OBJECTIVE: To investigate and describe clinical, radiologic and pathologic findings of gastrointestinal stromal tumors. MATERIALS AND METHODS: In the period between December 2000 and March 2006, 16 patients were submitted to surgery for gastrointestinal stromal tumors in our institution. The following variables were taken into consideration: sex and age, signs and symptoms at presentation, tumor site and size, radiological and pathological features, and presence of metastasis. RESULTS: The study population was constituted by nine men and seven women. The primary tumor sites of origin were: stomach (n = 5), rectum (n = 4), small bowel (n = 3), mesentery (n = 3), and colon (n = 1). Mean primary tumor size was 9 cm. Computed tomography was the main radiological method utilized. Circumscribed, lobulated and heterogeneously contrast-enhanced mass was the main image finding. Metastasis was found in nine patients (56% of cases) at presentation or tumor recurrence was observed during the follow-up period (mean = 32 months). CONCLUSION: Gastrointestinal stromal tumor occurs in middle-age adults and the elderly, and must be taken into consideration as differential diagnosis for abdominal masses. Early diagnosis, adequate therapy, and rigorous follow-up are essential, considering the high probability of malignancy of these neoplasms as demonstrated by the present study.

Keywords: Gastrointestinal stromal tumor, Gastrointestinal neoplasms, Gastrointestinal diseases, Sarcoma

OBJECTIVE: To describe the different presentations of craniofacial fibrous dysplasia in a revisional study of 14 computed tomography exams. MATERIALS AND METHODS: The authors have selected 14 cases of craniofacial fibrous dysplasia attended at the Head & Neck Surgery/Otorhinolaryngology Service and Diagnostic Imaging Service of "Hospital Heliópolis", São Paulo, SP, Brazil, between 1991 and 2002. Three of the following most relevant tomographic findings were analyzed: number of bones affected, predominant radiological presentation and the disease uni- or bilaterality. RESULTS: A predominance of a mixed pattern was observed in relation to the disease presentation. Also, contiguous involvement of two or more bones was observed as well as equivalence between cases of unilateral and bilateral craniofacial involvement, possibly due the fact that most patients presented the monostotic type of fibrous dysplasia. CONCLUSION: The knowledge of tomographic features of craniofacial fibrous dysplasia is of paramount importance for surgical planning and post-treatment follow-up.

Keywords: Fibrous dysplasia of bone, Skull, Face, Facial bones, X-ray computed tomography

OBJECTIVE: To present the experience of Santa Cecília Hospital (São Paulo, SP, Brazil) radiology service in the handling of computed tomography-guided fine-needle aspiration biopsy and percutaneous core biopsy of pulmonary lesions, analyzing their importance and associated complications. MATERIALS AND METHODS: One hundred and sixty-eight computed tomography-guided biopsies were performed in 84 men and 84 women. Sixty-four patients underwent fine-needle aspiration biopsy, 68 underwent percutaneous core biopsy and 36 patients underwent both techniques. RESULTS: Pneumothorax occurred in 38 patients, and pulmonary hemorrhage in then cases. The biopsied lesions ranged in size from 0.5 to 15 cm. The diagnosis was achieved at the first attempt in 132 cases and at the second attempt in ten cases. CONCLUSION: The accuracy of fine-needle aspiration and percutaneous core biopsies depends both on the size of the lesion and the patient's cooperation. These techniques are relatively safe and present a high diagnostic accuracy when performed by an experienced professional.

Keywords: Biopsy, Cancer, Computed tomography

We report a case of a patient with actinomycosis of the larynx mimicking a neoplasm. A literature review, clinical features, pathology and imaging findings is also presented. This paper reports a rare disease occurring in an atypical location, simulating larynx neoplasm. To our knowledge, there is no report of this disease and locations evaluated with computed tomography.

Keywords: Actinomycosis, Computed tomography, Cancer

The aim of this study is to evaluate the sinonasal complex to identify the main findings and to determine the diseases in this area. An accurate analysis of the local extent and tumoral dissemination through computed tomography and magnetic resonance imaging plays a significant role in the therapeutic planning, also affecting the prognosis.

Keywords: Nasal sinuses, Computed tomography, Magnetic resonance imaging

OBJECTIVE: To evaluate the role, especially of computed tomography, in the staging of maxillary sinus carcinomas. MATERIALS AND METHODS: Ten cases of carcinoma treated in Hospital Heliópolis Department of Diagnostic Imaging and Head and Neck Surgery, São Paulo, SP, Brazil, in the period between 1988 and 2002, were evaluated. RESULTS: Nine patients presented with tumor extension to the cheek, eight to the masticator space, seven to the mouth floor and hard palate, five to the pterygoid fossa, five to the orbit, three to the ethmoid bone, and one to the skull base. Three of the patients were staged T3, and seven T4. Two patients had lymph nodes metastases at their initial presentation, and were staged T4. All of the cases were histopathologically confirmed. CONCLUSION: The accurate analysis of the tumor local extent and dissemination by means of computed tomography and magnetic resonance imaging plays a relevant role in the surgical planning, besides influencing the therapeutic conduct and prognosis.

Keywords: Squamous cell carcinoma, X-ray tomography, Cancer, Maxillary sinus

OBJECTIVE: To evaluate the role of computed tomography in the assessment of deep extension of squamous cell carcinoma of the external auditory canal. MATERIALS AND METHODS: In the period between May 1995 and December 2003 six patients with squamous cell carcinoma of the external auditory canal were submitted to computed tomography scan at "Hospital Heliópolis", São Paulo, SP, Brazil, including axial and coronal slices with soft tissue and bone algorithms. RESULTS: Thickening of the soft tissue of the external auditory canal was seen in all patients, bone erosion and invasion of the middle ear in five (83.3%), invasion of the mastoid and parotid gland in four (66.7%), invasion of the temporomandibular joint in three (50%), and invasion of the middle cranial fossa, carotid canal and cervical lymph node enlargement in two (33.3%) patients. CONCLUSION: Assessment of deep extension of squamous cell carcinoma of the external auditory canal using computed tomography is useful for clinical staging of the disease allowing better therapeutic planning for these patients.

Keywords: Squamous cell carcinoma, External auditory canal, Computed tomography

The aim of this study is to report a rare case of hepatic artery aneurysm simulating a lesion in the head of the pancreas. A precise evaluation using computed tomography and magnetic resonance imaging is important in the treatment planning, which will influence the prognosis.

Keywords: Hepatic artery, Aneurysm, Pancreas, Computed tomography, Magnetic resonance imaging