Bone metastases from chondroblastoma: a rare pattern of metastatic disease in an adult

Chondroblastoma is a rare benign tumor, typically presenting in the first two decades. Systemic metastases in chondroblastoma are extremely rare and it is the rarity of these metastases which lead the World Health Organisation to re-classify this lesion from "intermediate" to "benign" in its updated classification of bone tumors in 2020. We present an unusual case of a 55 year-old male patient who presented with multiple FDG-avid bone lesions on a background of conventional chondroblastoma of the rib excised at another institution 11-years previously. Two of these lesions were also histologically-proven as conventional chondroblastoma at biopsy. This case highlights that, although rare, metastases can be seen in patients with chondroblastoma. To our knowledge, this is the only case with an unusual pattern of metastases limited to bone.

Chondroblastomas in Children and Young Adults: Revision of 55 Cases

BACKGROUND

Chondroblastomas are uncommon primary bone tumors localized in long bone epiphyses in children and young adults. The risk of metastasis is rare, but they have a high capacity for local recurrence. Surgical curettage with bone grafting or bone substitute is the preferred treatment.

METHODS

We performed an observational retrospective study of chondroblastomas treated in 2 hospitals in Barcelona from 1988 to 2018. We reviewed the location of the tumor, clinical presentation, imaging, histopathology, initial treatment, and cases of recurrence with a review of their treatment. We assessed the correlation between recurrence and index surgery, anatomic location, and certain histopathologic findings (presence of mitotic figures, necrosis, and positivity for protein S-100).

RESULTS

The series included 55 patients treated from 1988 to 2018, with ages ranging from 6 to 26, and a mean follow-up of 6.1 years (±3.7). The most common location was the distal femur metaphyseal/epiphyseal region. The most frequent clinical presentation was pain in the affected. Forty-five cases (81.8%) were treated with curettage of the tumor, and 4 cases (7.3%) with a wide resection. Forty-two cases (85.7%) received bone substitutes after curettage or resection. We found 5 cases of recurrence (9.1% recurrence rate); however, we could not find a statistically significant correlation between index surgery and recurrence ( P =0.24), anatomic location and recurrence ( P =0.49), or recurrence and histopathologic findings (mitotic figures, P =0.49; necrosis, P =0.60; positivity for protein S-100, P =0.52). In all the cases the treatment for the local recurrence was surgical, with a final healing rate of 100%.

CONCLUSIONS

Chondroblastomas should be considered in children and adolescents when presenting with pain and an image suggestive of a tumoral lesion on plain x-ray, most frequently in epiphyses of long bones.Surgical treatment is preferred, obtaining good results after curettage and bone substitute. Chondroblastomas are tumors with a high capacity for recurrence, therefore an adequate surgical technique and surgeon experience are paramount to achieve good outcomes.

LEVEL OF EVIDENCE

Level IV (case series). Therapeutic studies-investigating results or treatment.

Chondroid Tumors of Bone

Recent scholarship on enchondroma, chondrosarcoma, and chondroblastoma is presented. The focus of this article is on the imaging appearance of these tumors and the means by which they can be distinguished from one another by both clinical and imaging criteria.

What's New in Pediatric Orthopaedic Tumor Surgery

BACKGROUND

Pediatric Orthopaedic Oncology is a developing subspecialty within the field of Pediatric Orthopaedics. Traditionally, the field of Orthopaedic Oncology has been focused on the skeletally mature individual, and the research tends to be all encompassing rather than truly evaluating isolated populations. The purpose of this review is to summarize the most clinically relevant literature in the field of Pediatric Orthopaedic Oncology over the last 6 years.

METHODS

We evaluated the PubMed database utilizing keywords for pediatric orthopaedic oncology: sarcoma, osteosarcoma, Ewing sarcoma, bone cyst. In additionally, we further broadened our search by searching for relevant articles in the contents sections of major orthopaedic surgery journals that routinely publish both pediatric and orthopaedic oncology literature. In keeping with "What's New," we selected the most clinically relevant articles published in the last 6 years from January 1, 2014 through February 2020. Basic science and systemic therapies literature was widely reviewed and the research and clinical trials most relevant to pediatric sarcoma and neoplastic processes found in the pediatric population were included.

