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An Unusual Presacral Mass: Extramedullary Hematopoiesis
Gastrointestinal Images An Unusual Presacral Mass: Extramedullary Hematopoiesis Ilan Youngster, M.D., Michael Weiss, M.D., Assi Drobot, M.D., Arieh Eitan, M.D.
Presacral masses are a rare finding in the adult patient, confronting the physician with diagnostic and therapeutic challenges. We present an unusual case of a symptomatic presacral mass caused by extramedullary hematopoietic tissue in a thalassemic patient and review the unique aspects of this entity. ( J GASTROINTEST SURG 2006;10:927–929) Ó 2006 The Society for Surgery of the Alimentary Tract KEY
WORDS:
Extramedullary hematopoiesis, presacral mass, b-thalassemia intermedia
Presacral (retrorectal) tumors are particularly rare in the adult. They usually present with vague symptoms and are a diagnostic challenge due to difficulty in the performance of diagnostic biopsy and the need for specialized imaging required to plan surgical extirpation.1 Traditionally, these masses are classified as cystic or solid lesions. Most cystic lesions are developmental cysts (mainly dermoid and epidermoid cysts, tailgut cysts, and cystic hamartomas),1 and the majority of the solid lesions are neoplasms (mainly chordomas).1,2 We, herein, present a patient with a symptomatic, solid lesion that does not fall into any of these categories. CASE REPORT A 48-year-old female presented to our institution complaining of painful defecation that had been bothering her for the last 3 months. There was no history of weight loss or change in bowel habits. She was diagnosed with b-thalassemia intermedia at 8 years of age, has never been in need of blood transfusions, and was lost to follow-up during the last 10 years. Her physical examination was unremarkable except for an enlarged spleen. Rectal
digital examination revealed a tender posterior mass with a soft consistency and a smooth contour. Her laboratory workup was remarkable for a microcytic anemia with hemoglobin values of 9.7 g/dL, mean corpuscular volume (MCV) 63.7 fL, and platelets 90,000/mm3. A computed tomography scan showed a 3 3 3 3 5-cm smoothly marginated, solid, presacral mass. No abnormal lymph nodes were detected. Hepatosplenomegaly was also present. As part of the preoperative survey, magnetic resonance imaging was performed. The mass showed a high-signal intensity on T1 and T2 weight images (Fig. 1), and was uniformly enhanced after gadolinium injection. Due to the unclear nature of the mass, a diagnostic excision was performed. A posterior approach was used to reach the presacral space. The mass was encapsulated by soft, smooth fibrotic tissue and was firmly adherent to the posterior wall of the rectum, without evidence of invasion. The mass was extirpated as a whole (Fig 2). The pathologic examination of the mass showed fatty connective tissue interspaced with bone marrow trabeculae and hyperplastic hematopoietic cells (Fig 3), all consistent with a diagnosis of extramedullary hematopoiesis (EH).
From the Department of Surgery, Western Galilee Medical Center, Nahariya, Israel. No financial support has been granted for the work described in this article and no involvement exists with any organization with an interest in the subject matter. Reprint requests: Dr. Ilan Youngster, Western Galilee Medical Center, Dept. of Surgery, 23 Nes-ziona 74077, Israel. e-mail: ilanyoungster@ yahoo.com Ó 2006 The Society for Surgery of the Alimentary Tract Published by Elsevier Inc.
1091-255X/06/$dsee front matter doi:10.1016/j.gassur.2005.05.010
927
928
Youngster et al.
Journal of Gastrointestinal Surgery
Fig. 3. Microscopic examination of the mass revealing hyperplastic hematopoietic tissue. Fig. 1. Magnetic resonance imaging of the abdomen and pelvis: sagital view. A clearly demarcated presacral mass is shown.
The postoperative course was uneventful. The patient was discharged on the fourth postoperative day. On subsequent follow-up 12 months later, the patient was completely asymptomatic.
