Myeloid Sarcoma of Appendix Mimicking Acute Appendicitis Eugenio Americo Palomino-Portilla, MD; Jose R. Valbuena, MD; Maria del Pilar Quinones-Avila, MD; L. Jeffrey Medeiros, MD

● Context.—Myeloid sarcoma is a neoplasm of immature myeloid cells involving an extramedullary anatomic site that is usually, although not always, associated with acute myeloid leukemia. Any extramedullary site can be involved by myeloid sarcoma, but involvement of the cecal appendix is uncommon, and symptoms mimicking acute appendicitis as a result of appendiceal involvement are rare. Objective.—To describe the clinicopathologic features of 2 patients with myeloid sarcoma involving the appendix who presented with right lower quadrant pain suggestive of acute appendicitis and prompting appendectomy. Design.—Clinical information for both patients was obtained from the medical record. Routine hematoxylineosin–stained slides, naphthol-ASD-chloroacetate stain, and immunohistochemical stains for myeloid, B-cell, and T-cell antigens were prepared.

Results.—Peripheral blood and bone marrow were infiltrated by coexistent acute myeloid leukemia in case 1 but were negative for leukemia in case 2. In case 2, the patient had a history of acute myeloid leukemia that had been treated by an allogenic bone marrow transplant 7 months earlier. Histologic examination of the appendix revealed poorly differentiated myeloid sarcoma in both cases. Each neoplasm was positive for chloroacetate esterase, myeloperoxidase, lysozyme, and CD43 and was negative for CD3 and CD20. Conclusions.—Myeloid sarcoma involving the appendix can rarely cause pain or other symptoms mimicking acute appendicitis. A high index of suspicion combined with the use of cytochemical and immunohistochemical studies are helpful in establishing the diagnosis. (Arch Pathol Lab Med. 2005;129:1027–1031)

M

the cecal appendix, with symptoms mimicking acute appendicitis and prompting appendectomy.

yeloid sarcoma (MS) is a neoplasm composed of immature myeloid cells that can arise at any extramedullary anatomic site.1 Myeloid sarcoma was first described by Burns in 1811,2 and a variety of names in the literature have been used for these neoplasms, including granulocytic sarcoma, monocytic sarcoma, extramedullary myeloid cell tumor, myelosarcoma, myeloblastoma, and chloroma.2–7 The term MS was first used by Fayemi et al in 1973.8 A wide variety of extramedullary sites can be affected by MS, and the clinicopathologic features of MS involving different anatomic sites have been addressed in several studies.1,9–11 However, MS involving the cecal appendix is uncommon. Furthermore, MS involving the appendix and causing symptoms that clinically mimic acute appendicitis is extremely rare. We have identified only 2 cases reported in the literature.12,13 In the present study, we describe the clinicopathologic features of 2 patients who presented with MS involving

Accepted for publication April 19, 2005. From the Department of Pathology, Edgardo Rebagliati Hospital, Lima, Peru (Drs Palomino-Portilla and Quinones-Avila); and the Department of Hematopathology, The University of Texas M. D. Anderson Cancer Center, Houston (Drs Valbuena and Medeiros). The authors have no relevant financial interest in the products or companies described in this article. Corresponding author: L. Jeffrey Medeiros, MD, Department of Hematopathology, Box 72, The University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Blvd, Houston, TX 77030 (e-mail: jmedeiro@ mdanderson.org). Arch Pathol Lab Med—Vol 129, August 2005

MATERIALS AND METHODS We reviewed the files of the Department of Pathology, Edgardo Rebagliati Hospital, in Lima, Peru, and the Department of Hematopathology at The University of Texas M. D. Anderson Cancer Center, Houston, and identified 2 patients with MS involving the appendix. Clinical information at the time of diagnosis and follow-up was available for both patients. The radiologic findings of case 2 have been reported previously.14 Hematoxylin-eosin–stained slides were prepared using formalin-fixed, paraffin-embedded tissue sections. The Leder method was used to assess for naphthol–ASD–chloroacetate esterase.15 Both cases were classified using the criteria of the World Health Organization (WHO) classification for hematolymphoid neoplasms.1 Immunohistochemical stains were performed using formalinfixed, paraffin-embedded tissue sections, heat-induced epitope retrieval, an avidin-biotin complex method, and an automated immunostainer (Ventana Medical System, Tucson, Ariz) as previously described.16 The antibodies used to assess these cases included reagents specific for CD3, CD20, CD43, CD68, CD117 (c-Kit), myeloperoxidase, and lysozyme (Dako Corporation, Carpinteria, Calif).

