antigen, actin, desmin, vimentin, S-100 protein, HMB45, CD34, CD5, and CD99. Clinical follow-up of eight patients showed an aggressive biologic behavior with recurrence, metastasis, and death by tumor in five of them 2 to 5 years after diagnosis. Based on these findings, the present tumors are interpreted as an unusual spindle cell variant of thymic carcinoma. The close association of these cases with areas showing the features of spindle cell thymoma within the same tumor mass suggests that some of these lesions may arise as a result of malignant transformation in a preexisting spindle cell thymoma.

Yolk sac tumors of the mediastinum with prominent spindle cell features: a clinicopathologic study of three cases

Three cases of primary mediastinal yolk sac tumors with prominent spindle cell features are presented. The patients were three men 24-34 years of age (mean 29). Clinically, two patients presented with symptoms of chest pain and cough; no clinical information was provided for the third patient. Grossly, the tumors were described as large mediastinal masses, with a hemorrhagic and necrotic cut surface. Histologically, the tumors were characterized by a predominantly atypical spindle cell proliferation admixed with areas that showed focally the characteristic reticular growth pattern of yolk sac tumors, with the presence of Schiller-Duval bodies and intra- and extracellular hyaline globules. Immunohistochemical studies performed in one case showed positive staining for keratin and alpha-fetoprotein in both the spindle cell and reticular components of the tumor. Follow-up information was obtained in two patients; they both died of tumor with metastases to the lungs 1 year after initial diagnosis. The present cases expand the spectrum of histopathologic growth patterns that may be observed in yolk sac tumors of the mediastinum and stress the issue of careful sampling and evaluation of mediastinal neoplasms for arriving at the correct diagnosis.

[Leiomyosarcoma of the esophagus. Clinical aspects, diagnosis and therapy based on an individual case]

Leiomyosarcomas of the esophagus are rare tumors of mesenchymal origin. Apropos of a case we present clinicopathological features, diagnostic procedures and management of this seldom tumor of the esophagus. Primary gastrointestinal sarcomas cause less than 0.5% of all esophageal malign tumors, and present in ca. 5% as esophageal leiomyosarcomas. The most frequent incidence ranges between the fourth and fifth decade of life. The tumors originate from the muscular layers of the esophageal wall and are localized predominantly in the middle and distal third of the esophagus. Dysphagia is the most important and leading symptom although it presents late in the course of the illness. Endosonography is at the time the most accurate method to establish the tumor size. Differentiation between leiomyoma and leiomyosarcoma is only possible by histopathological examination and may be difficult in certain cases. Histopathological grading of the tumors as low- and high-grade sarcomas in dependence of the number of mitosis affects predominantly the prognosis of these patients. Differential diagnosis includes spindle cell carcinoma and carcinosarcoma of the esophagus. The most effective therapy consists in the complete operative removal of the tumor, in these cases five years survival rates of 30 to 40% are achieved, strongly influenced by tumor differentiation and size.

Inflammatory leiomyosarcoma: a morphological subgroup within the heterogeneous family of so-called inflammatory malignant fibrous histiocytoma

Twelve cases of inflammatory leiomyosarcoma are presented. These tumours arose in the deep soft tissues of the trunk and proximal limbs. The age of the patients ranged from 13-53 years (median 36 years); there was an approximately equal sex ratio. Follow-up data was available for nine patients (mean duration 3.3 years); local recurrence occurred in three and lung metastases in one. Lesions were spindle cell neoplasms with fascicular areas which occupied between 5% and 80% of the tumour. Areas with a distinct storiform pattern were also seen in 10 cases. A prominent inflammatory cell component was evident in all tumours, often masking the neoplastic spindle cells. Histiocytes were identified in all cases, with aggregates of xanthoma cells seen in eight tumours. In 10 cases there was also a dense lymphoid infiltrate and in two a marked polymorphonuclear leukocyte infiltrate was evident. Immunohistochemistry showed in all tumours that the spindle cells stained positively for myogenic markers (8 of 12 positive for desmin, 10 of 12 for alpha smooth muscle actin and 11 of 12 for HHF-35). CD68 was expressed by the histiocytic infiltrates. Many of these tumours were diagnosed initially as inflammatory malignant fibrous histiocytoma. We provide evidence that at least one subset of neoplasms, which would have been formerly classified under this rubric, in fact show smooth muscle differentiation. Further studies are required to investigate the possibility that other tumour types or lines of differentiation may be present within the category of so-called inflammatory malignant fibrous histiocytoma.

Smooth muscle tumours presenting as pleural neoplasms

Five smooth muscle tumours presenting as pleural neoplasma are presented. The patients were three women and two men aged between 21 and 69 years (mean = 45 years). Clinically, one patient presented with chest pain, one with empyema and the other three were asymptomatic. Two of the tumours were located in the left side of the chest cavity and three in the right side. In four cases, the lesions presented as solitary pleural-based masses that varied in size from 10-18 cm in greatest dimension: in two of these cases, involvement of the diaphragm was present in addition to the pleural involvement. In one case, the tumour was seen to totally encase the right lung simulating the growth pattern of malignant mesothelioma. Histologically, three cases displayed an atypical spindle cell proliferation with marked cellular pleomorphism, mitoses and areas of hemorrhage and necrosis. The other two cases were characterized by a bland-appearing smooth muscle proliferation of uncertain malignant potential composed of elongated cells with a moderate amount of eosinophilic cytoplasm and cigar-shaped nuclei, lacking significant nuclear pleomorphism or mitotic activity. Immunohistochemical studies showed strong positivity for alpha-smooth muscle actin in all cases, and for desmin in four of five cases, and a focal positive reaction for keratin in one case. Ultrastructural examination in one of the high-grade tumours showed features of smooth muscle differentiation. Three of the patients were treated by complete surgical excision while, in the other two patients, the lesions were incompletely resected.(ABSTRACT TRUNCATED AT 250 WORDS)