DISCUSSION EH is the development and growth of hematopoietic tissue outside of the bone marrow. After birth, it is considered abnormal and is usually a compensatory phenomenon in diseases of reduced erythrocyte production or accelerated erythrocyte destruction.3 The most commonly associated conditions are myelofibrosis with myeloid metaplasia, and thalassemia
Fig. 2. Specimen after surgical extraction.
(mainly b-thalassemia intermedia).3 The liver and spleen are the most common sites involved in pathologic EH. However, the process has been described in various other sites, especially the intrathoracic paravertebral location.3,4,5 In a retrospective chart review by Cody et al.3 of 510 cases involving EH, only 27 (5.3%) were nonhepatosplenic. Of these 27 cases, 7 (26%) were paravertebral, and the rest involved various lymph nodes (15%), retroperitoneum (15%), pleura (11%), and other less common sites. The presacral space is a particularly rare site of EH, and to date only a few other cases have been described in English literature.3–8 Clinically, EH may present as an incidental finding or with local symptoms and signs of a mass effect. The radiographic appearance of EH has been described previously in various studies, but is generally nondiagnostic. CT scan shows a heterogeneous lobulated soft tissue density mass with a sharp demarcation.4 Magnetic resonance imaging (MRI) usually demonstrates a high-signal intensity on T1 and T2 weighted images.4,7 Other diagnostic modalities include 99mTc sulfur colloid bone marrow scan and angiography.3,7 The management of these lesions is influenced by the symptoms. Asymptomatic masses can be observed safely without surgical intervention. Symptomatic masses require treatment. Ectopic hematopoietic tissue has been shown to be extremely sensitive to low doses of radiation. Koch et al. showed a 71% response rate to a radiation dose of 4.25 Gy delivered in 10 fractions.3 In our case the management was influenced by the symptoms and the unusual site of growthdthe presacral space. Although at least half of the presacral tumors presenting in the adult are asymptomatic, and the majority are benign, it is generally recommended that these lesions be removed.1 The role
Vol. 10, No. 6 2006
of preoperative biopsy is controversial. Biopsy can be followed by serious and even fatal complications, including infections and bleeding from damage to the middle sacral artery.1 Wolpert et al. recommended that preoperative biopsy be done only in solid lesions with signs of malignancy such as sacral invasion.1 If a presacral needle biopsy is decided upon, it must be done in such a way that the needle tract can be excised en bloc with the tumor should operative excision be subsequently performed.1,4 In patients suffering from chronic blood dyscrasias, the possibility of EH should be taken into account during initial evaluation of space-occupying lesions. The presence of symptoms dictates the proper management, which can consist of radiographic follow-up only, radiation treatment, or surgical excision. In our case the unusual site of growth, combined with the fact that the patient was symptomatic, made us choose the surgical option.
Presacral Extramedullary Hematopoiesis
929
REFERENCES 1. Wolpert A, Beer-Gabel M, Lifschitz O, et al. The management of presacral masses in the adult. Tech Coloproctol 2002;6:43–49. 2. Stewart RJ, Humphreys WG, Parks TG. The presentation and management of presacral tumors. Br J Surg 1986;73: 153–155. 3. Koch A, Li C-Y, Mesa R, et al. Nonhepatosplenic extramedullary hematopoiesis: Associated diseases, pathology, clinical course, and treatment. Mayo Clin Proc. 2003;78:1223–1233. 4. Miyake H, Matsuda M, Iyomasa S, et al. Presacral extramedullary hematopoiesis. Surgery 2004;135:112–113. 5. Sarmiento M, Wolff BG. A different type of presacral tumor: Extramedullary hematopoiesis. Dis Colon Rectum 2003;46: 683–685. 6. Newton KL, McNeeley G, Novick M. Extramedullary hematopoiesis presenting as a pelvic mass in a patient with b-thalassemia intermidia. JAMA 1983;250:2178–2179. 7. Karak P, Shoukri KC, Spencer RP, et al. Presacral hematopoietic tissue: correlation of radionuclide and MRI findings. Clin Nucl Med 1998;23:330–331. 8. Gemenis T, Philippou A, Gouliamos A, et al. Atypical location of extramedullary hematopoietic masses in thalassemia. Radiologe 1989;29:295–296.