RESULTS

Our search yielded 60 articles that met general criteria, from which 14 were determined to be most relevant to the goals of this paper. Of the papers presented in this review, there were papers related to management of benign tumors/tumor-like conditions, bone cysts, limb salvage procedures, and amputation procedures. Ultimately included in the review were 5 studies related to limb salvage, 4 related to bone cysts, 1 related to multiple hereditary exostoses, 2 related to osteofibrous dysplasia, 1 related to chondroblastoma, and 1 discussing cementation in skeletally immature patients. They were level III, IV, and V studies. Basic science and systemic therapies literature was widely reviewed and the research and clinical trials most relevant to pediatric sarcoma and neoplastic processes found in the pediatric population were included. Our search of the basic science and systemic therapies literature yielded 19 sources were found to be pertinent to our aims and 18 of those sources were published between 2015 and 2020.

CONCLUSIONS

There are many, varied, and creative procedures in the realm of limb salvage, though there remains a lack of high-level evidence to support some of the more novel procedures. In regards to benign bone tumors, despite a more solid base of literature, there still does not seem to be consensus as to the best treatment. In particular, there continue to be many schools of thought on the treatment of benign bone cysts. Research in the basic science arena and systemic therapies are advancing in exciting ways in regards to pediatric sarcoma. Orthopaedic oncologic research specific to the pediatric population overall continues to be impeded by low sample sizes and inadequate levels of evidence, which limits the ability of surgeons to draw definitive conclusions from the literature.

Pediatric Chondroblastoma and the Need for Lung Staging at Presentation

PURPOSE

Chondroblastoma is a benign, but potentially locally aggressive, bone tumor with predilection for the epiphysis of long bones in growing children. Historically, there is a reported 2% risk of lung metastasis, however these cases are mostly in the form of isolated single reports and the vast majority in adults. The purpose of this study was to identify the "true" risk of lung metastases at presentation in skeletally immature patients with a benign chondroblastoma, and therefore revisit the need for routine chest staging.

METHODS

This was a multi-institution, international retrospective study of children and adolescents diagnosed and treated for a benign chondroblastoma. We focused on the screening and diagnosis of lung metastasis, type of staging utilized and the incidence of local recurrence. Detailed review of the available literature was also performed for comparison.

RESULTS

The final studied cohort included 130 children with an average age of 14.5 years (range: 6 to 18 y). There were 94 boys and 36 girls. Lesions more often involved the proximal humerus (32/130), proximal tibia (30/130), and proximal femur (28/130). At an average follow-up of 50 months, there were 15 local recurrences (11% rate) and no cases of lung metastasis. All patients underwent chest imaging at presentation. The overall reported lung metastases rate in the pulled literature review (larger series only) was 0.4% (7/1625), all patients were skeletally mature.

CONCLUSIONS

This is the largest cohort of pediatric-exclusive chondroblastoma in the literature. Despite minor differences in management between the centers included, the recurrence rate was similar and there was no evidence of lung metastasis (0 in 130). The incidence of distant involvement in a true benign chondroblastoma in children is much lower than the 2% previously reported in the literature, and the need for routine chest staging should be revisited.

LEVEL OF EVIDENCE

Level III.

[Giant chondroblastoma of the femur]

Chondroblastoma is a benign cartilaginous bone tumor. The large dimension and aggressive local spread of the tumor may create a diagnostic problem. A 24 x 17 x 15-cm chondroblastoma is described in a 50 year-old woman. The tumor of typical structure was located in the upper femur, growing into soft tissues and pelvic bones. Thirteen months following interilioabdominal exarticulation, the patient was found to have neither local recurrence nor distant metastases.

Calcaneal chondroblastoma with pathologic fracture and recurrence

Chondroblastomas account for <2% of all bone tumors. The calcaneus is the fifth most common location of occurrence. Males in their second decade of life are most often affected, presenting with an insidious onset of localized pain, swelling, and tenderness. The finding of associated pathologic fracture has been rare. Imaging studies can aid in the formulation of the differential diagnosis and surgical plan. The definitive diagnosis requires histologic examination. Curettage and bone grafting is curative in >80% of cases. Local recurrence rates of ≤38% have been reported, most often because of inadequate resection, and have been associated with malignant conversion and metastasis. Adjuvant therapies can help minimize the incidence of local recurrence. Long-term follow-up examinations are recommended, given the protracted interval that can exist between recurrence and the potential for malignant conversion and metastasis. We present the case of a young, healthy, active male with a calcaneal chondroblastoma and associated pathologic fracture whose initial treatment consisted of curettage, hydrogen peroxide lavage, and allogeneic bone grafting. Recurrence developed at 15 months postoperatively and was treated with repeat curettage, high-speed burring, and reconstruction with steel Steinman pins and polymethylmethacrylate, resulting in no pain or recurrence at the 5-month follow-up point.

