Mucormycosis is a rare life-threatening opportunistic infection caused by mycetes of the order Mucoraceae. It appears mainly in immunocompromised patients (hematologic malignancies, anemia, AIDS) and in cases of advanced diabetes. A delayed diagnosis may imply a worse prognosis, so an early detection is mandatory for an adequate treatment. Herein we present a rare case of multi-organ mucormycosis with pulmonary, renal, pancreatic and spleen involvement detected and assessed by 18 F-FDG PET/CT in a 24-years-old woman diagnosed of grey zone lymphoma (DLCBL/HL) who underwent an allogeneic stem cell transplantation. PET/CT with 18F-FDG was a key element in biopsy guide, final diagnosis and monitoring of response to therapy.

A case of gouty tophus in the elbow of a 62-year-old male is presented. Fineneedle aspiration (FNA) revealed the presence of acicular crystals, birefringent when viewed under polarized light as is typical for monosodium urate crystals. Histological study of the removed lesion confirmed a typical gouty tophus. We briefly comment the main characteristics of this entity.

We present morphological findings observed from the study of a myxopapillary ependymoma located in the III ventricle. This tumor, which is a rare occurrence at this level, was observed in a 73-year-old woman with no relevant medical history who presented with obstructive hydrocephalus due to compression and blockage of the foramen of Monro. The good delineation of the lesion allowed its surgical excision, and histological examination of the material obtained after excisional biopsy revealed a glial neoplasm with a low degree of cytological malignancy that was strongly positive for glial fibrillary acidic protein (GFAP) as well as a myxopapillary architecture analogous to that observed in ependymomas of the filum terminale. Subsequent radiological examination allowed us to rule out a metastatic nature of the tumor, confirming its primary origin. We briefly discuss the case and review the main characteristics of this neoplasia, which is quite rare at the site identified in our patient.

We present a mucosal Schwann cell hamartoma that was observed in a 63-year-old woman with no personal or family history of interest who underwent a screening colonoscopy for early detection of colon cancer. During colonoscopy, a small polyp with a maximum diameter of 0.8 cm was detected at the rectosigmoid level. Histologically, a benign lesion of neuroid aspect was observed, consisting of multiple spindle cell fascicles that was positive for S-100 and negative for enolase, synaptophysin, CD34, CD117, actin, desmin, Dog1, EMA, and neurofilaments. These findings, supported by the family and personal history of the patient, allowed us to make a diagnosis, discarding other entities.