Adult Langerhans cell histiocytosis: a rare cause of colon polyp

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A 65-year-old man with no prior medical problems underwent a screening colonoscopy. He was an ex-smoker with a 100 pack-year cigarette smoking history. A 6-mm sessile, benign-appearing polyp was removed from the descending colon using snare diathermy ([Fig. 1]).

Fig. 1 Endoscopic view of the Langerhans cell histiocytosis polyp.

No other lesions were noted on colonoscopy. Histology showed a nodular proliferation of histiocytic cells within the submucosa, accompanied by a moderate number of eosinophils and lymphoid cells ([Fig. 2] and [3]).

Fig. 2 Medium magnification image of benign colonic mucosa overlying core of polyp, exhibiting pale histiocytic cells and eosinophils (hematoxylin-phloxine-safranin stain, × 100).

Fig. 3 High-magnification image of colonic polyp, exhibiting histiocytic cells with pale cytoplasm and admixed eosinophils (hematoxylin-phloxine-safranin stain, × 400).

Immunoperoxidase studies showed that the histiocytic cells were reactive to S100, CD68, and CD1a antigens ([Fig. 4]).

Fig. 4 Immunoperoxidase reaction of lesional cells with anti-CD1a antibodies, characteristic of Langerhans cells (anti-CD1a with hematoxylin counterstain, × 400).

Based on these results, a diagnosis of Langerhans cell histiocytosis was made. Chest and skull radiographs, bone scan, and an abdominal ultrasound were unremarkable. High-resolution computed tomography of the chest, and bone marrow aspiration and biopsy were normal. As the patient was clinically asymptomatic and the entire work-up did not reveal any other organ involvement, no therapy was initiated; 1 year later, he remains asymptomatic on regular follow-up.

Langerhans cell histiocytosis is rare in adults [1], and gastrointestinal tract involvement is even rarer [2] [3] [4]. With the increasing number of colonoscopies being performed, gastroenterologists should be aware of this rare cause of colon polyps to ensure proper follow-up and further testing to rule out systemic disease.

Endoscopy_UCTN_Code_CCL_1AD_2AC

References

• 1 Stockschlaeder M, Sucker C. Adult Langerhans cell histiocytosis.  Eur J Haematol. 2006;  76 363-368
• 2 Sharma S, Gupta M. A colonic polyp due to Langerhans cell histiocytosis: a lesion not to be confused with metastatic malignant melanoma.  Histopathology. 2006;  49 438-439
• 3 Nihei K, Terashima K, Aoyama K. et al . Benign histiocytosis X of stomach. Previously undescribed lesion.  Acta Pathol Jpn. 1983;  33 577-588
• 4 Iwafuchi M, Watanabe H, Shiratsuka M. Primary benign histiocytosis X of the stomach. A report of a case showing spontaneous remission after 5 œ years.  Am J Surg Pathol. 1990;  14 489-496