Clinico-pathological conference 2002. (1/17)
INTRODUCTION: Six cases are reported, each presented at the 11th Biennial Congress of the International Association of Oral Pathologists as an instructive case for differential diagnosis on the basis of clinical, imaging or histological features. CLINICAL PICTURE: Case diagnoses included a large, possibly intraosseous, myofibroma presenting with an oral mass; Langerhans cell histiocytosis with facial skin lesions; an intraosseous vascular hamartoma of the maxilla with worrying radiological features; an unusual mixed radiolucency of the jaw caused by cemento-ossifying fibroma; an osteosarcoma of the posterior mandible causing a well-defined radiolucency and an intraoral squamous cell carcinoma in a child. (+info)Myopericytoma: a unifying term for a spectrum of tumours that show overlapping features with myofibroma. A review of 14 cases. (2/17)
BACKGROUND: Myopericytoma (MPC) is a recently proposed term to describe a group of tumours that originate from perivascular myoid cells and show a range of histological growth patterns. Only a small number of series describing MPC have been reported. MPC is frequently misdiagnosed as a sarcoma. AIMS: To document the clinical and histopathological findings of a series of MPCs, to describe the range of growth patterns and morphological spectrum, and to compare MPC with myofibroma (MF). PATIENTS/METHODS: Fourteen patients with features of MPC and/or MF were identified from the archival files of the department of anatomical pathology, Royal Prince Alfred Hospital, Sydney, Australia. RESULTS: There were six female and eight male patients. The mean and median patient ages were 37 and 35.5 years, respectively. The tumours were located in the skin, subcutis, or superficial soft tissues of the distal extremities (13 patients) or the head and neck region (one patient), and showed a spectrum of morphological appearances. They were divided into two groups based upon the predominant growth pattern corresponding to MPC (seven cases) and MF (seven cases). The feature most suggestive of MPC was the presence of a concentric perivascular arrangement of plump spindle shaped cells. The presence of a zonation/biphasic appearance was most characteristic of MF. CONCLUSIONS: MPC exhibits a spectrum of growth patterns that overlap with MF. Tumours can be designated as MPC or MF depending on the predominant growth pattern. (+info)Utility of ALK-1 protein expression and ALK rearrangements in distinguishing inflammatory myofibroblastic tumor from malignant spindle cell lesions of the urinary bladder. (3/17)
Inflammatory myofibroblastic tumor of the urinary bladder is an unusual spindle cell neoplasm that displays cytologic atypia, infiltrative growth and mitotic activity mimicking malignant tumors, such as leiomyosarcoma, rhabdomyosarcoma and sarcomatoid carcinoma. The objective of this study was to determine if anaplastic lymphoma kinase (ALK-1) protein expression detected by immunohistochemistry and ALK rearrangements detected by fluorescence in situ hybridization (FISH) were useful in distinguishing inflammatory myofibroblastic tumor from malignant spindle cell tumors of the urinary bladder. In inflammatory myofibroblastic tumor, ALK-1 expression was identified in 13 of 21 cases (62%) and ALK rearrangements in 14 of 21 cases (67%). All cases of inflammatory myofibroblastic tumor demonstrating ALK-1 expression, carried ALK rearrangements. One case negative for ALK-1 expression exhibited ALK rearrangement. ALK rearrangements were more common in women (P=0.0032). Leiomyosarcoma, sarcomatoid carcinoma, embryonal rhabdomyosarcoma and reactive myofibroblastic proliferations were negative for ALK-1 protein and ALK rearrangements. Immunohistochemistry using markers of muscle, epithelial, neural, and follicular dendritic cell differentiation showed overlap between inflammatory myofibroblastic tumor with and without ALK gene rearrangements, and between inflammatory myofibroblastic tumor and spindle cell malignancies. However, coexpression of cytokeratin and muscle-specific antigens was unique to inflammatory myofibroblastic tumor, observed in approximately half the tumors. This study indicates that detection of ALK protein and ALK gene rearrangements are useful in distinguishing inflammatory myofibroblastic tumor from spindle cell malignancies in the urinary bladder. Additionally, our findings suggest that ALK rearrangement is the primary mechanism for ALK activation and that inflammatory myofibroblastic tumor likely represents a heterogeneous group of spindle cell proliferations with the majority associated with ALK translocations, and the remaining associated with other etiologies. (+info)Adult cutaneous myofibroma. (4/17)
