Susan V. Kattapuram

Accuracy of CT-guided biopsies in 359 patients with musculoskeletal lesions.

Abstract. The study was undertaken to assess the diagnostic accuracy and clinical usefulness of computed tomography (CT)-guided biopsies and fine needle aspirates of musculoskeletal lesions. The analysis compared the accuracy according to anatomical location, size, type of lesion, and histology. On the basis of the information obtained by reviewing the report of the CT biopsy and comparing it with the final diagnosis for 359 cases, the overall accuracy was determined to be 71%. The accuracy for 101 fine needle aspirations was 63% and for 258 CT-guided core biopsies was 74%. It is of note that the biopsies of 81 pelvic lesions had higher rates of diagnostic accuracy (81%) than those of 278 non-pelvic sites (68%), and especially 94 lesions of the spine (61%). The lowest success rates occurred in 26 patients with infectious diseases (50%). We conclude that these procedures remain the logical and safe choice for diagnostic studies of patients with lesions of the musculoskeletal system.

Epithelioid Hemangioma of Bone: A Tumor Often Mistaken for Low-grade Angiosarcoma or Malignant Hemangioendothelioma

Epithelioid hemangiomas are benign vascular tumors that usually occur in the skin and subcutis. They have been infrequently recognized in bone. Because of their unusual cytologic appearance and growth patterns, they are commonly confused with malignant tumors. We report a series of 12 epithelioid hemangiomas of bone occurring in adult patients, including five males and seven females whose ages at presentation ranged from 24 to 74 years, with a mean of 46 years. Five tumors were associated with involvement of the adjacent soft tissue. A single patient had multifocal bone disease. The most common presenting symptom was localized pain. Treatment of the patients varied widely; however, none of the tumors behaved aggressively. In 11 cases, adequate tissue was available for immunohistochemical analysis, which revealed positive staining for the epithelial markers cytokeratin and epithelial membrane antigen in nine cases. All 11 tumors stained for factor VIII-related antigen and Ulex europeus agglutinin. We believe that many of the vascular tumors of bone that have been reported as low-grade malignant hemangioendotheliomas probably represent examples of epithelioid hemangiomas. We recommend that the criteria for diagnosing vascular tumors of bone conform to those used for morphologically similar tumors that arise in the soft tissues

Negative scintigraphy with positive magnetic resonance imaging in bone metastases.

We report three patients with known primary tumor in whom radionuclide skeletal imaging for metastatic disease was normal with or without clinical symptomatology referable to this area. Magnetic resonance imaging (MRI) of the spine demonstrated focal areas of abnormal signal intensity in the vertebral bodies of these patients. In all three patients, biopsy confirmed metastatic disease. All the patients received radiation or chemotherapy depending upon the etiology. These preliminary data suggest that MR imaging may be useful in evaluating patients with known primary tumor in whom clinical suspicion persists despite a negative radionuclide bone scan.

Idiopathic and diabetic skeletal muscle necrosis: evaluation by magnetic resonance imaging.

ObjectiveIdiopathic and diabetic-associated muscle necrosis are similar, uncommon clinical entities requiring conservative management and minimal intervention to avoid complications and prolonged hospitalization. An early noninvasive diagnosis is therefore essential. We evaluated the magnetic resonance imaging (MRI) characteristics of muscle necrosis in 14 patients, in eight of whom the diagnoses were confirmed histologically.Design and patientsTwo experienced musculoskeletal radiologists performed retrospective evaluations of the MRI studies of 14 patients with the diagnoses of skeletal muscle infarction. In 10 cases gadolinium-enhanced (T1-weighted fat-suppressed) sequences were available along with T1-weighted, T2-weighted images and STIR sequences, while in four cases contrast-enhanced images were not available.ResultsEight patients had underlying diabetes and in six patients the cause of the myonecrosis was considered idiopathic. T1-weighted images demonstrated isointense swelling of the involved muscle, with mildly displaced fascial planes. There was effacement of the fat signal intensity within the muscle. Fat-suppressed T2-weighted images showed diffuse heterogeneous high signal intensity in the muscles suggestive of edema. Perifascial fluid collection was seen in eight cases. Subcutaneous edema was present in seven patients. Following intravenous gadolinium administration, MRI demonstrated a focal area of heterogeneously enhancing mass with peripheral enhancement. Within this focal lesion, linear dark areas were seen with serpentine enhancing streaks separating them in eight cases. In two cases, a central relatively nonenhancing mass with irregular margins and peripheral enhancement was noted. The peripheral enhancement involved a significant part of the muscle. No focal fluid collection was noted.ConclusionsWe believe that the constellation of imaging findings on T1- and T2-weighted images and post-gadolinium sequences is highly suggestive of muscle necrosis. We consider certain specific findings on gadolinium-enhanced images to be characteristic. The findings reported here should provide radiologists with useful information in making the diagnosis of skeletal muscle necrosis without resorting to invasive procedures.

Percutaneous needle biopsy of the spine

The results of 75 percutaneous needle biopsies of the spine were analyzed. There were 8 cervical, 25 thoracic, 27 lumbar, and 15 sacral biopsies. An accurate diagnosis was made in 92% of all cases. Metastatic disease yielded the best accuracy rate (96%). The lowest accuracy rate (82%) was noted with benign primary tumors and fractures. The results were better in female patients than male (97% vs. 86%). Larger needles gave slightly better accuracy (97%). No relationship between accuracy and spine level was found. There were two complications: one pneumothorax and an episode of self-limited hemorrhage. Percutaneous needle biopsy is a safe and reliable method of obtaining a diagnosis in many different spine lesions.

Epithelioid hemangioma of bone revisited: a study of 50 cases.

