Bd Nguyen

Gastrointestinal: Small bowel and mesenteric primary myeloid sarcoma: PET/CT imaging.

Figure 1 (a) Axial, sagittal, and coronal computed tomography (CT) images showing a 4-cm enhancing soft tissue mesenteric mass (arrows) with adjacent mesenteric adenopathy and circumferential wall thickening (arrowheads) of the proximal-mid ileum. (b) Post bowel resection positron emission tomography/CT images in the axial, sagittal, and coronal projections showing the 18F-FDG-avid midline mesenteric mass (standardized uptake value (SUV) 13.1) and adjacent mesenteric adenopathy (SUV 3–3.5).

Gastrointestinal: Gastrointestinal involvement of mantle cell lymphoma

A 58 year-old Caucasian man, with a history of hyperlipidemia and benign prostate hypertrophy, complained of 3-week rectal bleeding. He also had a 6-month history of left lower quadrant pain, diarrhea, unintentional 14-pound weight loss, and urticaria. Examination revealed no lymphadenopathy, palpable mass, or organomegaly. Abnormal laboratory results were as follows: gamma globulin 1.7 (normal: 0.6–1.6 g/dL), immunoglobulin A 439 (50–400 mg/dL). Other studies included white blood cell, hemoglobin, albumin, lactate dehydrogenase, uric acid, beta-2 microglobulin, C-reactive protein, C1 esterase inhibitor, and other immunoglobulins were within normal limits. Computed topographic (CT) colonography (Figure 1, left) and colonoscopy (Figure 1, right) demonstrated innumerable sessile polyps (2–4 mm) throughout the entire colon. Esophagogastroduodenoscopy and video capsule endoscopy also revealed multiple small nodules in the duodenal bulb and ileum, respectively. Immunohistochemical staining of excised colonic polyps was positive for Cyclin D1 (Figure 2, 200x). The chest and abdomen CT scans showed no hepatosplenomegaly or lymphadenopathy, and the bone marrow examination was normal. The patient decided to return to his native state for further treatment. Mantle cell lymphoma (MCL) is a subtype of the B-cell nonHodgkin lymphomas (NHL) and comprises about 7% of adult NHL. MCL is characterized by the chromosomal translocation t(11:14), resulting in overexpression of Cyclin D1. Cyclin D1 is a nuclear protein that promotes cell proliferation. Positive immunohistochemical staining for this protein is diagnostic for MCL. Approximately 25% of patients with MCL present with extranodal disease. Extranodal sites include bone marrow (>60%), liver and spleen (45–60%), Waldeyer’s ring, and gastrointestinal tract (20%). Multiple lymphomatous polyposis (MLP) is a rare primary gastrointestinal (GI) manifestation of MCL. It occurs predominately in male (65%) with mean age of 63 years. Endoscopy shows small polyps (0.5–2 cm) along one or more segments of the GI tract. Common symptoms are weight loss, abdominal pain, diarrhea, and hematochezia. Clinical presentation of chronic urticaria in our patient is atypical. MLP is the least common type of primary GI lymphomas. Differentiating MLP from follicular and mucosaassociated lymphoid tissue (MALT) lymphomas is crucial because MLP has one of the poorest prognoses (median survival of 8–20 months) of all NHL subtypes and there is no accepted therapeutic approach.

EDUCATION AND IMAGING. Gastrointestinal: Positron emission tomography/computed tomography imaging of peritoneal carcinomatosis secondary to prostate adenocarcinoma.

A 62-year-old male had a history of radical prostatectomy for Gleason 4+3 prostate adenocarcinoma with extra-prostatic extension and lymphovascular invasion. Two years after the initial surgery, the patient complained of sensations of abdominal stretching and pinching with recurrent urinary tract infections. Contemporary computed tomography (CT) and positron emission tomography (PET)/CT depicted confluent hypermetabolic lesions lining the peritoneum (Fig. 1). Subsequent whole body bone scintigraphy and colonoscopy were negative for any additional osseous or colonic lesions. He underwent an open surgical biopsy of his peritoneal lesions. Histopathological analysis, by a panel of expert pathologists, reached the diagnosis of metastatic prostatic adenocarcinoma based on the staining profile and ruled out the likelihood of metastatic spread from a de novo primary malignancy such lung cancer, melanoma, neuroendocrine

Gastrointestinal: Rectal cancer initial PET/CT staging with isolated synchronous adrenal metastasis

