Dedifferentiated adamantinoma associated with fibrous dysplasia

Recurrent Adamantinoma With Fibrous Dysplasia-like Feature

Adamantinoma (AD) is a rare, slow-growing primary malignant bone tumor characterized by a biphasic morphology of clusters of epithelial cells and spindle cell osteofibrous components. A strong relationship between AD and osteofibrous dysplasia (OFD) has been proposed, while fibrous dysplasia (FD) has been rarely associated with AD. We present an AD case that was followed and histologically evaluated 3 times over 6 years with different morphological patterns. The tumor in the primary biopsy and after complete resection showed classical features of AD and osteofibrous-like pattern, while the recurrent lesion presented with exclusively spindle cell morphology and was thus diagnosed as FD. However, the extensive immunohistochemical analysis in all 3 lesions revealed strong reactivity for pancytokeratin, vimentin, p63, and podoplanin, which are characteristic for AD. Although, in the FD-like section of the tumor from the first recurrence the positivity of podoplanin was stronger than pancitokeratin, which was variably positive on spindle cells. The present case highlights the problem of diagnosing AD based on a single biopsy with one tumor's component predominating over the other, and at the same time emphasizes the importance of using immunohistochemical staining for keratin and podoplanin when the histopathological features of (osteo)fibrous lesion can be linked to AD.

Adamantinoma : The first report from Syria

Adamantinoma is rare, representing less than 1 % of all primary bone tumors. It is a slow growing low grade tumor which is often clinically, radiologically and histologically mistaken for many other tumors. In this report, we present a case of Adamantinoma in a 17-year-old Syrian adolescent. The patient presented with pain and swelling anterior aspect of his left leg for last six months. We analyzed the clinical, radiographical and pathological characteristics of our patient, which helped us to reach the final diagnosis. The aim of this report is to document the presence of Adamantinoma in Syria to help other Syrian physicians considering this disease in the differential diagnosis if they face similar presentations.

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Adamantinoma is rare, representing less than 1% of all primary bone tumors.

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The first case report is attributed to Maier in the year 1900. In 1913, Fisher reported the first tibia adamantinoma.

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To our knowledge this tumor has not previously been reported in Syria.

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The aim of this report is to document the presence of Adamantinoma in Syria.

Osteofibrous dysplasia-like adamantinoma versus osteofibrous dysplasia in children: A case report of challenging diagnosis

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Challenging diagnostic regarding diagnosis of Osteofibrous dysplasia and Osteofibrous dysplasia-like adamantinoma.

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There is controversy spectrum disease between adamantinoma and OFD-like adamantinoma and OFD in children.

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Histopathology and immunohistochemical staining for diagnostic OFD, OFD-like adamantinoma and adamantinoma.

Introduction

Osteofibrous dysplasia (OFD) and Osteofibrous dysplasia-like Adamantinoma have a similar appearance both in clinical and radiography, but different in its histopathology. Despite this similarity, the treatment and prognosis are different, therefore the diagnosis should be established precisely.

Case illustration

A three-year-old boy was admitted to hospital after falling on his lower leg. A bead size lump appeared on his tibia with pain and swelling, which later became enlarged. Diagnosis of osteofibrous dysplasia and adamantinoma was considered. We performed limb-salvage procedure by curretage, bone grafting, and internal fixation application. The histology section showed woven bone rimmed by polygonal osteoblast cell with intervening fibrous stroma and small nests of tumour cells raised the possibility of epithelial differentiation. The positivity for cytokeratin immunostaining confirmed the diagnosis as osteofibrous dysplasia-like adamantinoma. In this case it is a very rare spectrum of malignancy in children.

Discussion

These two tumor entities have identical radiographic characteristics, histopathology features the distinction between classic adamantinoma and OFD-like adamantinoma based on the predominant epithelial component. The relationship of osteofibrous dysplasia with adamantinoma is unclear. Several authors considered possible calling relationship osteofibrous dysplasia as “juvenile adamantinoma”. However, does not rule out the possible existence of de novo osteofibrous dysplasia not related to adamantinoma.

