Cerebellar T-cell lymphoma: an unusual primary intracranial neoplasm

Summary Primary T-cell lymphoma within the central nervous system is extremely rare. Imaging characteristics appear indistinguishable from the more common B-cell lymphoma. A case of such a primary tumor is discussed and the MRI and CT findings presented.     

Spinal metastasis from occult intracranial germinoma mimicking primary intramedullary tumour

We report a patient who initially presented with an intramedullary spinal tumour and developed an intracranial germinoma 3.5 years later. The original spinal tumour was thought to be a metastasis from the germinoma, occult at that time.     

Migrated herniated disc mimicking a neoplasm

Disc sequestration is defined as migration of a herniated disc fragment into the epidural space such that it is completely separated from the parent disc. We report a case of a migrated herniated disc that was initially pathologically diagnosed as a cartilage neoplasm. In addition to confounding morphological features, this interpretation may have been influenced by an initial radiological interpretation that did not include herniated disc in the differential diagnosis of a spinal lesion with prominent peripheral contrast enhancement. MR imaging is most helpful in considering other lesions in the differential diagnosis including abscess, hematoma, and primary or metastatic neoplasms. Pathologically, degenerative changes in herniated discs, including clustering of chondrocytes and neovascularization, may be severe resulting in a pseudoneoplastic appearance. Increased awareness of the radiological and pathological features of migrated herniated disc should limit confusion with other tumors.     

Duodenal diverticulum mimicking a cystic pancreatic neoplasm

Duodenal diverticula occur very commonly, with a prevalence as high as 22%. They are most frequently located in the second or third portions of the duodenum, and by nature of their proximity to the head of the pancreas, can be mistaken for cystic pancreatic neoplasms by diagnostic imaging. Patients with presumed cystic neoplasms of the pancreas often receive pancreaticoduodenectomies, which at high volume medical centres carry mortality and morbidity rates of 2-4% and 29-44%, respectively. Although most duodenal diverticula are recognized in single or repeat CT scans by the presence of air or contrast medium within the diverticula, we present a case in which serial CTs failed to yield any clue to the diverticulum's true nature and pancreaticoduodenectomy was performed. For presumed cystic lesions adjacent to the duodenum, barium studies, endoscopy, and/or endoscopic ultrasound-guided aspiration should therefore be pursued in addition to all available CT evidence prior to surgery.     

Adenomyoma mimicking an aggressive uterine neoplasm on MRI

This case report concerns a nulliparous female with prolonged vaginal bleeding, where MRI demonstrated a mass with an aggressive, tumour like appearance involving the posterior aspect of the uterus. Histological examination confirmed that this was an adenomyoma. The unusual imaging appearance of this lesion and its differential diagnosis are discussed. Adenomyoma should be considered in the differential diagnosis of aggressive-appearing uterine masses.     

Spinal dural AV fistula mimicking a vertebral neoplasm

A middle-aged man with spinal dural arteriovenous fistula mimicking a vertebral neoplasm of Th11 is described. CT and MR imaging revealed the rare case of extensive vertebral destruction of Th11.     

Crohn's disease angiographically mimicking vascular malformation or neoplasm

We report a young woman with lower gastrointestinal bleeding in whom, angiographically and surgically, the offending cecal lesion appeared to be a vascular malformation or neoplasm. Pathologically, Crohn's disease associated with extremely prominent vascularity was discovered to be responsible for this unusual appearance and the bleeding.     

Mesenteric venous collateral vessels mimicking cystic pancreatic neoplasm

We report an unusual case of intrapancreatic mesenteric venous collateral vessels following partial pancreatic surgical resection resembling pancreatic neoplasm upon greyscale sonographic and unenhanced CT examinations.Cystic lesions of the pancreas can be divided into three broad categories: lesions without an epithelial lining (pseudocyst), lesions with an epithelial lining (mucinous and serous cystadenoma and cystadenocarcinoma) and degenerative or necrotic change within a solid neoplasm (solid pseudopapillary neoplasm and cystic degeneration of ductal adenocarcinoma or neuroendocrine tumour). Here we report an unusual aetiology for a cyst-like pancreatic lesion: intrapancreatic mesenteric venous collateral vessels developing after a previous partial pancreatic resection. Failure to recognise this condition, particularly during image-guided intervention such as biopsy, endoscopic retrograde cholangiopancreatography (ERCP) or during surgery, could result in a disastrous outcome.     