An 88-year-old man, with a remote past history of prostate cancer treated with trans-urethral prostatectomy and external beam radiation therapy, had a recent onset of rectal bleeding. A colonoscopy found a rectal mass starting at 8 cm from the anal verge and measuring 4 cm long. Subsequent biopsy showed a moderately differentiated adenocarcinoma. Computed tomography (CT) exams reported the rectal lesion (figure 1, left axial image, arrow) without any obvious loco-regional or distant metastasis. The left adrenal gland appeared unremarkable on CT even retrospectively (Figure 1, right coronal image, circle). Pre-operative positron emission tomography (PET) confirmed the hypermetabolic rectal malignancy (Figure 2, coronal and sagittal MIP, maximum intensity projection, images, arrows). In addition PET showed abnormal fluorine-18 fluorodeoxyglucose (F-18 FDG) uptake at the left adrenal gland highly suspicious for distant metastasis (Figure 2, circles). CT-guided biopsy established the diagnosis of metastasis from rectal cancer. The patient underwent combined rectal surgery and left adrenalectomy. Adjunct chemotherapy was also planned for the stage IV of the patient’s rectal cancer. Rectal cancer rarely presents with isolated synchronous metastasis to the adrenal gland on initial diagnosis. The adrenal involvement is usually encountered at distance of the rectal surgery during the post-operative monitoring course with frequent multiorgan dissemination. Positron emission tomography/ computed tomography (PET/CT) is established as a combined functional and anatomic imaging modality for post-therapeutic surveillance of recurrent or metastatic rectal cancer based on the avidity of malignant tumor cells to incorporate and retain F-18 FDG, an analogue of glucose, for their active metabolism. PET/CT offers a more accurate colorectal cancer staging than the one provided by conventional cross-sectional imaging and consequently leads to a more appropriate therapy for patients. In the case illustrated above, PET/CT imaging upstaged the rectal cancer with the demonstration of hypermetabolic synchronous left adrenal gland metastasis, which was not conspicuous on multiple preoperative CT exams.

Gastrointestinal: Caval tumor thrombus and duodenal metastasis from endometrial carcinoma

A woman had a history of endometrial carcinoma treated with hysterectomy, bilateral salpingo-oophorectomy, and pelvic nodal dissection. After 3 years of uneventful postoperative course, the patient complained of a right lower back pain irradiating to the right inguinal region and right proximal lower extremity. Radiographs and magnetic resonance imaging of the lumbar spine and pelvis were negative for osseous lesions. However, the magnetic resonance exam depicted, on the limited field of view of the lumbar spine imaging, a possible right retroperitoneal lesion compressing the inferior vena cava. Subsequent F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (CT) and contrast-enhanced CT of the abdomen and pelvis showed a bilobed hypermetabolic mass. The anterior and horizontal component of the mass represented the duodenal involvement, and the posterior and vertical component corresponded to the inferior vena cava invasion with tumor thrombus (Fig. 1). Endoscopic biopsy of the duodenal lesion showed histological evidence of metastasis from the initially resected endometrial carcinoma (Fig. 2). The patient underwent surgical resection of the duodenal and caval metastasis with, unfortunately, short survival outcome due to subsequent widespread tumor dissemination. Endometrial carcinoma, the most common gynecologic malignancy, typically metastasizes locally and into para-aortic and pelvic lymph nodes before disseminating hematogenously throughout the body. Gastrointestinal tract metastasis from gynecologic malignancies, of rare occurrence, mostly originates from melanoma, breast, lung, colon, and renal cell carcinomas. The exact incidence of small bowel metastasis of gynecologic origin is currently unknown due to its rarity and asymptomatic presentation until the advanced stage of the disease. Caval tumor thrombus is also an uncommon complication in patients with gynecologic malignancies. This case highlights the diagnostic value of F-18 FDG positron emission tomography/CT, contrast-enhanced CT, and endoscopic ultrasound in the detection of atypical metastasis from endometrial carcinoma.

Gastrointestinal: Recurrent urothelial cancer of the remnant ureter invading the ileal conduit: PET/CT imaging