The clinical and pathologic features of 50 epithelioid hemangiomas of bone are analyzed. There were 29 males and 21 females who ranged in age from 10 to 75 (mean 35) years. The tumors arose in long tubular bones (40%), short tubular bones of the distal lower extremity (18%), flat bones (18%), vertebrae (16%), and small bones of the hands (8%). Nine patients (18%) had involvement of more than 1 bone. Radiographically, the lesions were lucent and well marginated. Microscopically, the neoplasms had a lobular architecture and were composed of epithelioid endothelial cells that formed obvious vascular lumina or grew in solid sheets. No hyalinized or solid appearing extracellular myxoid matrix was present. Thirty-five patients were treated with curettage, 13 patients had a local resection and 2 patients only had a biopsy. One patient had local lymph node involvement. Three patients were treated with surgery and radiation therapy. Follow-up information revealed that 4 patients experienced a local recurrence; and 1 patient developed limited involvement of a regional lymph node. Epithelioid hemangioma of bone is a benign lesion that may be multifocal and affect separate tissue and is successfully treated with curettage or marginal en bloc excision.

MR appearance of SONK-like subchondral abnormalities in the adult knee: SONK redefined

ObjectiveTo investigate the MR characteristics of SONK-like (spontaneous osteonecrosis of the knee) subchondral abnormalities in the adult atraumatic knee and to recategorize these patients into two subgroups: a subacute to chronic process associated with osteoarthritis and an acute process associated with insufficiency fractures.DesignWe retrospectively examined the knee MRIs of 39 patients with non-specific interpretations of osteochondral abnormalities.PatientsThere were a total of 52 subchondral lesions without any known traumatic event and no prior surgery. All lesions evaluated had MR features previously ascribed to SONK. Several MR characteristics were then assessed: presence or absence of a line, size, zonal location, T1 and T2 signal, associated marrow edema, associated ipsilateral meniscal tear, and associated ipsilateral cartilage defects.Results and conclusionsThe abnormalities with linear components (insufficiency fractures) tended to be larger (P<0.01) and were associated with a severe amount of marrow edema (P<0.0001) consistent with an acute process. The non-linear abnormalities were more associated with cartilage defects (P=0.01) and less marrow edema consistent with osteoarthritis and a subacute to chronic process. This association of SONK-like abnormalities with osteoarthritis and insufficiency fractures casts doubt on the validity of the term “spontaneous osteonecrosis” as it is currently applied, and further investigation into the separate etiologies of these subchondral marrow lesions is needed.

Primary myoepithelioma of bone: a report of 8 cases.

The clinical and pathologic features of 8 primary myoepitheliomas of bone were analyzed. There were 5 female and 3 male patients who ranged in age from 16 to 49 (mean, 33.5) years. Three tumors arose in the ilium, 2 in the tibia, and 1 each in the maxilla, sacrum, and L1 vertebral body. Microscopically, the tumors had a solid, lobulated, reticular, or storiform growth pattern and were predominantly composed of spindle-shaped cells arranged in intersecting fascicles with eosinophilic cytoplasm. The round to polygonal epithelioid cells were arranged randomly or formed small clusters and contained variable amounts of eosinophilic or clear cytoplasm. Immunohistochemically, all the tumors were positive for vimentin and S100 protein, and 7 were positive for epithelial membrane antigen. No tumors were positive for keratin (AE1.3/CAM5.2). Smooth muscle actin was positive in 3 tumors and negative in 4, whereas desmin was negative in all 7 tumors tested. Nuclear staining for p63 was negative in 3 tested tumors. Staining for GFAP and CD34 was performed on 4 and 5 tumors, respectively, and all showed no expression. Fluorescence in situ hybridization for EWSR1 rearrangement was performed in 7 tumors. Five tumors (71%) showed the presence of EWSR1 gene rearrangement, and 2 were negative. Cytogenetic studies conducted on 1 tumor showed 46,XY,t(1;22)(q21;q12) associated with EWSR1-PBX1 fusion. Surgical procedures included curettage in 3 patients, resection in 3 patients, and 2 patients only had an open biopsy. Follow-up information was available for 4 patients; all remain free of disease with no recurrence. Although experience with primary myoepithelioma of bone is limited, histologically, banal tumors appear to behave in a benign manner, and conservative surgery appears to be sufficient treatment. Immunohistochemical and molecular analyses are helpful in their accurate identification.

Musculoskeletal Neoplasms: Biopsy and Intervention

Percutaneous core needle biopsy and fine-needle aspiration are safe and cost-effective methods and can be important steps in the workup of a bone or soft tissue lesion. These procedures should be performed in collaboration with the orthopedic oncologist who performs the definitive surgery. In the extremities, attention to compartmental anatomy is paramount. With frozen section evaluation at the time of biopsy, the chances of a nondiagnostic specimen necessitating rebiopsy are minimized. The principles underlying the percutaneous approach to various lesions are valuable and can be applied to minimally invasive percutaneous therapy for bone and soft tissue lesions.

Musculoskeletal ultrasound: an alternative imaging modality for sports-related injuries.

Advanced technology and increasing clinical experience have established sonography as a reliable imaging modality for sports-related injuries. Tears of muscles and tendons, tendinosis, and tenosynovitis are promptly diagnosed using ultrasound. Dynamic assessment of joints can be performed, allowing diagnoses of conditions that may remain undetected when evaluated with conventional magnetic resonance imaging. Sonography provides expeditious image guidance for procedures such as drainage of fluid collections and cysts. This article reviews the applications of sonography to sports-related injuries in which its diagnostic performance may be comparable to magnetic resonance imaging.