Painful histiocytoma in dogs images forearm mass

A 40-year-old woman presented with a painful mass on her forearm. She denied injury to the area or prior surgery at histiocytoma in dogs images the site. She reported no additional lesions and stated that the mass histiocytoma in dogs images arose over the past few weeks and has become painful histiocytoma in dogs images to the touch. Physical examination revealed a non-compressible non-mobile nodular mass. There was no overlying skin discoloration or ulceration. Radiographs, ultrasound and MR images of the lesion were obtained. MR images are displayed (fig.) key clinical finding(s)

A soft tissue mass is a relatively frequent presenting symptom histiocytoma in dogs images with etiologies that range from the benign to the aggressive. Evaluation begins with a clinical history and physical examination, followed by imaging when the etiology is not readily apparent. Certain lesions such as lipomas have characteristic imaging features based histiocytoma in dogs images upon which confident classification can be made by MRI. However, most lesions are not easily distinguished from one another and histiocytoma in dogs images biopsy is necessary to exclude malignancy. The clinical features such as pain or redness, as well as patient demographics may narrow the differential diagnosis. Nodular fasciitis

Nodular fasciitis is a benign soft tissue lesion that is histiocytoma in dogs images primarily inflammatory in nature and is likely the most common histiocytoma in dogs images tumor-like lesion misdiagnosed as a sarcoma. 1 histological examination reveals evidence of rapid growth and increased histiocytoma in dogs images mitotic activity. The upper extremity is the most common site of involvement, along with the head and neck in younger patients. 2 the presentation of a painful forearm mass in a histiocytoma in dogs images relatively young patient makes nodular fasciitis a leading consideration in histiocytoma in dogs images this case.

Radiographs are typically noncontributory (as in this case) and additional imaging is necessary for characterization. Ultrasound is also nonspecific with the common appearance being that histiocytoma in dogs images of a hypoechoic mass. Hyperemia may also be encountered as evidence of inflammation (obtained in the workup of this mass but not shown). MRI typically demonstrates a nodular mass that is isointense to histiocytoma in dogs images muscle on T1-weighted images and hyperintense on T2-weighted images. Avid or peripheral enhancement is common. The presence of a linear fascial tail may be an histiocytoma in dogs images important distinguishing feature in identifying the lesion and is well histiocytoma in dogs images demonstrated in this case. 1 biopsy or excision is necessary to exclude a malignant histiocytoma in dogs images lesion and lesions rarely recur. 3 recurrence should prompt a reevaluation of the lesion to histiocytoma in dogs images confirm the diagnosis. 1 unlike radical excision approaches that are appropriate for sarcomas, a wide margin is not necessary and adjacent structures such histiocytoma in dogs images as nerves may be spared. 4 malignant fibrous histiocytoma

MFH is the most common soft tissue sarcoma of advanced histiocytoma in dogs images age, though lesions have been described in younger patients as well. An important fact to consider is that the majority are histiocytoma in dogs images deep lesions with only 5-10% being described in the subcutaneous tissue. 6 whenever an aggressive-appearing soft tissue mass is encountered, the diagnosis of MFH must be considered. Imaging features are nonspecific with variable appearances described on all histiocytoma in dogs images MRI imaging sequences. The presence of a spontaneous hematoma may further confuse the histiocytoma in dogs images imaging workup and in such cases it is critical to histiocytoma in dogs images identify any solid nodular enhancing components of the tumor. Fibromatosis

Fibromatoses arise from fascia or aponeuroses and are typically slow histiocytoma in dogs images growing nodular lesions. Several common sites of involvement are well described in the histiocytoma in dogs images literature and include the plantar and palmar regions of the histiocytoma in dogs images extremities. Both superficial and deep types have been described. Fibromatoses demonstrate intermediate to low signal intensity on all MR histiocytoma in dogs images imaging sequences. Chronic lesions demonstrate more collagen content and this characteristic likely histiocytoma in dogs images accounts for the low signal intensity on MR imaging sequences. Regions of the lesion that are more cellular demonstrate relatively histiocytoma in dogs images increased signal intensity on fluid sensitive sequences and are sites histiocytoma in dogs images of probable recurrence after attempted resection. Surgical resection is the primary treatment; however, recurrence is common. Following lesions closely with MRI before resection may demonstrate maturation histiocytoma in dogs images of the fibromatosis (as evidenced by more collagenous regions with low signal intensity histiocytoma in dogs images on MRI) and thus help to direct surgical intervention when the lesion histiocytoma in dogs images is less cellular and less likely to recur. 7 diagnosis

Soft tissue masses are relatively common with a confident diagnosis histiocytoma in dogs images possible in cases of lipoma and in a few select histiocytoma in dogs images other lesions. Frequently however, benign and malignant lesions overlap in terms of presentation and histiocytoma in dogs images imaging appearance. In such cases, biopsy and/or excision are necessary to exclude the presence of an histiocytoma in dogs images aggressive lesion or malignant tumor. Knowledge of the more commonly encountered lesions is necessary to histiocytoma in dogs images help guide treatment. In this case, the rapid onset of a painful nodule suggests a reactive histiocytoma in dogs images or inflammatory lesion rather than a typically slow-growing fibromatosis or malignant fibrous histiocytoma. The age of the patient and location are also important histiocytoma in dogs images clues to the ultimate diagnosis. Finally, the fascial tail demonstrated in this case helps to narrow histiocytoma in dogs images the differential diagnosis as well. Excision confirmed the diagnosis and no further treatment was required. References

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