Journal of Surgical Oncology 27:219-221 (1984)

Granular Cell Tumor of the Appendix

DEBA P. SARMA, MD, GARY T. SIMMONS, MD, FRED H. RODRIGUEZ, JR. MD, THOMAS G. WEILBAECHER, MD, AND GORDON L. LOVE, MD

From the Department of Pathology, VA Medical Center and Louisiana State University Medical Center, New Orleans

A case of granular cell tumor of appendix occurring in a 58-year-old man is described and the literature is reviewed.

- .___~ ____ KEY WORDS: granular cell tumor, granular cell tumor of appendix, rare tumor of

appendix, rare lesion of appendix

INTRODUCTION

Granular cell tumor is commonly found in the oral cavity and skin. It has been occasionally reported in numerous other anatomic locations. However, granular cell tumor of the appendix is a very rare occurrence. The purpose of this paper is to report such a case and briefly review the English literature.

CASE REPORT A 58-year-old black man underwent an emergency

laparotomy for suspected small bowel obstruction. Div- erticulosis of the transverse colon with perforation was noted. A right hemacolectomy was performed. Post-op- eratively, the patient developed abdominal sepsis and subphrenic abscess and expired about a month later.

The vermiform appendix attached to the resected colon showed a 0.3 cm white firm nodule partially occluding the lumen. The mass was located at about the midportion of the 6 cm iong appendix. Microscopically (Figs. 1, 2) the submucosal unencapsulated tumor was composed of large polygonal cells with indistinct cell borders. The tumor cells showed abundant eosinophilic finely granular cytoplasm. The nuclei were small, round, and uniform. Mitosis or atypicality were not noted. Bands of hyalin- ized and focally calcified collagenous stroma separated the tumor into cell clusters.

Deparaffinized sections were stained for S-100 protein utilizing the peroxidase-antiperoxidase technique. Uni- formly positive staining for S-100 protein was observed in the granular cytoplasm of the tumor.

Ultrastructurally (Fig. 3 ) , the tumor cells were en- closed by a continuous basal lamina and the cytoplasm contained innumerable, irregular, heterogenous mem- brane-bound lysosomal-type granules. No actin-like fila- ments or condensations were noted.

0 1984 Alan R. Liss. Inc.

DISCUSSION There were no clinical symptoms attributable to the

granular cell tumor in our case. This is usually the case, as granular cell tumors are typically slow-growing and asymptomatic. Whereas the oral cavity, skin, and subcu- taneous tissues are the common locations for the granular cell tumor, such lesions have been observed in almost all anatomic locations including the colon [1,2]. A review of the English literature revealed only about three re- ported cases of granular cell tumor of the appendix [3,4]. One of these was an 8 x 4 x 2 mm lesion in the appendix removed for acute appendicitis in a 45-year-old man [ 3 ] . The other two cases were recorded in the Surgical Pa- thology Laboratory of Columbia University [4] ; how- ever, no further details were available. We noted another report [5] where the authors believed that they described a granular cell tumor of the appendix in a 24-year-old woman. However, their microscopic description suggests that the case represented a granular cell degeneration of the muscle coat rather than a true tumor.

The rarity of the granular cell tumor of the appendix is further supported by a review of several large series that examined thousands of surgically excised appendices and reported numerous unusual lesions, but no granular cell tumor [6,7].

Whereas the true granular cell tumor is very rare in the appendix, granular cell degeneration of the smooth muscle of the appendix may be seen in up to 5 % of the appendices [S]. In such cases, the “granular cells” are found in small clusters in the inner muscle coat. Though

Accepted for publication January 17, 1984. Address reprint requests to D. Sarrna, MD, 1601 Perdido Street, New Orleans, Louisiana 70146

220 Sarma et al

Fig. I . Submucosal tumor on the right partially obstructing the lumen (H & E, X 4 )

Fig. 2. Typical microscopic field showing granular cells tumor (H & E. X 120)

Granular Cell Tumor of the Appendix 221

Fig. 3. Electron micrograph showing granular cells enclosed by continuous basal lamina and the cytoplasm filled by membrane bound granules (X4400).

in routine light microscopic study these “granular cells” resemble those of a true granular cell tumor, ultrastruc- turally the presence of actin-like filaments and conden- sations suggest their origin as altered smooth muscle cells.

In spite of extensive clinical and pathologic studies, the exact cell of origin of the granular cell tumor still remains uncertain. However, histochemical and ultrastructural evidences support a Schwann cell derivation for many of the cases.

ACKNOWLEDGMENTS We thank Miss Karen M. Dunn for excellent secretarial

assistance.

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REFERENCES Kanabe S, Watanabe I, Lotuaco L: Multiple granular-cell tumors of the ascending colon. Dis Colon Rectum 21:322-328. 1978. Lack EE, Worsham GF, Callihan MD, Crawford BE, Klappen- bach S, Rowden G, Chun B: Granular cell tumor: A clinicopath- ologic study of 110 patients. J Surg Oncol 13:301-316, 1980. Hausman R: Granular cells in musculature of the appendix. Arch Pathol 75:360-372, 1963. Stout AP: ”Atlas of tumor pathology, Fascile 5.” Washington, DC: Armed Forces Institute of Pathology, p 39. 1953. Barnard PJ, Houston W: Granular cell myoblastoma of the ver- miform appendix. Br J Clin Pract 20:433-434. 1966. Collins DC: 71,000 human appendix specimens. A final report, summarizing forty years’ study. Am J Proctol 14:365-381, 1963. Chang AR: Analysis of the pathology of 3003 appendices. Aust NZ J Surg 51:169-178, 1981. Sobel HJ. Marquet E. Schwarz R: Granular degeneration of ap- pendiceal smooth muscle. Arch Pathol 92:427-432, 197 I .