Conclusions

OFD-like adamantinoma and Osteofibrous Dysplasia had similar histopathology pattern, a pathologist must be aware of this feature and perform immunohistochemical staining for keratin particularly when the histopathological feature of osteofibrous dysplasia showed small nests of tumor cells within the fibrous stroma. diagnostic challenging and require multidisciplinary approach.

Outcome of osteofibrous dysplasia-like versus classic adamantinoma of long bones: a single-institution experience

Background

The clinical and molecular characteristics of osteofibrous dysplasia (OFD)-like adamantinoma (AD) differ from those of classic AD. Most reports about OFD-like AD are case reports or small case series. More cases from different centers are still warranted.

Methods

The orthopedic oncology database of our institution was searched to identify patients with AD. The cases of OFD-like and classic AD of the long bones were retrospectively analyzed. Between December 1999 and August 2016, 23 patients were treated for AD, comprising seven with OFD-like AD and 16 with classic AD. The outcomes were compared between AD subtypes.

Results

In the OFD-like AD group, four lesions were treated with extensive curettage, while three were treated with wide resection. The median follow-up duration in the OFD-like AD group was 66 months (range 43–131 months). At the end of follow-up, there was only one case of local recurrence (LR) in the OFD-like AD group, giving a LR rate of 14.3% (1/7). No distant metastasis or progression to classic AD was detected in the OFD-like AD group. In the classic AD group, the treatments were below-the-knee amputation in one patient with extensive tibial and fibular lesions, curettage with a bone graft in one patient who was diagnosed with OFD based on a core needle biopsy, hemi-cortical excision and reconstruction in two patients, and segmental resection and reconstruction in 12 patients. At the end of follow-up, there were three cases of LR in the classic AD group, giving a LR rate of 18.8% (3/16); two patients developed lung metastasis after LR and died of the disease at 88 and 126 months after the first surgery in our hospital, respectively. The classic AD group had a metastatic rate of 12.5% (2/16), a final limb salvage rate of 75%, and estimated 5- and 10-year survival rates of 88.9% and 77.1%, respectively.

Conclusions

OFD-like AD has a better outcome than classic AD. For OFD-like AD, extensive curettage is suggested if the tumor extent allows. For classic AD, aggressive resection with wide margins is essential to achieve local control. A long-term follow-up is necessary due to the possibility of late complications.

Genetic and molecular reappraisal of spindle cell adamantinoma of bone reveals a small subset of misclassified intraosseous synovial sarcoma

Adamantinoma represents a distinct group of bone tumors showing both mesenchymal and epithelial differentiation most commonly involving the tibial diaphysis. Most adamantinomas contain a fibro-osseous component and an epithelial component consisting of squamous or basaloid cells. Adamantinomas are considered malignant neoplasms requiring en bloc excision that frequently recur locally and can rarely metastasize. Rare adamantinomas show an epithelial component consisting predominantly of monomorphic spindle cells, which, combined with an epithelial immunophenotype, can mimic monophasic synovial sarcoma. Synovial sarcoma is very rare in bone. It is considered a high-grade sarcoma that typically necessitates chemotherapy. However, the relationship between spindle cell adamantinoma and intraosseous synovial sarcoma has not been investigated. The current study was prompted by identification of a presumed spindle cell adamantinoma of the tibia with diffuse keratin expression that harbored a SS18 gene region rearrangement. FISH of eight additional bone tumors initially classified as spindle cell adamantinoma based on clinicoradiopathologic findings revealed one additional case with SS18 rearrangement. Histologically, both intraosseous synovial sarcoma and spindle cell adamantinoma demonstrated uniform fusiform nuclei with scant cytoplasm, short fascicles and low mitotic activity. The adamantinomas, but not the synovial sarcomas, were more likely to show overt epithelial differentiation in the form of pseudoglands or squamous nests. Immunohistochemistry of all cases, irrespective of SS18 status, showed diffuse keratin positivity in the spindle cell component, and less consistent EMA positivity. Clinical follow-up was available in both intraosseous synovial sarcomas, one of which recurred and the other metastasized. Two of the six spindle cell adamantinomas with follow-up metastasized. The above findings highlight the morphologic and immunophenotypic overlap between spindle cell adamantinoma and intraosseous synovial sarcoma of the tibia. Investigation of SS18 status to exclude synovial sarcoma is suggested prior to rendering a diagnosis of spindle cell adamantinoma.

