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 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

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

OBJECTIVE: The aim of this study is to evaluate the role of computed tomography and magnetic resonance imaging in the characterization of deep tissue extension of malignant tumors of the nasal cavity. MATERIALS AND METHODS: Twelve patients diagnosed with malignant tumors of the nasal cavity were retrospectively evaluated at the Departments of Diagnostic Imaging and Head and Neck Surgery of the "Complexo Hospitalar Heliópolis", São Paulo, Brazil, between 1990 and 2000. All cases were confirmed by histopathologic examination. RESULTS: Extension to the maxillary and ethmoid sinuses was identified in six patients, extension to contralateral nasal cavity, orbit and lamina cribosa in five patients, extension to nasal pharynx and masticator space in two patients, extension to cavernous sinus, anterior/middle cranial fossa, pterygomaxillary fossa, inferior/superior orbital fissure, frontal sinus, contralateral ethmoid sinus, contralateral lamina cribosa, hard palate and pterygopalatine fossa in one patient. CONCLUSION: It is important to precisely assess the local extension and spread of tumor by computed tomography and magnetic resonance imaging in order to plan the approach to treatment, which will influence the prognosis.

Keywords: Nasal cavity, Malignant neoplasm, Computed tomography, Magnetic resonance imaging