Multiple oral and cerebral relapses of a Granular cell tumor (Abrikossoff Tumor) in a young girl affected by congenital dyserythropoietic anemia type II.

CASE REPORT: A 14-year-old girl presented with 1 cm large whitened lesion on the ventral surface of the tongue, appeared from 1 month. Past history showed congenital dyserythropoietic anemia type II. The lesion was excised and microscopic and immunohistochemical analyses were compatible with benign Abrikossoff tumor. Total body MRI was negative. After six months the patient presented a second tongue lesion and four months later another large painful lesion in the soft palate, with the same istological diagnosis. In addition, she had other multiple lesions: two apperead at pharyngeal level (not biopsied) that remain stable over time, and one at the pituitary gland. CONCLUSION: Granular cell tumors, with or without multiple lesions, are rare in children. About 50% of cases involve the head and neck region, with the tongue being the most affected site. Therapy is based on the surgical excision of the lesions; however some tumor forms, although their histological aspect of benignity, often have an important infiltrative power, making the therapeutic approach difficult, as in our case.

Extramedullary hematopoiesis in the facial sinus in a patient homozygous for Hemoglobin Lepore: the first case in literature.

Extramedullary hematopoiesis (EMH) is a proliferation of hematopoietic tissue outside the bone marrow. The most affected areas are paravertebral ones. We report the case of a patient with homozygous Hb Lepore, not regularly transfused since the age of four years until the age of 29 years, when paravertebral heterotopic masses were first observed. After about 10 years she started reporting clinical signs suggestive of sinusitis. Computed tomography (CT) and Magnetic Resonance Imaging (MRI) showed heterotopic masses in the ethmoid and in the frontal sinuses. Involvement of the sinuses of the large facial area represents a rare localization of EMH. Various cases have been reported in patients with thalassemia intermedia, but no case has been reported with HbLepore. The diagnostic gold standard is MRI, which provides highly accurate and clear images. The treatment is based on hydroxyurea and/or an intensive transfusional regime and sometimes on surgery.

Magnetic resonance imaging in the diagnosis of melanoma: in vivo preliminary studies with dynamic contrast-enhanced subtraction.

The aim of this study was to analyse the potential of fast dynamic subtraction magnetic resonance (MR) imaging in differentiating in vivo melanomas from benign melanocytic lesions. Dynamic MR imaging was performed after intravenous administration of gadopentetate dimeglumine (Gd-DTPA) in 18 patients with melanocytic skin lesions. Using a post-processing algorithm, time-signal intensity curves were obtained for the lesions and classified according to their shapes as type I (steady enhancement increase), type II (plateau of signal intensity) or type III (wash-out of signal intensity). Other parameters evaluated for their potential to differentiate melanomas from benign lesions were the enhancement rate (percentage of signal intensity increase) in the first minute after Gd-DTPA administration, the peak value of the enhancement rate, and the wash-out slope. The pigmented lesions were then surgically excised and the MR results compared with the histological assessment. In melanomas, the mean value of the enhancement rate in the first minute was 611%, whereas in benign lesions it was 131% (P = 0.001). The distribution of curve types was also different: seven of the nine naevi showed type I curves, while eight of the nine melanomas displayed a type III curve. In addition, distinctive wash-out dynamics were observed: the enhancement rate began to decrease between the first and third minutes for melanomas, but continued to increase until the sixth minute for naevi (P = 0.000). These findings, which are most likely related to the neoangiogenesis present in melanomas, indicate that dynamic MR imaging can be helpful in the differential diagnosis of pigmented skin lesions.

[Villous-lipomatous proliferation of synovial membrane of the knee (lipoma arborescens). Magnetic resonance findings]. / Proliferazione villo-lipomatosa della membrana sinoviale del ginocchio (lipoma arborescente). Aspetti con Risonanza Magnetica.