High-grade squamous cell carcinoma arising in a tibial adamantinoma

Adamantinoma of the long bones is a rare, typically low-grade malignant tumor that frequently involves the tibia. Radiographically, adamantinoma is characteristically a lytic, intracortical, and expansile lesion with variable margins. Histologically, adamantinoma is a bimorphic neoplasm, composed of epithelial and osteofibrous elements. Herein, we describe a 72-year-old man with a long-standing tibial mass that, on imaging, rapidly developed cortical destruction with soft tissue extension. Imaging revealed no evidence of a distant site of origin. Needle core biopsy demonstrated high-grade squamous cell carcinoma, and metastasis was initially favored. However, the combined clinicoradiologic and pathologic features were most compatible with a high-grade squamous cell carcinoma arising in adamantinoma. The diagnosis was confirmed in the resection specimen. Both the age at presentation and histologic features make this case unusual and highlight a potential for misdiagnosis in the evaluation of squamous cell carcinoma-containing lesions of the tibia, reinforcing the importance of clinicoradiologic correlation in bone pathology.

Clinicopathologic Features of Two Rare Cases of Dedifferentiated Adamantinomas, Including Diagnostic Implications

A dedifferentiated adamantinoma is a rare subtype of an adamantinoma, associated with a relatively aggressive clinical course, with less than 10 such cases reported so far. A 25-year-old-male presented with pain in his right leg of 1-year duration. Imaging disclosed a well-defined lytic, destructive lesion in his proximal tibia with a cortical break and a soft tissue component. Microscopic examination of the biopsy and resected specimen showed nests and clusters of atypical epithelial cells, along with significant areas showing markedly pleomorphic and spindly sarcomatous cells with interspersed mitotic figures and areas of stromal hyalinization. By immunohistochemistry, the areas of epithelial differentiation showed intense positivity for cytokeratin and p63, whereas the sarcomatous areas showed reduced to absent immunostaining. A 51-year-old lady presented with a recurrent tumor in her right tibia, which was initially diagnosed as an adamantinoma, along with metastatic lesions in her lung. Microscopic examination of the recurrent and metastatic tumors showed areas of epithelial differentiation along with spindly sarcomatous cells, arranged in fascicles. By immunohistochemistry, the areas of epithelial differentiation showed positivity for pan cytokeratin. Additionally, p63 was diffusely positive. p53 showed diffuse and intense staining pattern in the sarcomatous component (dedifferentiation). While the first case is disease-free, the second case is on follow-up. The 2 cases of dedifferentiated adamantinoma further confirm the rare occurrence of this tumor in our population. Its correct diagnosis has treatment implications. Differential diagnoses and literature review of similar reported cases are also presented in this article.

Long-term outcome following treatment of Adamantinoma and Osteofibrous dysplasia of long bones

INTRODUCTION

Adamantinoma (AD) is an ultimately rare, low-grade malignant bone tumor. In most cases it occurs in the tibia of young adults. Osteofibrous dysplasia (OFD) is a rare, benign, lesion that is typically seen in children. Histopathology, ultrastructure, and cytogenetics indicate that these lesions are closely related. Yet, etiology remains a matter of debate. Local recurrence rates are high for both entities as published in literature and long-term outcomes are scarce, due to the rarity of the disease.

HYPOTHESIS

AD should be treated by En-Bloc resection while ODF can be treated by curettage or by observation. Consequently, the aim of the present study was to answer following questions: Were local recurrence rates of both entities different based on a retrospective review within a tertiary referral center for orthopedic oncology?