A 68-year-old man complained of hematuria for three months. His past history was remarkable for urinary bladder cancer treated initially with cystectomy and ileal conduit urinary diversion, and nephroureterectomy 5 years later from high-grade urothelial carcinoma of the right renal pelvis and right ureter. For the present hematuria 6 years after the right nephroureterectomy, 18 F FDG PET/CT demonstrated a hypermetabolic lesion of the right ureteral stump with involvement of the uretero-ileal anastomosis and ileal conduit (Fig. 1). Contemporary CT showed a 2.9 × 5.8 × 2.3 cm tubular mass in the lower right retroperitoneum extending as a filling defect into the ileal conduit. PET/CT and CT exams were consistent with a recurrent urothelial carcinoma confirmed by tissue sampling (Figs 1, 2a). The patient received 2 cycles of carboplatin and gemcitabine neoadjuvant therapy with a favorable response as evidenced by a significant reduction of the ureteroileal lesion (Fig. 2b). Subsequent radiotherapy was planned. Standard practice for patients with bladder urothelial carcinoma with invasion into the muscularis propria is cystectomy. There are many surgical approaches to urinary diversion. One of the most common is the ileal conduit, a procedure in which a 15-cm portion of the ileum is diverted, thus creating a reservoir for urine. The ureters are then anastamosed to the proximal end of this conduit. Patients with cystectomy have a local tumor recurrence rate of 3–16%. One longitudinal study found the tumor re-occurrence rate involving the upper tract to be 4% at 3 years and 7% at 5 years after cystectomy. In another multicentric retrospective study patients with ileal urinary diversion were found to have a secondary tumor rate involving the ileal conduit of .02%. The study also suggested that ileal conduit diversion has a lower rate of cancer recurrence than colonic diversion methods of urinary diversion. Unlike many other post-cystectomy diversion methods, where the secondary tumor recurrence is often gastrointestinal in origin, ileal conduits were found to be almost exclusively urothelial in origin. Additionally, most of the recurrences occurred at the site of uretero-ileal anastomosis. PET/CT is usually limited for the evaluation of urinary malignancy involving the urinary tract because of presence of physiologic 18 F FDG urine activity interfering with the detection of any potential tracer-avid lesion. The use of forced diuresis with furosemide and delayed PET/CT imaging may be effective, in certain instances, in un-masking underlying hypermetabolic urothelial diseases. In our case, the remnant right ureteral stump, free of any urine, offers an excellent target-to-background activity ratio for the FDG-avid tumor with extension to the uretero-ileal anastomosis and ileal conduit. These PET features correspond to the tumor filling defects seen on contemporary CT.

Hepatobiliary and Pancreatic: Hepatic necrobiotic xanthogranuloma

A 52-year-old woman consulted our institution for an established diagnosis of IgG kappa monoclonal gammopathy of undetermined significance with coexisting facial and lower extremity cutaneous eruptions. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (CT) staging showed heterogeneous hepatic tracer uptake most dominant at the right lobe with no obvious hypermetabolic osseous lesion (Fig. 1a–c). CT and magnetic resonance exams confirmed the presence of nonspecific diffuse infiltrative hepatic lesions (Fig. 1d,e). Subsequent hepatic and cutaneous biopsy reached the diagnosis of necrobiotic xanthogranuloma (NXG). The patient was treated with lenalidomide and dexamethasone with mid-term mixed results: partial hepatic lesion improvement and occurrence of marked lower extremity cutaneous ulceration from worsening of NXG vasculopathy (Fig. 1f). Necrobiotic xanthogranuloma is a chronic soft tissue inflammation with potentially disfiguring and ulcerating cutaneous features mostly involving the peri-orbital regions, head and neck, torso and extremities. It is frequently associated with different stages of multiple myeloma and lymphoproliferative disorders such as chronic lymphocytic leukemia and Hodgkin’s and non-Hodgkin’s lymphoma. NXG occurrence in other organ systems, namely, central nervous system, heart, lung, and liver, is possible but less frequent. Hepatic involvement is rare with only a few reported cases in the medical literature and scarce imaging details. NXG pathogenesis is not totally elucidated but probably represents macrophage lipid homeostasis impairment secondary to the hematologic and lymphoproliferative disorders mentioned earlier. Our case showed on positron emission tomography/CT the diffuse hypermetabolic pattern of NXG inflammatory and granulomatous hepatic F-18 FDG uptake and on CT and magnetic resonance the corresponding nonspecific disseminated nodular/miliary lesions reminiscent of infiltrative disorders such as metastasis, lymphoma, or amyloidosis. NXG diagnosis is histologic with dense sheet of granulomatous inflammation with focal areas of palisaded necrobiosis/necrosis, foamy histiocytes, lymphocytes, foreign body giant cells, and Touton cells. Therapy relies on an array of immunomodulatory drugs, proteasome inhibitors, immunosuppressive agents, alkylating agents, corticosteroids, and high-dose chemotherapy with mixed results.