PURPOSE: We reviewed the imaging patterns of the villous-lipomatous proliferation of the knee synovial membrane (lipoma arborescens), with special reference to the role of MRI in the diagnosis of this rare condition. MATERIAL AND METHODS: 1994 to 1996, we examined four patients, none of them with a history of knee trauma. The clinical picture was characterized by moderate and painful suprapatellar swelling in three cases and by moderate suprapatellar swelling alone in one case. All patients were examined with conventional radiography and MRI; two were submitted to US and two to CT. The diagnosis of lipoma arborescens was suggested on the basis of imaging patterns and then confirmed by histologic findings. RESULTS: Conventional radiography showed a roughly oblong slim opacity in the suprapatellar recess in all cases; the joint space was always preserved. US showed a villous lesion surrounded by fluid, but provided no specific data on its nature. CT and MRI not only provided better location and morphologic detailing and showed the relationships with articular structures better, but also permitted the direct identification of the fat nodules within the abnormal synovial reaction. CONCLUSION: We stress the role of MRI in suggesting the correct diagnosis of lipoma arborescens, as it was subsequently confirmed in our series by histologic findings. In fact, fat-suppression sequences, after T1-weighted SE, can typify fat tissue.

["Occult" posttraumatic lesions of the knee: can magnetic resonance substitute for diagnostic arthroscopy?]. / Lesioni "occulte" post-traumatiche del ginocchio: può la Risonanza Magnetica sostituire l'artroscopia diagnostica?

PURPOSE: We investigated the actual role of MRI versus arthroscopy in the detection and characterization of occult bone and/or cartilage injuries in patients with previous musculoskeletal trauma of the knee, pain and severe functional impairment. Occult post-traumatic osteochondral injuries of the knee are trauma-related bone and/or cartilage damage missed at plain radiography. MATERIAL AND METHODS: We retrospectively selected 70 patients (men:women = 7:3; age range: 35 +/- 7 years) with a history of acute musculoskeletal trauma, negative conventional radiographs, pain and limited joint movements. All patients were submitted to conventional radiography, arthroscopy and MRI, the latter with 0.5 T units and T1-weighted SE. T2-weighted GE and FIR sequences with fat suppression. RESULTS AND DISCUSSION: We identified three types of occult post-traumatic injuries by morpho-topographic and signal intensity patterns: bone bruises (no. 25), subchondral (no. 33) and osteochondral (no. 35) injuries. Arthroscopy depicted 45 osteochondral and 19 chondral injuries. A bone bruise was defined as a typical subcortical area of signal loss, with various shapes, on T1-weighted images and of increased signal intensity on T2-weighted and FIR images. The cortical bone and articular cartilage were normal in all cases, while osteochondral injuries exhibited associated bone and cartilage damage with the same abnormal MR signal intensity. Sprain was the mechanism of injury in 52 cases, bruise in 12 and stress in 6. In 52 sprains (30 in valgus), the injury site was the lateral compartment in 92.3% of cases (100% in valgus), associated with meniscal damage in 73% of cases (90% in valgus) and with ligament injury in 90.4% (100% in valgus). In 12 bruises, the injury site was the lateral compartment in 58.3% of cases, the knee cap in 25% and the medial compartment in 16.7%; meniscal damage was associated in 25% of cases and ligament damage in 8.3%. In 6 stress injuries, the injury site was localized in the medial tibial condyle in 80% of cases, while meniscal and ligament tears were absent. CONCLUSIONS: After comparing MR with arthroscopic findings and reviewing the available literature, we conclude that arthroscopy permits the direct visualization of even fine articular surface changes but does not depict the subchondral bone, the most frequent site of injury detected with MRI. MRI was a very useful tool in the detection and characterization of the different types of occult bone and/or cartilage injuries and showed a statistically significant correlation between site and distribution of bone and cartilage injuries and between internal damage and trauma mechanisms. Therefore, we believe that MRI can help avoid diagnostic arthroscopy in the patients with a history of post-traumatic pain, acute articular blocks and negative radiographic findings.