Inwards, Carrie Y.

BackgroundAdamantinomas are rare bone tumors, commonly affecting the tibia. Due to the rare nature of disease, previous studies are small or from multiple centers. The purpose of this study is to investigate outcomes of patients with adamantinoma treated in a single institution.MethodsForty‐six histological confirmed adamantinomas of the extremities were reviewed at our institution between 1939 and 2012. Follow‐up data included clinical and radiographical information focusing on complications, local recurrence, metastasis, and overall survival after the treatment. The mean follow‐up was 16 years (range 2‐42 years).ResultsThe most common location was the tibia (n = 31). Patients commonly presented with pain and swelling. The mean age was 24 years (7‐79 years). Thirty‐seven patients were treated with limb salvage. The 39% of patients required a reoperation. The 10‐year disease specific‐ and recurrence free survival was 92% and 72%, with three patients having a recurrence over 15 years postoperative. Older (> 20 years) patients and males were at increased risk of local recurrence (P < 0.05).ConclusionTreatment of adamantinoma of the long bone consists of limb‐salvage surgery. Male patients should be cautioned on their increased risk of disease recurrence, and advocate for continued surveillance of patients even greater than 15‐years postoperatively due to late tumor recurrence.

ObjectivesTo elucidate the clinical behavior, treatment, and outcomes of tenosynovial giant cell tumors (TGCT) involving the temporomandibular joint (TMJ) and adjacent temporal bone.Study DesignRetrospective case series with histopathologic review.MethodsA retrospective chart review was performed identifying and collecting data from all cases of TGCT involving the TMJ and adjacent temporal bone that were treated at the authors' center between January 1960 and December 2015.ResultsEleven histopathologically confirmed cases met inclusion criteria. The median age at diagnosis was 49 years, eight patients were men, and the median follow‐up was 116 months. Computed tomographic (CT) imaging revealed a lytic expansile mass centered on the TMJ. Magnetic resonance imaging (MRI) most commonly exhibited hypointense signal on precontrast T1‐ and T2‐weighted sequences and variable postcontrast enhancement. The median delay in diagnosis was 24 months, and the most common presenting symptoms were hearing loss and pain. All patients underwent surgical resection, eight receiving gross total removal, one receiving near total removal, and two patients from early in the series receiving subtotal resection with neoadjuvant or adjuvant radiation. Histopathological review of surgical specimens revealed chondroid metaplasia in seven tumors. Eight of nine cases receiving gross total or near total resection have no evidence of recurrence to date.ConclusionsTGCT of the TMJ and temporal bone are rare and locally aggressive tumors that commonly present with nonspecific symptoms. A careful review of CT and MRI followed by early biopsy is critical in establishing an accurate diagnosis and facilitating appropriate treatment. TGCT of the TMJ more commonly contain chondroid metaplasia when compared to TGCT at other anatomic locations. Gross total resection is achievable in most cases and offers long‐term cure. Radiation may be considered for recurrent disease or adjuvant therapy following subtotal resection.Level of Evidence4. Laryngoscope, 127:2340–2346, 2017

By the current WHO classification, benign notochordal cell tumor (BNCT) and chordoma comprise the entire spectrum of notochordal-derived tumors. They have defined radiologic and histologic criteria, and differ considerably in management and clinical outcome. Chordomas are malignant tumors; they show progressive, destructive growth and have the capacity for metastasis. In contrast, BNCT are benign and show limited intraosseous growth. Patients with BNCT can be managed with serial imaging or conservative excision, whereas patients with spinal/sacral chordomas typically undergo radical en bloc resection often with adjuvant therapy and significant morbidity. As such, the distinction between BNCT and chordoma is critically important. We have seen 4 unusual notochordal tumors with radiologic and/or histologic features that defy classification as either BNCT or chordoma. Cases occurred in 4 adults (53 to 83 y), and involved the lumbar spine (N=2) and sacrum (N=2). Three cases had subtle radiologic features of cortical permeation with minimal soft tissue extension. All 4 cases had the characteristic histologic features of BNCT; however, 2 cases also had focal myxoid change. Three patients were followed with serial imaging (follow-up range, 26 to 120 mo); 2 showed no disease progression and 1 had a 10-year cumulative interval growth of 3.7 mm. One patient underwent sacrectomy. The tumor was examined in toto and had the characteristic histologic features of BNCT, with the exception of minimal soft tissue extension. On the basis of these observations, we propose a provisional designation of atypical notochordal cell tumors (ANCT) be used for the subset of notochordal-derived tumors that fail to fulfill current diagnostic criteria for either BNCT or chordoma. We would argue that designating these atypical notochordal tumors as chordoma precipitates potentially overly aggressive surgical management. Patients with ANCT may be better managed by close observation and serial imaging. Additional studies with more cases and longer clinical follow-up should clarify the relationship of ANCT to BNCT and chordoma.

