Pathologic Quiz Case: A 55-Year-Old Woman With a History of Treated Hodgkin Disease and a Persistent Abdominal Mass

A 55-year-old woman was diagnosed in 1984 as having stage IV Hodgkin disease. She was treated with a contemporary regimen but relapsed in 1999 with involvement of the cervical and ileocolic lymph nodes and bone marrow. Computed tomography images of the abdomen revealed an ileocecal mass, with intramural involvement of the cecal wall (Figure 1). The patient responded well to multiple cycles of chemotherapy; however, the abdominal mass persisted. A biopsy specimen revealed fibrosis and chronic nonspecific inflammation. A subsequent biopsy specimen taken a year later once again revealed fibrosis and chronic nonspecific inflammation. The mass was subsequently resected.The surgical specimen consisted of a 29.0-cm segment of ileum and cecum. A tan-white mass that measured 3.0 × 3.0 × 4.0 cm was observed, producing marked intramural thickening of the cecum and narrowing of the lumen. Adjacent to the mass, the mucosa was exaggerated into folds up to 2.0 cm in diameter and 1.0 cm in thickness. The serosal surface of the cecum revealed multiple fibrous adhesions. Microscopic examination of the cecal mass revealed a transmural infiltrate composed of acute and chronic inflammatory cells and histiocytes. The histiocytes had abundant cytoplasm and contained numerous lymphocytes (Figure 2) and karyorrhectic debris. Extensive fibrosis was also present. The exaggerated mucosal folds demonstrated fibrosis, inflammatory cells, and histiocytes with similar phagocytic activity as described herein. Immunohistochemically, the histiocytes were S100 positive (Figure 3) and were CD1a, CD15, and CD30 negative. The lymphocytes within the histiocytes were immunoreactive for both CD3 and CD20.What is your diagnosis?Rosai-Dorfman disease (RDD) is a rare proliferative histiocytic disorder of unknown origin. In 1969, Rosai and Dorfman described several cases and suggested the name “sinus histiocytosis with massive lymphadenopathy.”1 Most patients are young (mean age of onset, 20.6 years), although there may be wide age distribution at presentation, ranging from newborn to 74 years of age.2 Patients present with massive painless cervical lymphadenopathy.2 Affected lymph nodes reveal dilated sinuses infiltrated by histiocytes, which frequently contain phagocytized lymphocytes (emperipolesis).3 The clinical course is usually self-limited, with a tendency for total spontaneous regression. Extranodal involvement occurs in approximately 40% of cases, and practically every organ system can be affected. The gastrointestinal tract is the least commonly involved site,3 and only rare cases are reported to clinically present with an intestinal tumor mass.This case clinically posed a diagnostic dilemma. With the past medical history of Hodgkin disease and a tumor mass in the cecum, the possibility of recurrent Hodgkin disease could not be excluded, and gastrointestinal biopsy specimens taken before resection of the mass were nondiagnostic. Although the pathologic features of RDD are distinctive, there are several other diseases that should be considered in the differential diagnosis, particularly in extranodal lesions. Since cases of coexistent Hodgkin disease and RDD have been reported,4 multiple histologic sections were examined to exclude this possibility. The histiocytic component in this lesion was not immunoreactive for CD15 and CD30. Rare examples of an uncommon malignant histiocytic neoplasm of the small bowel have also been described.5 In this latter condition, the cells commonly phagocytize erythrocytes and reveal nuclear atypia and increased mitotic activity.6 Langerhans cell histiocytosis is also a consideration in the differential diagnosis. In this condition, a proliferation of cytologically benign histiocytes with a unique (“coffee bean”) nuclear groove are observed. The histiocytes of Langerhans cell histiocytosis are immunoreactive for S100 and CD1a and do not reveal emperipolesis.It is of interest that extranodal RDD only rarely manifests in the gastrointestinal tract.36 The extensive nature of the disease and the past medical history of Hodgkin disease in this patient prompted careful examination and exclusion of the latter.