Metachronous Bilateral Chondroblastoma of the Proximal Part of the Femur with a Pathologic Fracture: A Case Report

CASE

A twenty-two-year-old man presented with metachronous bilateral chondroblastoma of the proximal part of the femur with a pathologic fracture. The pathologic fracture on the right side was treated with tumor resection and total hip arthroplasty. Within forty-three months, the chondroblastoma in the left femoral head was detected and treated with the same protocol as the chondroblastoma on the right side. No metastatic lesion was evident at this time; because of its benign appearance histologically, the lesion was diagnosed as a metachronous lesion.

CONCLUSION

In a patient who has been previously diagnosed with and treated for chondroblastoma, skeletal pain at another site may represent a metachronous lesion.

The imaging of cartilaginous bone tumours. I. Benign lesions

Benign cartilage tumours of bone are the most common benign primary bone tumours and include osteochondroma, (en)chondroma, periosteal chondroma, chondroblastoma and chondromyxoid fibroma. These neoplasms often demonstrate typical imaging features, which in conjunction with lesion location and clinical history, often allow an accurate diagnosis. The aim of this article is to review the clinical and imaging features of benign cartilage neoplasms of bone, as well as the complications of these lesions.

Peculiar chondroblastoma involving multiple tarsal bones

A case of peculiar chondroblastoma involving multiple tarsal bones in a 49-year-old woman is described. The patient presented with pain and swelling of the right foot. Radiographs revealed a lytic expansile lesion of medial, intermediate, and lateral cuneiform bones, navicular, cuboid, and tarsal bones of the right foot, indicating a malignant tumor. Biopsies demonstrated a diffuse proliferation of round cells with eccentric and indented nuclei with longitudinal grooves and eosinophilic cytoplasm. Atypia was prominent, but mitotic figures were rare. The stroma was chondroid with focal chicken-wire calcification. On electron microscopy, the tumor exhibited chondroblastic features. The patient is alive with the tumor 7 years after radiotherapy. The tumor is considered a chondroblastoma with low malignant potential.

A case of spine origin chondroblastoma metastasis to lung

Chondroblastoma is a rare benign cartilaginous neoplasm that accounts for approximately 1% of all bone tumors and characteristically arises in the epiphysis of a long bone, particularly the humerus, tibia, and femur. Chondroblastoma can affect people of all ages. It is, however, most common in children and young adults between the ages of 10 and 20 years. Although most chondroblastomas are cured by limited surgical procedures, occasional lesions behave more aggressively and may even metastasis. In this case a young man with pulmonary metastatic chondroblastoma on spine is presented. Unlike previously published examples of metastatic chondroblastoma, these metastasis developed before any operative manipulation of the primary tumor. And primary tumor site was also unusual. The histologic characteristics of the primary, metastatic tumors were those of a conventional chondroblastoma.

Intracranial extraosseous chondroblastoma simulating meningioma

Extraosseous chondroblastoma had been reported in different parts of the body but not intracranially. We report a case of a pathologically proven intracranial extraosseous chondroblastoma of the right cavernous sinus in an 18-year-old woman with CT, MR, and conventional angiographic features simulating meningioma.

The cryosurgical treatment of chondroblastoma of bone: long-term oncologic and functional results

BACKGROUND

Chondroblastoma of bone is a rare tumor that occurs most often in the epiphysis or apophysis of long bones. This benign tumor sometimes shows aggressive or malignant behaviour, and rarely metastases occur. Since wide resection often leads to growth impairment, intra-lesional curettage followed by an adjuvant therapy is developed to decrease the negative effects on growth and function without increased recurrence rates.

PATIENTS AND METHODS

Between 1980 and 2001, 18 patients were treated for chondroblastoma of bone. Since 1989 cryosurgery has been used as an adjuvant treatment. The functional and oncologic results at follow-up were studied.

RESULTS

Four patients were treated with curettage, and four with wide resection without adjuvant therapy. One patient developed a local recurrence and distant metastases. Ten patients were treated with curettage and cryosurgery. One patient developed a local recurrence 6 years later that was treated with curettage and cryosurgery again. No serious complications from cryosurgery occurred and the functional results at follow-up were excellent [mean MSTS score at follow-up 29].

CONCLUSIONS

Chondroblastoma of bone is a benign tumor with a relatively high recurrence rate. The local recurrence rates can be decreased with cryosurgery as a local adjuvant therapy with excellent functional results.