RESULTS Clinical Findings The clinical findings of both patients are summarized in the Table. Case 1 A 9-year-old Peruvian girl, without previous medical illness, came to the hospital complaining of a 5-day history MS Mimicking Acute Appendicitis—Palomino-Portilla et al 1027

Summary of Myeloid Sarcomas Involving the Appendix*

Source, y

Age, y/Sex

RLQ Pain

History of Hematologic Disorder

Blasts in PB at the Time of Appendiceal Involvement, %

Type of AML (FAB)

Clinical Follow-up

77/F 1 — 7 M3 Dead, 1 mo 71/M 1 — 83 M2 Dead, 49 d 9/F 1 — 77 M4 ANED, 27 mo 29/M 1 AML S/P BMT 0 M2 AWD, 16 mo * RLQ indicates right lower quadrant; PB, peripheral blood; AML, acute myeloid leukemia; FAB, French-American-British classification; ANED, alive, no evidence of disease; S/P BMT, status post bone marrow transplant; and AWD, alive with disease. Muller et al, 1997 Toubai et al,13 2003 Present study 12

of right lower quadrant abdominal pain, fever, diarrhea, nausea, vomiting, and gum bleeding. She denied recent travel. Physical examination disclosed the following values: temperature, 378C; blood pressure, 90/60 mm Hg; pulse, 120 beats per minute; and respirations, 24 breaths per minute. She had pale skin, slight dehydration of the oral mucosa, bleeding gums, axillary and cervical lymphadenopathy, hepatomegaly that was palpable 5 cm inferior to the right costal margin, a distended abdomen, abdominal guarding, and right lower quadrant abdominal pain. Bowel sounds were present. Laboratory tests performed in the emergency department at this time disclosed the following values: white blood cell count, 48 600/mL (reference range, 4000–11 000/mL); hemoglobin level, 9.8 g/ dL (reference range, 12.0–16.0 g/dL); and platelet count, 68 000/mL (reference range, 140 000–440 000/mL). The white blood cell differential count showed 15% neutrophils, 7% lymphocytes, 19% eosinophils, 3% bands, and 77% blasts. The bone marrow was aspirated, showing numerous blasts with cytologic features suggestive of monocytic differentiation. Flow cytometry immunophenotypic analysis of bone marrow aspirate material showed that the blasts were positive for CD2 (dim), CD13 (bright), myeloperoxidase, and HLA-DR and that they were negative for CD3, CD7, CD10, CD19, and CD79a. The diagnosis of acute myelomonocytic leukemia (WHO classification) or M4 (French-American-British classification [FAB]) was established. An abdominal ultrasound showed intestinal ileus, related to edema of the intestinal wall. The patient continued to experience right lower quadrant abdominal pain and fever, which prompted an appendectomy 1 week after her arrival at the hospital. Mesenteric lymphadenopathy was also observed during the operation, but a biopsy of these lymph nodes was not performed. Following the operation, the patient was initially placed in the intensive care unit because of coagulopathy caused by leukemia and sepsis, bilateral bronchopneumonia, and sepsis. Mechanical ventilation was required. Following chemotherapy and supportive therapy, the patient recovered, and she was clinically without evidence of acute leukemia at the time of her last follow-up, 27 months after diagnosis. Case 2 A 29-year-old man came to the hospital with a 1-week history of episodic right lower quadrant pain. He did not have nausea, vomiting, fever, chills, or diarrhea. The patient had a history of acute myeloid leukemia with maturation (WHO), or M2 (FAB), first diagnosed 10 months earlier. Flow cytometry immunophenotypic analysis performed on bone marrow aspirate at that time showed that the blasts were positive for CD7, CD11c, CD13, CD33, CD34 (dim), myeloperoxidase, and HLA-DR and were 1028 Arch Pathol Lab Med—Vol 129, August 2005