Olfactory neuroblastoma visualized by Technetium-99m-ECD SPECT.

We describe a case of olfactory neuroblastoma diagnosed by 99mTc-ECD SPECT. Although MRI and CT are very important for delineating these tumors, they are, by no means, specific for neuroblastomas. 131I-MIBG scintigraphy, the standard method for imaging tumors of neural crest origin, also failed to detect a histologically proven esthesioneuroblastoma.     

Solitary rectal ulcer syndrome mimicking rectal neoplasm on MRI

Solitary rectal ulcer syndrome (SRUS) is a rare condition that typically affects young adults and describes a spectrum of clinicopathological abnormalities. The diagnosis of SRUS is usually made on the basis of a combination of presenting symptoms and endoscopic and histological appearances. Characteristic radiological appearances have been described on transrectal and endoanal ultrasound, defecating proctography and barium enema. The radiological appearance of solitary rectal ulcer on MRI has not been previously described. MRI appearance of thickened ulcerated mucosa in the anterior rectal wall are non-specific and was indistinguishable from a malignant process. However, given that solitary rectal ulcer has a pre-disposition to occur in the anterior rectal wall, the presence on MRI of thickened rectal mucosa in this location could suggest solitary rectal ulcer in the correct clinical context.     

Cysticercosis mimicking brain neoplasm: MR and CT appearance

The clinical and radiologic manifestation of neurocysticercosis are varied. Since the introduction of anticysticercal drugs, surgery is only rarely needed in treatment. During the last 2 years, we have encountered two patients with minimal symptomatology whose cerebral CT and magnetic resonance studies demonstrated single lesions consisting of an enhancing nodule surrounded by edema. There was ring enhancement of the nodule in one case and homogeneous enhancement in the other. Surgery was performed in both cases, because the primary consideration was brain tumor.     

Intestinal neoplasm mimicking a Meckel's diverticulum on scintigraphic imaging.

A 33-year-old man presented with colicky, intermittent, midabdominal pain with nausea and vomiting. A Tc-99m pertechnetate abdominal scan was performed and revealed a focal area of increased uptake in the midabdomen associated with dilated proximal loops of small bowel. Surgery revealed a high-grade partial obstruction of the midportion of the jejunum secondary to an annular adenocarcinoma of the jejunum. This is the first known report of abnormal Tc-99m pertechnetate accumulation in an adenocarcinoma of the small bowel.     

神经母细胞瘤酷似畸胎瘤声像图表现一例

患儿男,一岁四个月。入院前两周发现右腹部局限性隆起。入院查体:右上腹部可触及13cm×10cm的肿物,质硬、无囊性感、光滑、活动度差,压之无哭闹。超声检查示:右上腹部可探及105×81mm的混合性包块,边界尚清,形态不规则,内部回声以中低回声为主,并可见强回声光团,后方伴声影,与肝脏分界清楚,右肾受压并可见中度积水。超声提示:腹部混合性包块,考虑为畸胎瘤。CT示:右侧腹腔肝门处可见不规则软组织影,密度不均匀,其内可见高密度灶,CT值173.4Hu,中心亦有低密度区,右肾盏呈球形扩张,腹膜后淋巴结肿大,肿块与周围组织及大血管分界不清。CT诊断:…     

Apophysitis of the ischial tuberosity mimicking a neoplasm on magnetic resonance imaging

We present multimodality imaging features of an ischial tuberosity apophysitis in a 13-year-old boy who was an active baseball pitcher. Roentgenography of the pelvis and computed tomography showed mild irregularity in the inferior margin of the left ischial tuberosity. T1-weighted MRI showed a wide area with low signal intensity in the left ischial body; T2-weighted fat-suppression images showed areas with markedly high signal intensity in the ischial apophysis and body and the surrounding periosteum; contrast-enhanced T1-weighted fat-suppression MRI showed that the ischial body, surrounding periosteum, and origin of the hamstring muscles strongly enhanced; technetium-99m scintigraphic scans showed increased isotope uptake in the entire ischial body. Histological specimens obtained from the bone showed increased osteoblastic activity, edema, and proliferation of benign spindle cells and small vessels in the bone marrow spaces. In the present case, because MR imaging demonstrated extensive signal abnormalities involving the apophysis, periosteum, and intramedullary portion of bone, a neoplasm could not be excluded, and a biopsy was undertaken.