Cortical chondroblastoma: report of a case and literature review of this lesion reported in unusual locations

Chondroblastoma is a rare benign tumor occurring in adolescence and young adulthood, almost always involving the epiphysis of long bones. A 24-year-old man presented with a discrete soft-tissue lesion penetrating the cortex of the right distal femoral metadiaphyseal region. Biopsy revealed a chondroblastoma, and the patient subsequently underwent a total curettage of the lesion with cancellous bone graft from the iliac crest.

Giant chondroblastoma of the scapula with pulmonary metastases

A 53-year-old man presented with a 12-year history of a progressively growing solid mass at his left shoulder. A 39x30x18-cm and 14.440-kg mass including the scapula was resected. Pathologic features were specific for chondroblastoma. During the 36-month follow-up, he had multiple inoperable metastatic lesions in his lungs. Histology of the transthoracic needle biopsy showed the metastatic nodules had features specific for chondroblastoma; however, the microscopic features additionally had hyperchromasia and increased mitotic activity in some areas. In the English literature, there are a few cases of chondroblastoma located in the scapula. It is exceptional to see this lesion in the sixth decade of life and with pulmonary metastases.

Treatment and prognosis of chondroblastoma

Chondroblastoma is an aggressive tumor of bone with the capacity for recurrence and metastasis. We sought to determine the prognostic factors that affect survival and local recurrence with particular emphasis on surgical technique and the anatomic constraints of the open physis. It was hypothesized that an open growth plate would impact the local recurrence rate negatively and be a primary determinant of treatment outcome. We retrospectively reviewed 82 consecutive patients treated at one institution. Intralesional treatment with meticulous curettage and bone graft resulted in local control in the majority of patients. Four local recurrences developed between 5 and 51 months. An open growth plate was not found to correlate with local recurrence. In most cases, the open physis did not considerably impact surgical technique. Although the median age of the patients was 16 years, the majority of patients had a closed or closing physis. Few patients had substantial growth remaining. A physeal-sparing operation was done in six patients, and no local recurrences were observed in this group. The factors that seemed to affect local recurrence included inadequate surgery and biologic aggressiveness of the tumor. Inadequate surgery was likely to be the cause of local recurrence in patients who presented after previous treatment elsewhere. Three patients who developed local recurrence manifested increased biologic aggressiveness of disease. These patients subsequently developed metastatic disease and malignant transformation of disease. All three patients died from their disease. Pelvic tumors tend to be biologically more aggressive and more apt to recur locally and metastasize to distant locations.

LEVEL OF EVIDENCE

Therapeutic Study, Level IV (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Metastatic chondroblastoma with elevated creatine kinase and paraneoplastic neurologic autoimmunity

A 17-year-old girl presented with chondroblastoma of the fibula and pulmonary metastases. Serum creatine kinase (CK) was elevated for a decade preoperatively and fell to near normal after tumor excision. An episode of aseptic meningitis 3 months later led to serologic detection of three antibody markers of paraneoplastic neurologic autoimmunity that in adult patients are characteristic of thymoma and lung carcinoma: muscle-type acetylcholine receptor (AChR) autoantibody (Ab), type 2 Purkinje cell cytoplasmic Ab (PCA-2), and collapsin response-mediator protein-5-IgG (CRMP-5-IgG). Locally recurrent chondroblastoma was excised 1 year later. Serum CK was elevated, CRMP-5-IgG was positive, PCA-2 was lower, and AChR Ab was undetectable. Three years after diagnosis she has stable pulmonary metastases, with elevated CK, higher PCA-2, positive CRMP-5-IgG, and undetectable AChR Ab. The association of metastatic chondroblastoma, elevated CK, and an evolving profile of paraneoplastic autoantibodies reveals a previously unrecognized immunobiologic dimension of chondroblastoma.

Chondroblastoma: varied histologic appearance, potential diagnostic pitfalls, and clinicopathologic features associated with local recurrence

