HighlightsPRMCs are very rare and they share macroscopical and histological similarity to ovarian cystadenomas.It is important to rule out Echinococcosis specially in endemic regions such as South America.Complete surgical excision of the PRMCs is recommended to eliminate the risk of infection, recurrence and malignant degeneration.It is important to remember that cystic fluid spillage has to be prevented due to the uncertain pathology of the tumor in most of the cases.

Gastric leiomyosarcoma is a rare type of tumour that is far less prevalent than gastrointestinal stromal tumours. We describe a case of a 42-year-old male patient who consulted for upper abdominal pain. Blood work revealed low haemoglobin levels, requiring red blood cell transfusions. An esophagogastroduodenoscopy was performed, showing a submucosal tumour with central ulceration in the greater gastric curvature. The patient underwent an endoscopic ultrasound with fine needle biopsy and the sample showed a spindle cell neoplasia. Computed tomography scan demonstrated absence of distant metastases. Upon multidisciplinary consensus, it was decided to perform surgery. A laparoscopic approach was conducted, where no peritoneal lesions were observed. Transgastric resection of the tumour was performed. Free tumour margins were achieved following oncologic criteria (minimum tumour manipulation and one-piece resection without damaging the tumour capsule). After exhaustive sampling, the final pathology report informed an 11 × 9 × 5 cm gastric leiomyosarcoma. Immunohistochemical examination showed positivity with smooth muscle actin, muscle-specific actin, calponin and desmin. The patient had an uneventful recovery, and 6 post-operative months' clinical, tomographic and endoscopic control informed no disease recurrence. To the best of our knowledge, there are less than 20 published cases of patients with diagnosis of gastric leiomyosarcoma. This study highlights the importance of reporting this entity, in order to contribute to the available literature concerning this topic.

Objective Cerebral amyloid angiopathy-related inflammation (CAA-RI) is a rare and potentially treatable encephalopathy that usually affects people older than 50 years old and has an acute or subacute clinical presentation characterized by rapidly evolving cognitive decline, focal deficits and seizures. In a small subset of patients the disease can adopt a pseudotumoral form in the neuroimages that represents a very difficult diagnostic challenge. Methods Here in we report a patient with a tumour-like presentation of histopathologically confirmed CAA-RI. Results We also conducted a search and reviewed the clinical and radiological features of 41 cases of pseudotumoral CAA-RI previously reported in the literature in order to identify those characteristics that should raise diagnostic suspicions of the disease, there by avoiding unnecessary surgical treatments. ConclusionThe therapy of CAA-RI with steroids is usually effective and clinical and radiological remission can be achieved in the first month in approximately 70% of cases.

A 46-year-old man was referred to our department due to chronic chest pain. A computed tomography showed an exophytic image arising from 5th rib that was projected on the middle lobule. The patient underwent an exploratory videothoracoscopic because we couldn't discard lung compromise. A corneal-like lesion emerging from the inner side of the 5th rib was revealed. Complete video-assited resection was done. Histopathology examination revealed a desmoplastic fibroblastoma. To our knowledge this is the first case of desmoplastic fibroblastoma arising from a rib and the second case published in all literature of chest wall involvement.

A 23-year-old woman presented with symptoms of nasal obstruction of 5 years'duration, originally diagnosed as sinusitis. Clinical examination revealed bilateral polyps in the maxillary sinus, from which a biopsy was taken. This showed a tumor with a well-defined nesting (Zellballen) pattern (Figure 1), composed of large cells, some of them of giant size, with an acidophilic cytoplasm with ragged edges. The nuclei were large, and the nucleoli were very prominent ( Figure 2). Despite the high degree of cytologic atypia, mitotic activity was practically nil. The PAS (periodic acid-Schiff) stain with diastase control showed the presence, in many of the tumor cells, of a PAS-positive diastase-resistant material in the Golgi region ( Figure 3). Some of these clumps had an appearance suggestive of early crystal formation (Figure 3, arrows).The main differential diagnosis was between alveolar soft-part sarcoma, paraganglioma, and PEComa (perivascular epithelioid cell tumor). The negativity for HMB-45, Melan-A, and the neuroendocrine markers (synaptophysin, chromogranin, and neuron-specific enolase) ruled out the latter 2 alternatives. The diagnosis of alveolar soft-part sarcoma was fully supported by the strong nuclear positivity for TFE3 (transcription factor E3; Figure 4), which Figure 1. Large tumor cells with acidophilic cytoplasm forming nests Figure 2. Moderate nuclear pleomorphism in tumor cells represents the immunohistochemical expression of the chromosomal unbalanced translocation der(17)t(X;17) (p11.2;q25), which results in the ASPL-TFE3 gene fusion.The upper aerodigestive tract is a relatively common site for this rare tumor. Tumors in this location tend to occur in younger patients and to have a nesting rather than alveolar pattern of growth, which may render their recognition difficult. Surgical excision combined with chemotherapy or radiation therapy is the recommended treatment. 1-4