negative for other B- and T-cell antigens. He was treated initially with chemotherapy, and 3 months later, he underwent an allogeneic bone marrow transplantation. Physical examination disclosed the following values: temperature, 37.48C; blood pressure, 114/56 mm Hg; pulse, 85 beats per minute; and respirations, 20 breaths per minute. The abdomen was soft, nontender, and nondistended, and bowel sounds were present. A reducible umbilical hernia was evident. No rebound tenderness or abdominal guarding was evident. Routine laboratory tests disclosed a white blood cell count of 8400/mL with a normal differential count and a hemoglobin level of 14.7 g/ dL. Computed tomographic scans of his abdomen and pelvis showed an enlarged, thick-walled appendix and inflammatory changes, consistent with acute appendicitis. An appendectomy was performed. In addition, biopsy specimens of abdominal, mesenteric, and omental nodules were obtained. Shortly after the operation, a bone marrow aspiration and biopsy were performed. There was no morphologic or immunophenotypic evidence of acute myeloid leukemia, and conventional cytogenetic analysis of bone marrow aspirate material showed a normal karyotype. Six months later, the patient relapsed with right testicular enlargement without a discrete mass and, in addition, had disease involving the visceral peritoneum, omentum, and kidneys. Involvement of the ileum was prominent, which caused the formation of a mass and obstruction. Fine-needle aspiration of the testis was positive for leukemic cells. At this time, the white blood cell count was 10 400/mL with the following differential count: neutrophils, 69%; bands, 16%; lymphocytes, 7%; monocytes, 4%; eosinophils, 3%; and metamyelocytes, 1%. The hemoglobin level was 12.6 g/dL, and the platelet count was 242 000/mL. The patient was treated with palliative radiotherapy and was alive with persistent acute myeloid leukemia/MS at last follow-up, 16 months after the initial diagnosis. Gross and Histologic Findings Grossly, in case 1, the appendix was 8 3 1 cm with red granular serosa. The lumen was patent without fecaliths. In case 2, the appendix was 8.0 3 0.9 cm with red serosa. The lumen was patent without fecaliths. Biopsy specimens of abdominal, mesenteric, and omental nodules ranged from 1.2 to 6.2 cm in their greatest dimension. Histologically, at low-power magnification, the neoplastic infiltrate in case 1 filled and distended the mucosa and lamina propria, with lesser involvement of the muscularis and focal extension to the serosa (Figure 1). Neoplastic cells were also focally identified in the surrounding adipose tissue with the involvement of lymphatics and blood vessels. By contrast, in case 2, the neoplasm extensively surrounded the appendix and involved the adipose tissue MS Mimicking Acute Appendicitis—Palomino-Portilla et al

Figure 1. Case 1. Myeloid sarcoma. The neoplasm predominantly filled and distended the lamina propria and mucosa, with lesser involvement of the appendiceal wall (hematoxylin-eosin, original magnification 320). Figure 2. Case 2. Myeloid sarcoma. A, The neoplasm predominantly involved the serosa and outer muscularis propria of the appendix. B, In this field, the neoplastic cells are infiltrating the muscularis propria in a single-file pattern (hematoxylin-eosin, original magnifications 320 [A] and 3200 [B]). Figure 3. Case 1. Myeloid sarcoma. The neoplastic cells had round or folded nuclear contours, conspicuous nucleoli, and a variable amount of cytoplasm (hematoxylin-eosin, original magnification 3400).

(Figure 2, A) and serosa (Figure 2, B) and partially involved the muscularis propria. At high-power magnification, both neoplasms were poorly differentiated as described previously.17,18 In case 1, the neoplastic cells were medium to large, with round or folded nuclear contours, 1 or 2 small nucleoli, and a variable amount of cytoplasm (Figure 3). Some of the neoplastic cells had c-shaped or reniform nuclei suggestive of monocytic differentiation. The neoplastic cells in case 2 were predominantly large with round or folded nuclear contours, thin nuclear membranes, prominent eosinophilic nucleoli, and a scant-to-moderate amount of cytoplasm (Figure 4). Mature and immature eosinophils were sparse in both cases. Mitotic figures were easily identified in both cases and ranged from 2 to 3 per high-power field in areas with the greatest number. In case 1, mitotic figures ranged from 7 to 9 per 10 high-power fields, and in case 2, mitotic figures ranged from 12 to 13 per 10 high-power fields. In case 2, the additional biopsy specimens obtained from the nodules that were designated abdominal, mesenteric, and omental showed extensive involvement by Arch Pathol Lab Med—Vol 129, August 2005