A 63-year-old male presented with an asymptomatic, slow-growing swelling on the right lower limb for the past one and half years. The histopathology revealed a lobular neoplasm with a biphasic pattern of spindle shaped cells and hemangiopericytoma like areas at the periphery of the lobule. The diagnosis of adult cutaneous myofibroma was made. This case highlights the importance of histopathology in reaching a definitive diagnosis. (+info)Malignant myopericytoma-like tumor in a Fischer rat. (5/17)
(+info)Gingival myofibroma in children: report of 4 cases with immunohistochemical findings. (6/17)
Oral myofibroma is a rare tumour which usually occurs in children and has been reported in the mandible, tongue, buccal mucosa with only a few cases reported from the gingiva. It appears alarming clinically due to its fast growth which may mimic a malignancy. However, it is completely benign and is usually treated by complete surgical excision with excellent prognosis. Clinically, myofibroma presents as a single swelling when it occurs on the gingiva, and more common lesions such as fibrous epulis, pyogenic granuloma and peripheral odontogenic fibroma, myofibroma are usually considered in the differential diagnosis. We present 4 additional cases of gingival myofibroma in children. Their ages ranged from 7 to 14 years. Three were girls and 1 patient was a boy. All presented with solitary gingival growths, ranging from 3 weeks to 2 months in duration, and raised the clinical diagnoses of peripheral giant cell granuloma, pyogenic granuloma and fibrous epulis. Histopathology of incisional biopsies revealed proliferation of streaming and whorled fascicles of spindle cells around slit-like vascular spaces. The spindle cells were cytologically bland and were immunopositive for vimentin and smooth muscle actin, but were negative for desmin and S-100 protein. All were treated by surgical excision. (+info)Myofibroma of the mandible. (7/17)
This article is reporting a case of myofibroma involving the mandible of a 12-year-old boy. The patient did not have any swelling nor any redness but of partial mental nerve hypoesthesia. A panoramic radiograph demonstrated a globe like radiolucent lesion in the left angle of the mandible that was an increased uptake spot by FDG-PET. Incisional biopsies indicated myofibroma, therefore the tumor was totally resected under general anesthesia. After surgery there was no complication except for a change for the worse of unilateral mental nerve hypoesthesia. At 29 months postoperative, no evidence of recurrence could be found. (+info)Intraosseous myofibroma simulating an odontogenic lesion. (8/17)
Myofibroma is a rare benign nodular tumor of the soft tissues, bones, or internal organs, and may affect both children and adults. It is mostly found in the head and neck region, although uncommon in the jaw bones, where only a few lesions have been described. Radiographically, it may appear as a well-defined unilocular radiolucent entity simulating a cystic or odontogenic lesion. Histopathologic findings alone may be insufficient for a final diagnosis, and immunostaining for markers such as vimentin, alpha-smooth muscle actin, desmin and S-100 may be required. Intraosseous myofibroma is a diagnostic challenge and requires careful histopathologic, immunohistochemical and radiographic correlation. The present article describes a conservatively treated intraosseous myofibroma that occurred in a 7-year-old girl. The clinical, radiographic, histopathologic and immunohistochemical features are discussed. (+info)Myofibroma is a benign, often self-limiting tumor of childhood composed of myofibroblastic spindle cells arranged in a hemangiopericytoma-like pattern, which can be solitary or multiple, and may occur in various anatomic locations such as skin, subcutaneous tissue, muscle, and visceral organs.
Myofibroma is a benign, smooth muscle tumor that can occur in various parts of the body. It primarily affects infants and children, but it can also rarely be found in adults. Myofibromas are typically composed of myofibroblasts, which are cells that have features of both fibroblasts and smooth muscle cells. These tumors can be solitary or multiple and may appear as a single mass or as multiple nodules. They usually occur in the skin, soft tissues, bones, and visceral organs. Myofibromas are generally slow-growing and non-aggressive, and they often regress spontaneously over time. Treatment options include observation, surgical excision, or a combination of both, depending on the location, size, and symptoms associated with the tumor.