MATERIAL AND METHODS

In a retrospective cohort study, 10 patients with AD and 5 patients with OFD (including 1 patient with OFD-like-AD) were reviewed. Primary surgeries for patients with AD were: En-bloc resection in 7, curettage in 2 and amputation in 1. In the OFD group, only 2 patients underwent surgery by curettage. Mean follow-up was 16 years (range: 2-47 years). Nine patients had a minimum follow-up of 10 years (mean: 23 years; range: 10-47 years).

RESULTS

Four patients with AD (40%) and 2 patients with OFD (40%) - all of them following surgical removal - suffered from local recurrence. In the "En bloc" resection group of AD, there were 2 LR (29%). All patients of both groups treated with curettage showed LR. One patient with AD had metastasis at time of diagnosis and died of disease. Another patient with AD was diagnosed with metastasis 67 months after surgery and was still alive with disease at latest follow-up (77 month).

DISCUSSION

The overall prognosis of AD and OFD is good, yet local recurrence rates are high, irrespective of surgical strategy. While an internationally standardized treatment regime is still missing, a more radical surgical approach should be considered, especially when treating AD.

LEVEL OF EVIDENCE

Retrospective study; Level IV.

Clinicopathological features of five unusual cases of intraosseous myoepithelial carcinomas, mimicking conventional primary bone tumours, including EWSR1 rearrangement in one case

Primary intraosseous myoepithelial tumours, including carcinomas are rare tumours. The concept of histopathological spectrum of these tumours is evolving. We describe clinicopathological and immunohistochemical features of five myoepithelial carcinomas, including molecular cytogenetic results in one case. There were five male patients within age-range of 8-40 years (median = 26). Four tumours occurred in the long bones, including two tumours, each, in the femur and fibula, respectively, while a single tumour occurred in the proximal phalanges. Tumour size (n = 3 cases) varied from 5.6 to 8.6 cm. On radiological imaging, most tumours appeared as expansile, lytic and destructive lesions. Two tumours appeared as sclerotic lesions. Two cases were referred with diagnoses of chondrosarcomas and a single case was referred with two different diagnoses, including an adamantinoma and an osteosarcoma. Histopathological examination in all these cases showed multinodular tumours comprising mostly polygonal cells, exhibiting moderate nuclear atypia and interspersed mitotic figures within a stroma containing variable amount of myxoid, chondroid, hyalinised and osteoid-like material. Three tumours revealed prominent squamous differentiation. By immunohistochemistry, tumour cells were positive for EMA (5/5), pan CK (AE1/AE3) (3/3), CK5/6 (4/4), CK MNF116 (1/1), S100 protein (5/5) and GFAP (3/5). The first tumour revealed EWSR1 rearrangement. The first patient, 10 months after tumour resection and a simultaneous lung metastatectomy, is free-of-disease (FOD). The second patient, 11 months after tumour resection is FOD. The third and fourth patients underwent wide resections and are on follow-up. The fifth patient underwent resections, including a lung metastatectomy. Primary intraosseous myoepithelial carcinomas are rare and mimic conventional primary bone tumours. Some primary intraosseous myoepithelial carcinomas display EWSR1 rearrangement. Squamous differentiation may be considered as an addition to their evolving histopathological spectrum. Immunohistochemical stains constitute as a necessary tool for arriving at the correct diagnosis in such cases, which has treatment implications. Surgical resection remains the treatment mainstay.

Multiple recurrences and late metastasis of adamantinoma in the tibia: a case report

Adamantinoma is a rare, low-grade, malignant bone tumour. We report on a 46-year-old woman who had early multiple recurrences of adamantinoma of the right tibia and late metastasis to the lung and ribs 13 years after the first surgical treatment. She underwent multiple complete tumour excisions and eventually below-knee amputation and removal of the left lung and sixth to eighth ribs.

Sarcomatous transformation (Leiomyosarcoma) in polyostotic fibrous dysplagia

Malignant changes in polyostotic fibrous dysplasia are very rare. Most common malignancies reported are osteosarcoma and fibrosarcoma, chondrosarcoma and malignant fibrous histiocytoma. Here, we report a previously diagnosed case of fibrous dysplasia who has developed leiomyosarcoma; diagnosis of which was delayed for about one year despite repeated fine needle aspiration and open biopsy.