MS, histologically resembling the neoplasm in the appendix. Cytochemical and Immunohistochemical Findings Napthol–ASD–chloroacetate esterase was positive in both cases. In case 1, the neoplastic cells were positive for CD43, CD68, CD117, lysozyme, and myeloperoxidase (Figure 5). In case 2, the neoplastic cells were positive for CD43, CD68, lysozyme (Figure 6), and myeloperoxidase. In both cases, the neoplastic cells were negative for CD3 and CD20. COMMENT At autopsy, involvement of the gastrointestinal tract by acute myeloid leukemia is detected in 7% to 20% of patients.7,19–21 Grossly, leukemic infiltrates can involve the gastrointestinal tract as nodules, plaques, or ulcerative lesions.19,20 The organs of the gastrointestinal tract that are involved most often are the stomach, proximal colon, and terminal ileum. The esophagus, duodenum, jejunum, and distal colon are involved less frequently.19,20 Leukemic inMS Mimicking Acute Appendicitis—Palomino-Portilla et al 1029

Figure 4. Case 2. Myeloid sarcoma. The neoplastic cells were large with round or folded nuclear contours and more prominent nucleoli than case 1. A neoplastic cell with abundant eosinophilic cytoplasm is present in the center of the field (hematoxylin-eosin, original magnification 31000). Figure 5. Case 1. Myeloid sarcoma. The neoplastic cells are strongly positive for myeloperoxidase (immunohistochemistry with hematoxylin counterstain, original magnification 3400). Figure 6. Case 2. Myeloid sarcoma. The neoplastic cells are strongly positive for lysozyme (immunohistochemistry with hematoxylin counterstain, original magnification 3400).

filtrates that involve the appendix are uncommon and were observed in only 3 (8.3%) of 36 patients in one study by Prolla and Kirsner.20 By contrast, MS involving the appendix is uncommon and rarely causes symptoms that mimic acute appendicitis. In our review of the literature, we have identified only 1030 Arch Pathol Lab Med—Vol 129, August 2005

2 cases.12,13 Including the 2 cases we report, 4 cases are now documented in the literature and are summarized in the Table. The age of these patients ranged from 9 to 77 years (mean, 46.7 years). All 4 patients had right lower quadrant pain. Two patients had acute myeloid leukemia with maturation (FAB-M2), one patient had acute myelomonocytic leukemia (FAB-M4), and one patient had acute promyelocytic leukemia (FAB-M3). For 3 patients, the diagnosis of acute leukemia involving blood and bone marrow was established at virtually the same time the appendectomy was performed. In one patient (case 2 of this study), appendiceal involvement by MS occurred after the initial diagnosis of acute myelomonocytic leukemia 10 months earlier, and 7 months following an allogeneic bone marrow transplant. To our knowledge, there are no cases reported of MS involving the appendix and mimicking acute appendicitis without coexistent, or a history of, acute myeloid leukemia. Necrotizing enterocolitis and acute appendicitis are 2 diseases that are part of the differential diagnosis of right lower quadrant pain in a patient with leukemia, and both are more common than MS involving the appendix. The risk of necrotizing enterocolitis in leukemic patients is related to the degree of neutropenia, defined as an absolute neutrophil count of less than 500/mL.22–25 Typhlitis, a localized form of necrotizing enterocolitis, is characterized by dilatation of the ascending colon, with fluid accumulation around the cecum and a thickened appendix, and can cause symptoms and signs similar to those of acute appendicitis. Clinically, patients present with abdominal distension, right lower quadrant pain, fever, nausea, vomiting, and lower gastrointestinal bleeding.24,25 Similarly, acute appendicitis can occur in leukemic patients, with an increased risk of occurrence in patients with neutropenia.26–29 Usually, symptoms and signs attributable to acute appendicitis are more localized to the right lower quadrant than necrotizing enterocolitis. Histologically, distinguishing necrotizing enterocolitis or acute appendicitis from MS is usually not difficult.24,27 Necrotizing enterocolitis usually involves large areas of the intestine, including the appendix, and microscopically is characterized by loss of the mucosa, with prominent edema and infarction of the submucosa and muscular wall without a substantial inflammatory infiltrate. Acute appendicitis is characterized by a neutrophilic infiltrate in the submucosa, muscularis, and serosa, with abscess in florid cases. Myeloid sarcoma involving the appendix can mimic other types of malignant neoplasms, with the major differential diagnosis being malignant lymphomas, especially large B-cell lymphoma.1 Lymphomas are more likely to form masses in the appendix, in contrast with MS. At low power, large cell lymphoma is often associated with architectural destruction and necrosis within the tumor. In contrast, MS tends to infiltrate tissue planes, preserving the tissue architecture without extensive destruction or tumor necrosis. Cytologically, the cells of large cell lymphoma have thick nuclear membranes, vesicular nuclear chromatin, and distinct nucleoli, in contrast to the cells of MS. The latter usually have more immature nuclear chromatin, with reniform nuclei in monocytic tumors. Myeloid sarcoma also can be mistaken for Burkitt lymphoma, as these tumors can rarely involve the appendix, and symptoms can mimic acute appendicitis.30,31 A ‘‘starry-sky’’ pattern is one of the most striking histologic features of Burkitt lymphoma, but MS can have a similar MS Mimicking Acute Appendicitis—Palomino-Portilla et al

