Whipple's Disease in the Rectum Light and Electron Microscopic Findings
Total Page：16
File Type：pdf, Size：1020Kb
Whipple's Disease in the Rectum Light and Electron Microscopic Findings Agustin Gonzalez-Licea, M.D., and John H. Yardley, M.D. LARGE NuMBERs of PAS-positive macrophages accumulate In the jejunal mucosa of patients with Whipple's disease, and for this rea- son the diagnosis can be made with great accuracy by using a peroral jejunal biopsy. Since similar cells may be found in the rectum of patients with that disease,lA detection by rectal biopsy has also been sug- gested.2S However, the rectum differs from the small intestine in a major respect that is pertinent to Whipple's disease. Unlike the small intestine, macrophages similar to those seen in Whipple's disease are commonly present in rectal tissue, whether it is normal or altered by other conditions. This second type of macrophage, termed a muciphage by Azzopardi and Evans,5 also contains a PAS-positive substance. Muciphages in the rectum not only hamper use of rectal biopsy to detect Whipple's disease, but their occurrence also suggests that the disorder might have different ultrstructural racteristics in the rec- tum. The chief purposes of this study, therefore, were to emine by electron microscopy, Whipple's disease involving the rectum, while giv- ing special attention to features that might be related to muciphage formation and then to contast these findings with Whipple's disease as it is seen in the small intestine. Previous reports i- have shown that the ultrastructure of muciphages differs markedly from macrophages of Whipple's disease in the small intestine. Rectal biopsy specimens from 2 patients with Whipple's disease, one of which showed slight melanosis coli, were investigated. To provide material for comparison, rectal speci- mens showing muciphages and melanosis coli were also studied. Material and Methods Patients Patient 1 (JHH 117 25 97), whose clinical findings have been described pre- viously,s was a 45-year-old male who had had polyarthralgia, fever with occasional From the Department of Pathology, The Johns Hopkins University School of Medicine and Hospital, Baltimre, Md. Supported in part by Grant AM-00660-13 from the U. S. Public Health Service. Dr. Yardley is the recipient of a Research Career Development Award from the U. S. Public Health Service. Accepted for publication Feb. 27, 1968. Address for reprint requests: Dr. Gonzalez-Licea, Centro Medico Nacional, IM.S.S., Apartado Postal 73/032, Mexico City, 73, D.F., Mexico. 1191 1192 GONZALEZ-LICEA AND YARDLEY Vol. 52, No. 6 chills, abdominal bloating, frequent bowel movements, and loss of appetite and weight for 5 years. He showed reduced serum carotene (28 mg./100 ml.), and X-ray examination revealed coarsened jejunal folds. Stool fat and D-xylose excretion were normal. Patient 2 (JHH 121 14 89) was a 40-year-old male with a 7-year history of polyarthralgia and a 1-year history of increasing visual difficulty. Gastrointestinal symptoms were minimal; although mucosal folds in the small intestine were en- larged as seen by X-ray, laboratory tests for malabsorption, performed shortly after antibiotic treatment had been instituted, were all normal. His progressive blindness was caused by an unusual ocular inflammation that was believed to have been related to his Whipple's disease. Intermittent corticosteroid and ACTH treatment had been given over a 1 %-year period for his eye symptoms, but gave only tempo- rary relief. Initial small-bowel biopsies from both patients showed numerous PAS-positive macrophages in the lamina propria. These showed no more than faint staining by the mucicarmine, Alcian blue, or colloidal iron methods. Electron microscopy on both jejunal specimens revealed macrophage granules typical of Whipple's dis- ease 9-14 (Fig. 1). The biopsy from Patient 1 also revealed numerous extra- and intracellular bacteria; 9-14 these were absent in Patient 2, presumably because anti- biotic therapy had been started in the patient 3 weeks previously.18 l4 Both patients showed marked symptomatic response to antibiotic treatment, in- cluding profound improvement in the ocular changes in Patient 2, and there was an associated disappearance of PAS-positive macrophages in subsequent jejunal biopsies from both patients. For control purposes, otherwise normal rectal biopsy specimens containing muciphages were obtained from 3 individuals. One had an Endolimax nana infesta- tion, the second had a rectal stricture, and the third demonstrated Dientamoeba fragilis infestation. Rectal tissue was also obtained from a patient with mucous colitis who showed melanosis coli. Tissue Preparation For light microscopy, rectal biopsy tissue was fixed in either 10% phosphate- buffered formalin or a mixture of formalin, acetic acid, and alcohol. Periodic acid- Schiff (PAS), Alcian blue, mucicarmine, and hematoxylin and eosin staining was done on the tissues from all 5 patients. For electron microscopy, fresh specimens were diced and fixed in chilled 1% phosphate-buffered osmic acid 15 