Chondroblastoma is a rare, benign bone tumor. Although it has distinctive clinicopathologic features, its wide morphologic spectrum may pose diagnostic problems. We present the clinicopathologic features of 42 patients (28 males, 14 females; age range, 8 to 66 years), with emphasis on unusual histologic features, potential diagnostic pitfalls, and factors associated with recurrence. Thirty-four tumors were in long bones, with the most common site being the proximal femur. Unusual histologic features included the presence of atypical, epithelioid, spindle, and foamy cells and necrosis and a diffuse basophilic myxoid matrix. Tumors with focal osteoclast-like giant cell rich areas (n = 11), prominent cystic change (n = 8) and extensive fibromyxoid areas (n = 3) resembled giant cell tumors, aneurysmal bone cysts, and chondromyxoid fibromas, respectively. The diagnosis of referring pathologists was inaccurate in 34% of cases. Six patients (14%) had local recurrence. The only clinical feature significantly associated with increased risk of local recurrence was duration of symptoms for less than 6 months (log rank P =.003). None of the histologic features was significantly associated with recurrence. These included worrisome features such as cellular atypia, necrosis, and mitoses. None of the patients had metastases. An increased awareness of the morphologic spectrum of chondroblastomas will enable pathologists to avoid diagnostic pitfalls. We emphasize the need for a combined clinical, radiologic and histologic approach to the diagnosis of chondroblastomas.

Fine-needle aspiration cytology of chondroblastoma of soft parts: case report and differential diagnosis with other soft tissue tumors

Chondroblastoma is a benign tumor arising in the epiphysis of long bones. The extraskeletal presentation is most unusual. We report the first cytological description of a soft tissue chondroblastoma. It was a subcutaneous mass in the leg of a 62-yr-old man. Fine-needle aspiration (FNA) rendered a highly cellular material with grouped and single polygonal or round cells with a uniform, sometimes eccentric nucleus. Microvacuolated cytoplasm and hemosiderin pigment were frequent findings. There were rare nuclear grooves and mitoses. A metachromatic, focally calcified stroma was present, occasionally surrounding the cells. There were also numerous multinucleated osteoclast-like giant cells. Histological evaluation was diagnostic of chondroblastoma. The tumor was locally aggressive. A review of other soft tissue masses with similar cytological findings is included in the discussion. FNA cytology is very helpful in the diagnosis of soft tissue chondroblastoma, but additional studies may be necessary for a definitive diagnosis.

Chondroblastoma: a study of 11 cases

AIM

Chondroblastoma is an infrequent and unique neoplasm that is histologically characterized by chondroblastoma cells, osteoclast-like giant cells and sometimes reactive osteoid. Although it is generally regarded as benign, it may recur and sporadically metastasize to the lung. Many important questions concerning the prognostic factors and adequate surgical treatment of chondroblastoma have not been fully answered and remain controversial. The purpose of this study was to determine clinicopathological features useful in prediction of the tumour behaviours.

METHODS

Eleven chondroblastoma cases were reviwed clinicopathologically. According to Enneking's radiographic grading system, seven cases were classified as stage I, three cases as stage II and one case was classified as stage III.

RESULTS

Nine cases had initially been treated with simple curettage, one had aggressive curettage applied as a primary surgery and one underwent amputation. Among the nine simple curettage cases, one recurred and was reoperated with aggressive curettage. Adjuvant treatment (alcohol and/or cement) was applied in the two aggressive curettage cases; none demonstrated further tumour recurrence. All lesions were curettaged, and one case recurred. The rate of proliferating-cell nuclear antigen expression was significantly higher in the recurrent case.

CONCLUSION

The recurrent case seemed to have a high growth activity. Simple curettage was effective for local control during the initial treatment in most cases, but aggressive curettage and adjuvant treatment with alcohol and/or cement was useful for local control in recurrent chondroblastoma and chondroblastoma presenting with an aggressive behaviour.

Chondroblastoma of the talus: a case report

Chondroblastoma of bone is an uncommon condition that has a predilection for secondary ossification centers, particularly of the humerus, tibia, and femur. Treatment usually involves surgical curettage and autogenous bone graft. This article reports the case of a chondroblastoma affecting the talus of a young man and a minimally invasive surgical approach for the treatment of this lesion. The patient presented with an 18-month history of right ankle pain and swelling. The lesion involved most of the talar body, with 2.5-cm cortical erosion inferiorly at the posterior talocalcaneal facet. A lateral approach was made to the talus and a window was fashioned at the distal end of the sinus tarsi under fluoroscopic guidance to allow access to the lesion. This was curetted and the defect was filled with autogenous bone graft taken from the ipsilateral iliac crest. The patient underwent an uneventful recovery, and was asymptomatic at follow-up 24 months postsurgery. He had 75% movement at the subtalar joint, when compared with the contralateral foot.

Malignant and benign bone tumors

The authors have intentionally included some confusing examples to demonstrate that the imaging findings of benign and malignant pediatric bone lesions are not always pathognomonic. The radiologist's role is to recognize malignant bone lesions and encourage the prompt referral of these patients to an appropriate institution for biopsy and treatment. The radiologist must also be able to identify benign lesions and help determine whether these lesions require biopsy and intervention or simply observation.