pattern. However, Burkitt lymphoma cells are mediumsized, with ‘‘squared-off’’ cytoplasmic borders, multiple nucleoli, and scant basophilic cytoplasm, in contrast with the cytologic features of MS.4,30 Cytochemical and immunohistochemical stains were helpful in the recognition of MS, as has been reported by others.5,6,17 Both neoplasms in this study were positive for naphthol–ASD–chloroacetate esterase as well as a number of myeloid antigens, including myeloperoxidase, lysozyme, and CD68. Myeloperoxidase and lysozyme are the most specific immunohistochemical markers of myeloid differentiation that are routinely available.5,6,17 Both neoplasms were negative for B- and T-cell–specific antigens. In summary, we have described 2 cases of MS involving the appendix that caused symptoms mimicking acute appendicitis. Two other cases have been previously reported in the literature. A variety of types of acute myeloid leukemia have been associated with MS in these patients, and all patients had coexistent acute myeloid leukemia or a history of acute myeloid leukemia at the time of the diagnosis of MS. We thank Pedro Chacon, MD, and H. Alejandro Yabar, MD, Chairman of Pathology Department and Chairman of Pathology Service 2, respectively, at Edgardo Rebagliati Hospital, Lima, Peru. References 1. Brunning RD, Matutes E, Flandrin G, et al. Myeloid sarcoma. In: Jaffe ES, Harris NL, Stein H, Vardiman JW, eds. Pathology and Genetics of Tumours of Hematopoietic and Lymphoid Tissues. Lyon, France: IARC Press; 2001:104–105. World Health Organization Classification of Tumours; vol 3. 2. Burns A. Observations of Surgical Anatomy, Head and Neck. Edinburgh: Thomas Royce & Co; 1811:364–366. 3. Liu PI, Ishimaru T, McGregor DH, Okada H, Steer A. Autopsy study of granulocytic sarcoma (chloroma) in patients with myelogenous leukemia, HiroshimaNagasaki 1949–1969. Cancer. 1973;31:948–955. 4. Neiman RS, Barcos M, Berard C, et al. Granulocytic sarcoma: a clinicopathologic study of 61 biopsied cases. Cancer. 1981;48:1426–1437. 5. Furebring-Freden M, Martinsson U, Sundstrom C. Myelosarcoma without acute leukemia: immunohistochemical and clinico-pathologic characterization of eight cases. Histopathology. 1990;16:243–250. 6. Roth MJ, Medeiros LJ, Elenitoba-Johnson K, Kuchnio M, Jaffe ES, StetlerStevenson M. Extramedullary myeloid cell tumors: an immunohistochemical study of 29 cases using routinely fixed and processed paraffin-embedded tissue sections. Arch Pathol Lab Med. 1995;119:790–798. 7. Menasce LP, Banerjee SS, Beckett E, Harris M. Extra-medullary myeloid tumor (granulocytic sarcoma) is often misdiagnosed: a study of 26 cases. Histopathology. 1999;34:391–398.

