Littoral cell angioma of the spleen diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy.

Littoral cell angiomas are uncommon primary vascular neoplasms that arise from the sinusoidal lining or littoral cells of the splenic red pulp, and hence are unique to the spleen. We report a case of littoral cell angioma in 34-year-old woman, which was diagnosed by endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNAB). The cytologic features of littoral cell angiomas have been described only in three previous case reports, one of which was a bench-top aspirate. In our case, we have utilized the fine-needle aspiration samples obtained by a linear endoscopic ultrasound examination for establishing the diagnosis. The characteristic cytologic features identified on the smears along with immunohistochemical analysis performed on the compact cellblock prepared from the aspirate aided in the confirmation of the diagnosis. We suggest that EUS-FNAB is a safe and reliable method in the diagnosis of vascular lesions of the spleen.

Complications associated with the serological evaluation of febrile transfusion reactions.

The evaluation of a transfusion reaction is a complex process aimed at detecting acute intravascularhemolysis through clinicalinvestigation and serologic assays. However, several variables can complicate testing in the postreaction period and obscure an accurate diagnosis. We report a patient with myelodysplasia who was noted to have a febrile response to a unit of red blood cells (RBCs). Testing of the posttransfusion specimen raised concerns for a hemolytic transfusion reaction when the patient's RBCs demonstrated a positive direct antiglobulin test (DAT) and the plasma showed incompatibility with the donor RBCs. Further evaluation revealed that: (1) antibiotic treatment induced a "false" positive DAT in the patient, and (2) donor RBCs were coated with an autoantibody causing them to appear incompatible during postreaction testing. Thus, if donor and recipient incompatibility is encountered during a transfusion reaction evaluation, testing of donor RBCs may help resolve issues of serological incompatibility.

Mycophenolate mofetil-induced colitis in children.

Mycophenolate Mofetil (MMF) is a frequently used medication for the maintenance of immunosuppression in pediatric renal transplant patients. It is known to cause mild gastrointestinal side effects. Severe colitis due to MMF is rare and is only described in adults. We report 2 children who presented with severe colitis due to MMF. Infectious and other causes of diarrhea were ruled out. Our patients had diverse histologic findings on colonic biopsies. Patient 1 had histologic features similar to inflammatory bowel disease and patient 2 to graft versus host disease. Withdrawal of MMF resulted in the complete resolution of symptoms in both patients suggesting a causal association. These cases underscore the importance of considering MMF-induced colitis in any patient who presents with diarrhea while on MMF therapy.

Fine-needle aspiration biopsy of recurrent oncocytic carcinoma of parotid gland.

A 65-year-old man presented with a right cheek mass. His past history was significant for resection of primary oncoctyic carcinoma of the right parotid gland 5 years ago. Fine-needle aspiration biopsy of the right cheek mass was performed and demonstrated oncocytic cells without significant cytologic atypia. On the basis of the past history and comparison of the histology of previously resected specimen, the cytologic impression was consistent with recurrent oncocytic carcinoma of the salivary gland. The cytologic differential diagnosis should include other primary salivary gland neoplasms and metastatic disease.

Spectrum of histologic changes in colonic biopsies in patients treated with mycophenolate mofetil.

Mycophenolate mofetil, an immunosuppressive agent, is frequently used following bone marrow and solid organ transplantation. Diarrhea is a commonly seen side effect of mycophenolate mofetil, which may necessitate colonic biopsy in some patients. The histologic changes found in this setting have been reported to mimic self-limited colitis, graft-vs-host disease or inflammatory bowel disease in isolated case reports, and could pose diagnostic and management difficulties. The goal of this study is to define the spectrum of histologic changes in colonic biopsies associated with mycophenolate mofetil usage. All solid organ transplant patients who received mycophenolate mofetil and underwent colonic biopsy for gastrointestinal symptoms from 1999 to 2007 were included in the study. Patients who did not receive mycophenolate mofetil were used as controls. Various histologic features including architectural distortion, apoptosis, inflammatory infiltrate, Paneth cell metaplasia and mucin depletion were subjectively evaluated and scored (scale: 0-3) by two independent reviewers in a blinded fashion. Forty solid organ transplant patients underwent colonic biopsy for gastrointestinal symptoms during the study period. Biopsies from 69% of patients on mycophenolate mofetil showed histologic changes. Apoptosis (41%) and architectural distortion (66%) were seen more frequently in patients receiving mycophenolate mofetil as compared to the control group (13%). The histologic changes in patients receiving mycophenolate mofetil were categorized as normal/near normal (31%), inflammatory bowel disease-like (28%), graft-vs-host disease-like (19%), ischemia-like (3%) and self-limited colitis-like (16%) changes. Of the controls, only one patient showed a graft-vs-host disease-like histologic pattern. In conclusion, histologic changes are frequently associated with mycophenolate mofetil use and can resemble self-limited colitis, graft-vs-host disease and inflammatory bowel disease leading to diagnostic difficulties. Increased awareness of the histologic spectrum of mycophenolate mofetil-induced changes is required by the pathologist to avoid diagnostic errors.