Chondroblastoma-like chondroma of soft tissue: an underrecognized variant and its differential diagnosis

Soft-tissue chondromas are usually composed entirely of mature hyaline cartilage. Infrequently, however, they may exhibit morphologic features that result in diagnostic difficulty. The authors report a series of eight hypercellular soft-tissue chondromas composed of enlarged chondrocytes within a variable amount of chondroid matrix that often demonstrated delicate calcifications and contained numerous osteoclast-like multinucleated giant cells. This histologic appearance closely resembles that of chondroblastoma of bone. However, its extraosseous location, dense cellularity, and poorly formed cartilage can cause confusion with more aggressive chondroid neoplasms of soft tissue. The clinicopathologic features of these chondroblastoma-like chondromas are discussed, emphasizing the characteristics that facilitate their accurate identification.

Atypical pulmonary metastases: spectrum of radiologic findings

Typical radiologic findings of a pulmonary metastasis include multiple round variable-sized nodules and diffuse thickening of interstitium. In daily practice, however, atypical radiologic features of metastases are often encountered that make distinction of metastases from other nonmalignant pulmonary diseases difficult. A detailed knowledge of the atypical radiologic features of a pulmonary metastasis with a good understanding of the histopathologic background is essential for correct diagnosis. Squamous cell carcinoma is regarded as the most common cell type of a cavitating metastasis, but metastatic nodules from adenocarcinomas and sarcomas also cavitate occasionally. Calcification can occur in a metastatic sarcoma or adenocarcinoma, which makes differentiation from a benign granuloma or hamartoma difficult. Peritumoral hemorrhage results in areas of nodular attenuation surrounded by a halo of ground-glass opacity. Pneumothorax commonly occurs in metastases from an osteosarcoma. Air-space consolidation is often seen in cases of metastases from gastrointestinal tract malignancies. Even though tumor emboli in pulmonary arteries can be seen at computed tomography, diagnosis is difficult because they are located in small or medium arteries. A common radiologic appearance of an endobronchial metastasis is an atelectasis. In cases of an endobronchial or a solitary pulmonary metastasis, differentiation between bronchogenic carcinoma and metastasis is difficult. Dilated vascular structures within the mass can be seen in metastatic sarcomas. A sterilized metastasis after chemotherapy is radiologically indistinguishable from a residual viable tumor. Benign tumors such as uterine leiomyomas and giant cell tumors of the bone rarely metastasize to the lung.

Pulmonary sclerosing hemangioma consistently expresses thyroid transcription factor-1 (TTF-1): a new clue to its histogenesis

The histogenesis of pulmonary sclerosing hemangioma has remained controversial despite extensive studies by many investigators. The availability of an antibody to thyroid transcription factor-1 (TTF-1), which is expressed in type II pneumocytes and Clara cells, has prompted us to readdress this issue. Sixteen cases were immunostained with a panel of antibodies including TTF-1. The patients were predominantly women with an age range of 30 to 73 years (mean, 52 yrs). All tumors were solitary. The single male patient showed regional lymph node metastases, an unusual occurrence reported only once in the literature. All cases exhibited the classic histologic features, with variegated patterns. TTF-1 expression was observed in both the surface lining cells and the pale polygonal cells. The surface lining cells were epithelial membrane antigen (EMA)+ cytokeratin+ surfactant apoprotein A+, whereas the polygonal cells were EMA+ cytokeratin- surfactant apoprotein A-. The neuroendocrine markers synaptophysin and chromogranin were both negative. The metastatic deposits in the lymph nodes comprised only polygonal cells and exhibited an EMA+ cytokeratin- surfactant apoprotein A- TTF- 1+ immunophenotype. These results suggest that pulmonary sclerosing hemangioma is an epithelial neoplasm derived from primitive respiratory epithelium or incompletely differentiated type II pneumocyte or Clara cell.

Fibro-osseous, osseous, and cartilaginous lesions of the orbit and paraorbital region. Correlative clinicopathologic and radiographic features, including the diagnostic role of CT and MR imaging

Fibro-osseous and cartilaginous lesions of the orbit and facial region share overlapping clinical, radiologic, and pathologic features that may lead to diagnostic confusion and possible misdiagnosis. The value of imaging studies in the histopathologic diagnosis of these lesions cannot be overemphasized. The histopathologic diagnosis of such lesions should not be rendered in the absence of radiographic correlation.