for 45 min. to 1 hr. The tissue was dehydrated in graded alcohols and embedded in Araldite. "Thick" sections (1-2 ,u) of the plastic- embedded material were prepared for light microscopy and stained with toluidine blue and by the PAS reaction.16"17 This permitted accurate localization of PAS- positive macrophages during final trimming of blocks. Ultrathin sections were stained with lead citrate18 or silver methenamine 19 and examined in an RCA EMU 3G or 3H microscope. Results Light Microscopy Muciphages. A general description of these cells will be given to provide a clear definition of the problem posed by their presence in rectal tissue when studying Whipple's disease. Muciphages occur in about 50%o of all rectal specimens,5 a finding June 1968 WHIPPLE'S DISEASE 1193 we have confirmed in our own material; their number can vary from one to many. The cells have a diameter of from about 10 to 40 ,U; they are most numerous in the lamina propria but may also be found in the submucosa when infiltration is heavy. With hematoxylin and eosin staining, muciphages show a moderate-to-large amount of cytoplasm that is most often eosinophilic but is sometimes faintly basophilic and foamy. Their cytoplasm stains with the PAS reaction (Fig. 2, inset), with methods for acid mucins such as Alcian blue (Fig. 2) or colloidal iron, and with mucicarmine. The stained intracytoplasmic material often appears granular, most noticeably after use of acid fixatives. Muciphages also demonstrate yellow-green autofluorescence with ultraviolet illumination.5'7 This finding, which differs markedly from the pale-blue autofluorescence seen with goblet cell mucin, was regarded by Fisher and Hellstrom 7 as evidence that ceroid was contained in foamy cells seen by them in the rectum. The cells which they described, however, had the same staining and ultrastructural characteristics de- scribed for muciphages. Although the matter is not settled, we feel that Azzopardi and Evans 5 were correct in their view that the cytoplasmic material in muciphages is probably epithelial mucin which has passed into the rectal lamina propria and has been phagocytized by macrophages. If this is so, then it must be assumed that the mucin undergoes changes leading to altered autofluorescence after phagocytosis. All 3 rectal specimens used in the present investigation for study of muciphages by electron microscopy showed, by light microscopy, moderate-to-large numbers of cells fitting the above description (Fig. 2). Whipple's Disease. There were no specific cytologic features by which macrophages in the 2 rectal specimens from the patients with Whipple's disease could be unequivocally recognized as due to that disorder rather than to muciphage infiltration. While large numbers of macrophages containing myriads of PAS-postive granules were ob- served in both patients, the rectum of Patient 1 also revealed strong Alcian blue staining of its macrophages (Fig. 3). The same finding was noted in Patient 2, although to a lesser extent. In addition, a small amount of pigment resembling pseudomelanin of melanosis coli was evident in Patient 2. It is noteworthy that the observations in these 2 cases stood in sharp contrast to findings in a rectal specimen from another patient with Whipple's disease reported from this institution.2 In that patient Alcian blue staining of the numerous PAS-positive macrophages seen in the 1194 GONZALEZ-LICEA AND YARDLEY Vol. 52, No. 6 rectum was only faintly positive (Fig. 4). Thus, stains for acid mucins may at times provide a distinction between rectal involvement with Whipple's disease and muciphage infiltration. This would be expected from the fact that not all rectal biopsies show muciphages. Electron Microscopy General Considerations. Rectal macrophages in all material ex- amined were typically of irregular shape, largely because of numerous pseudopodia. Nuclei were ovoid, and nucleoli were not prominent. The endoplasmic reticulum and mitochondria were well developed. Golgi apparatuses and inclusions resembling lysosomes were scanty in some cells and numerous in others. The macrophage cytoplasm in all speci- mens showed variably sized, membrane-bound bodies filled with dif- ferent materials that often seemed to be undergoing digestion. The term "granule" will be applied to these compartmentalized contents of the macrophages. Muciphages. The findings in muciphages were like those previously published.57 There were numerous intracytoplasmic granules which varied in size over a wide range (from about 100 m, to 2 , in diameter). They contained pale material that appeared amorphous at high magnifi- cation (Fig. 5). A darker zone, which may have been due to lipid, was typically present just under the limiting membrane of the smaller-sized granules. Large granules frequently appeared to have been formed by fusion of the smaller ones. Other membrane-bounded electron-dense structures were also noted adjacent to or breaking into the muciphage granules in a few instances. This finding was regarded as evidence of lysozyme transport to the granules.