Gastrointestinal: Cystic endosalpingiosis of the spleen: CT, MR, and US imaging

A 49-year-old woman had, during the clinical evaluation of acute hepatitis, incidental findings of multiloculated splenic cystic lesions on CT, MR, and US (Fig. 1a–c). The clustered splenic cysts are complex, with some of them exhibiting rim of calcification, suspicious for echinococcal cysts. Even though the patient had a negative IgE antibody Western block test for Echinococcus, she had high-risk factors of echinococcal exposure based on her occupation and travelling habits. Given the complexity of these exophytic cysts and the risk of spontaneous rupture in the peritoneum, splenectomy was recommended. Preoperative imaging studies of the remainder of the body showing no extrasplenic involvement. The resected spleen showed benign multiloculated, partially calcified splenic parenchymal cysts (Fig. 1d), with simple glandular epithelial structures and flat and ciliated Mullerian epithelium lining. The histologic features are consistent with cystic endosalpingiosis. With immunohistochemical stains, the lining epithelium expressed estrogen receptor, progesterone receptor, calretinin, cytokeratin 7, and WT-1. Splenic parenchyma and splenic hilar lymph nodes external to the cysts are without diagnostic abnormalities. Endosalpingiosis is the occurrence of ectopic fallopian tube-like epithelium frequently involving the ovaries but potentially targeting other soft tissue structures/linings of the abdomen and pelvis. Its pathogenesis may be from metaplasia of pluripotential coelomic epithelium into fallopian tube-like epithelium, or proliferation, shedding and seeding of tubal epithelium. Endosalpingiosis accounts for 40% of cases in postmenopausal women and coexists with endometriosis in 34.5% of cases. It may be the precursor of serous tumors and has a probable association with ovarian serous tumors. Endosalpingiosis, usually asymptomatic at early stages of the disease, is detected incidentally during the evaluation of other gastrointestinal disorders. It can induce chronic abdominal pain and tissue adhesion. At macroscopic stages with tumor-like features, it may simulate cystic malignant or parasitic processes in the abdomen and pelvis. The occurrence of splenic cystic endosalpingiosis is very uncommon.

Hepatobiliary and Pancreatic: Post-transplant recurrence of fibrolamellar hepatocellular carcinoma in lung and pancreas

A 46-year-old man had a history of multiple surgical resections of fibrolamellar hepatocellular carcinoma (FHCC), ending up with a living donor liver transplantation. Imaging monitoring detected a small left lower pulmonary nodule 12 years after the hepatic transplantation presumably from infection and especially TB due to a positive quantitative mycobacterium tuberculosis interferon result. Subsequent positron emission tomography/computed tomography (PET/CT) imaging showed the F-18 fluorodeoxyglucose-avid left lung lesion with an additional hypermetabolic tumor at the tail of the pancreas (Fig. 1a,b). CT confirmed the heterogeneously contrast-enhancing masses of the left lung base and tail of the pancreas (Fig. 1c,d). Tissue sampling along with lung resection and combined distal pancreatectomy-splenectomy established the diagnosis of bi-focal FHCC recurrence (Fig. 2). Fibrolamellar hepatocellular carcinoma is a rare indolent and presumably less aggressive variant of HCC, accounting for less

Gastroenterology: Small bowel intussusception from metastatic melanoma with retained video capsule

A 55 year-old woman, with a history of malignant scalp melanoma and extranodal involvement in 2005, was treated with resection, complete neck dissection, radiation, and 1 year of GM-CSF regimen. She recently experienced a progressively worsening gastrointestinal symptomatology with nausea, epigastric pain, abdominal distention and 8-lbs weight loss. Clinical work-up found a hemoglobin level of 4.8 g/dl suspicious for microscopic gastrointestinal bleed without any overt hematemesis or melena. Colonoscopy and esophagogastroduodenoscopy were negative. Capsule endoscopy was marked by the retention of the video capsule in the small bowel loops. Subsequent CT enterography demonstrated a 3.2 cm contrast-enhancing mass within the small bowel acting as a lead point for intussusception with a nearby retained video capsule (Fig. 1, CT, top row, and PET/CT, bottom row, intussusception, arrows, retained video capsule, circles). This represented a new finding compared to a prior CT performed a year ago, although upon review, there appeared to be an overlooked subtle contrast-enhancing small bowel lesion (Fig. 1, left upper corner, arrow). Based on the working diagnosis of primary or secondary malignancy, the ensuing whole body PET/CT demonstrated a 3.3 × 4.7 × 4.3 cm hypermetabolic mass in the small bowel confirming the intussusception with impacted capsule (Fig. 1). Surgical resection revealed a 5-cm pedunculated polypoid mass obstructing the lumen of the small bowel resulting in the capsule retention (Fig. 2). Immunohistochemical studies on the tumor cells were positive for S-100 and MART-1 and negative for HMB 45, pancytokeratin, chromogranin, CD117, and CD45, consistent with metastasis from the patient’s initial scalp melanoma. Capsule endoscopy is a useful imaging technique for the evaluation of occult gastrointestinal bleed. The retention of video capsule is a rare procedural complication secondary mostly to NSAID enteropathy and to lesser extent small bowel tumors. The majority of the cases with capsule retention are asymptomatic, although there is a potential risk of acute small bowel obstruction or perforation. The combined finding of intussusception, uncommon in adults compared to the pediatric patient population, and capsule retention should raise a high suspicion for gastrointestinal primary or secondary malignancy, particularly in patients with prior history of malignant melanoma as seen in this case.