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8. Fayemi AO, Gerber MA, Cohen I, Davis S, Rubin AD. Myeloid sarcoma: review of the literature and report of a case. Cancer. 1973;32:253–258. 9. Schmitt-Graff A, Wickenhauser C, Kvasnicka HM, Dries V, Thiele J. Extramedullary initial manifestations of acute myeloid leukemia. Pathologe. 2002;23: 397–404. 10. Meis JM, Butler JJ, Osborne BM, Manning JT. Granulocytic sarcoma in nonleukemic patients. Cancer. 1986;58:2697–2709. 11. Elenitoba-Johnson K, Hodges GF, King TC, Wu CD, Medeiros LJ. Extramedullary myeloid cell tumors arising in the setting of chronic myelomonocytic leukemia: a report of two cases. Arch Pathol Lab Med. 1996;120:62–67. 12. Muller G, Dargent JL, Duwel V, et al. Leukaemia and lymphoma of the appendix presenting as acute appendicitis or acute abdomen: four case reports with a review of the literature. J Cancer Res Clin Oncol. 1997;123:560–564. 13. Toubai T, Kondo Y, Ogawa T, et al. A case of leukemia of the appendix presenting as acute appendicitis. Acta Haematol. 2003;109:199–201. 14. Khatti S, Faria SC, Medeiros LJ, Szklaruk J. Myeloid sarcoma of the appendix mimicking acute appendicitis. AJR Am J Roentgenol. 2004;182:1194. 15. Leder LD. On the selective enzyme-cytochemical demonstration of neutrophilic myeloid cells and tissue mast cells in paraffin sections. Klin Wochenschr. 1964;1:553. 16. Park CK, Manning JT, Battifora H, Medeiros LJ. Follicle center lymphoma and Warthin tumor involving the same anatomic site: report of two cases and review of the literature. Am J Clin Pathol. 2000;113:113–119. 17. Traweek ST, Arber DA, Rappaport H, Bryrnes RK. Extramedullary myeloid cell tumors: an immunohistochemical and morphologic study of 28 cases. Am J Surg Pathol. 1993;17:1011–1019. 18. Valbuena JR, Admirand JH, Gualco G, Medeiros LJ. Myeloid sarcoma involving the breast. Arch Pathol Lab Med. 2005;129:32–38. 19. Cornes JS, Jones TG. Leukemic lesions of the gastrointestinal tract. J Clin Pathol. 1962;15:305–313. 20. Prolla JC, Kirsner JB. The gastrointestinal lesions and complications of the leukemias. Ann Intern Med. 1964;61:1084–1103. 21. Viadana E, Bross DJ, Pickren JW. An autopsy study of the metastatic patterns of human leukemias. Oncology. 1978;35:87–96. 22. Hunter TB, Bjelland JC. Gastrointestinal complications of leukemia and its treatment. AJR Am J Roentgenol. 1984;142:513–518. 23. Martell RW, Jacobs P. Surgery for the acute abdomen in adults with leukaemia. Postgrad Med J. 1986;62:915–918. 24. Katz JA, Wagner ML, Gresik MV, Mahoney DH Jr, Fernbach DJ. Typhlitis: an 18-year experience and postmortem review. Cancer. 1990;65:1041–1047. 25. Paulino AF, Kenney R, Forman EN, Medeiros LJ. Typhlitis in a patient with acute lymphoblastic leukemia prior to administration of chemotherapy. Am J Pediatr Hematol Oncol. 1994;16:348–351. 26. Angel CA, Rao BN, Wrenn E Jr, Lobe TE, Kumar AP. Acute appendicitis in children with leukemia and other malignancies: still a diagnostic dilemma. J Pediatr Surg. 1992;27:476–479. 27. Kim KU, Kim JK, Won JH, Hong DS, Park HS. Acute appendicitis in patients with acute leukemia. Korean J Intern Med. 1993;8:40–45. 28. Moyana TN, Kulaga A, Xiang J. Granulomatous appendicitis in acute myeloblastic leukemia expanding the clinicopathologic spectrum of invasive candidiasis. Arch Pathol Lab Med. 1996;120:203–205. 29. Turrini O, Moutardier V, Vey N, Guiramand J, Lelong B, Delperro JR. Sometimes appendicitis can wait. Am J Hematol. 2004;76:312–313. 30. Sin IC, Ling ET, Prentice RS. Burkitt’s lymphoma of the appendix: report of two cases. Hum Pathol. 1980;11:465–470. 31. Bissen L, Brasseur R, Azagra JS, Deiree P. Burkitt’s lymphoma of the appendix. JBR-BTR. 2002;85:257–259.

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