Although the majority of giant cell tumors (GCTs) of the bone occur in adult patients, occasionally they arise in the pediatric population. In this setting they may be mistaken for tumors more commonly seen in this age group, including osteosarcoma, aneurysmal bone cyst, and chondroblastoma. All cases of primary GCT of the bone arising in patients 18 years and below were retrieved from our institutional archives and examined with emphasis on the evaluation of various morphologic patterns. Clinical/radiologic records were reviewed when available. Analysis for H3F3A/H3F3B mutations was performed in a subset of cases. Sixty-three (of 710) patients treated at our institution for GCT were 18 years of age and below. The following morphologic patterns were identified: fibrosis (31 cases, 49%), reactive-appearing bone (26, 41%), cystic change (7, 11%), foamy histiocytes (6, 10%), secondary aneurysmal bone cyst (3, 5%), and cartilage (2, 3%). Infarct-like necrosis was present in 17 tumors (27%), and the mitotic rate ranged from 0 to 35 mitoses/10 high-power fields (median 5 mitoses/10 high-power field). Follow-up information (n=55; 6 mo to 69.6 y; median, 11.6 y) showed 21 patients with local recurrence (38%) and 2 patients with lung metastasis (4%). Polymerase chain reaction with sequencing showed that 5 of 5 tested cases harbored H3F3A mutations. In summary, GCT arising in the pediatric population is rare, representing 9% of GCTs seen at our institution. The morphologic spectrum of these tumors is broad and similar to that seen in patients above 18 years of age. It is important to recognize that matrix formation may be observed in GCT, including reactive-appearing bone and cartilage, as well as areas of fibrosis mimicking osteoid production, to avoid misclassification as osteosarcoma or other giant cell–rich lesions common in children.

Pseudomyogenic hemangioendothelioma (PMH) is a well-recognized neoplasm that usually arises in the soft tissue; concurrent bone involvement occurs in 24% of cases. PMH of bone without soft tissue involvement is rare. We describe the clinicopathologic findings of 10 such cases, the largest series reported to date. The study included 9 male and 1 female patient; their ages ranged from 12 to 74 years (mean 36.7 y). All patients had multiple tumors with a distinct regional distribution: 45% restricted to the lower extremity; 25% to the spine and pelvis; and 15% to the upper extremity. On imaging studies the tumors were well circumscribed and lytic. The neoplasms were composed of spindled cells arranged in intersecting fascicles with scattered epithelioid cells; epithelioid cells predominated in 3 cases. The neoplastic cells contained abundant densely eosinophilic cytoplasm and vesicular nuclei. There was limited cytologic atypia and necrosis, few mitoses (0 to 2/10 high-power fields), and inconspicuous stroma. Unique findings included abundant intratumoral reactive woven bone and hemorrhage with numerous osteoclast-like giant cells. Immunohistochemically, most tumors were positive for keratin, ERG, and CD31; CD34 was negative. The balanced t(7:19)(q22;13) translocation was documented in 3 cases. Follow-up is limited, but no patient developed documented visceral dissemination, and all have stable or progressive osseous disease. PMH exclusively involving bone is rare. It is multicentric, often involves the lower extremity, and has unusual morphology. The differential diagnosis includes epithelioid vascular neoplasms, giant cell tumor, bone forming neoplasms, and metastatic carcinoma. Because of its rarity, unusual presentation, and morphology, accurate diagnosis can be challenging.

Context Although primary bone tumors are extremely rare, the literature suggests that there are variations in the epidemiologic characteristics in different populations. The most frequently cited epidemiologic characteristics of primary bone tumors are derived from a large US series (Mayo Clinic), with no comparable study thus far performed in China. Objective To identify any potential epidemiologic differences between Chinese patients and a US series of patients. Design We performed a comparison study between 9200 patients treated at Beijing Ji Shui Tan Hospital (JST) and 10 165 patients treated at Mayo Clinic (MC), Rochester Minnesota. Detailed epidemiologic features were analyzed. Results We found that giant cell tumor and osteosarcoma have significantly higher incidences in the JST than the MC patients (P &lt; .001). However, JST patients had a significantly lower incidence of Ewing sarcoma, chordoma, fibrosarcoma, myeloma, and malignant lymphoma (P &lt; .001). For most benign and malignant bone tumors, the Chinese cohort had a more distinct male predominance than the US cohort. Malignant bone tumors had a monomodal age distribution in the JST patient group, with a bimodal age distribution in the MC cohort. Also, there were was a predilection for tumors of the femur and tibia among the JST patients (P &lt; .001). Conclusions Our data confirm that epidemiologic variations of primary bone tumors exist in different populations. Factors that may contribute to these observed differences are proposed and discussed.