Presacral masses are a rare finding in the adult patient, confronting the physician with diagnostic and therapeutic challenges. We present an unusual case of a symptomatic presacral mass caused by extramedullary hematopoietic tissue in a thalassemic patient and review the unique aspects of this entity. ( J GASTROINTEST SURG 2006;10:927–929) Ó 2006 The Society for Surgery of the Alimentary Tract KEY
WORDS:
Extramedullary hematopoiesis, presacral mass, b-thalassemia intermedia
Presacral (retrorectal) tumors are particularly rare in the adult. They usually present with vague symptoms and are a diagnostic challenge due to difficulty in the performance of diagnostic biopsy and the need for specialized imaging required to plan surgical extirpation.1 Traditionally, these masses are classified as cystic or solid lesions. Most cystic lesions are developmental cysts (mainly dermoid and epidermoid cysts, tailgut cysts, and cystic hamartomas),1 and the majority of the solid lesions are neoplasms (mainly chordomas).1,2 We, herein, present a patient with a symptomatic, solid lesion that does not fall into any of these categories. CASE REPORT A 48-year-old female presented to our institution complaining of painful defecation that had been bothering her for the last 3 months. There was no history of weight loss or change in bowel habits. She was diagnosed with b-thalassemia intermedia at 8 years of age, has never been in need of blood transfusions, and was lost to follow-up during the last 10 years. Her physical examination was unremarkable except for an enlarged spleen. Rectal
digital examination revealed a tender posterior mass with a soft consistency and a smooth contour. Her laboratory workup was remarkable for a microcytic anemia with hemoglobin values of 9.7 g/dL, mean corpuscular volume (MCV) 63.7 fL, and platelets 90,000/mm3. A computed tomography scan showed a 3 3 3 3 5-cm smoothly marginated, solid, presacral mass. No abnormal lymph nodes were detected. Hepatosplenomegaly was also present. As part of the preoperative survey, magnetic resonance imaging was performed. The mass showed a high-signal intensity on T1 and T2 weight images (Fig. 1), and was uniformly enhanced after gadolinium injection. Due to the unclear nature of the mass, a diagnostic excision was performed. A posterior approach was used to reach the presacral space. The mass was encapsulated by soft, smooth fibrotic tissue and was firmly adherent to the posterior wall of the rectum, without evidence of invasion. The mass was extirpated as a whole (Fig 2). The pathologic examination of the mass showed fatty connective tissue interspaced with bone marrow trabeculae and hyperplastic hematopoietic cells (Fig 3), all consistent with a diagnosis of extramedullary hematopoiesis (EH).
From the Department of Surgery, Western Galilee Medical Center, Nahariya, Israel. No financial support has been granted for the work described in this article and no involvement exists with any organization with an interest in the subject matter. Reprint requests: Dr. Ilan Youngster, Western Galilee Medical Center, Dept. of Surgery, 23 Nes-ziona 74077, Israel. e-mail: ilanyoungster@ yahoo.com Ó 2006 The Society for Surgery of the Alimentary Tract Published by Elsevier Inc.
1091-255X/06/$dsee front matter doi:10.1016/j.gassur.2005.05.010
927
928
Youngster et al.
Journal of Gastrointestinal Surgery
Fig. 3. Microscopic examination of the mass revealing hyperplastic hematopoietic tissue. Fig. 1. Magnetic resonance imaging of the abdomen and pelvis: sagital view. A clearly demarcated presacral mass is shown.
The postoperative course was uneventful. The patient was discharged on the fourth postoperative day. On subsequent follow-up 12 months later, the patient was completely asymptomatic.
DISCUSSION EH is the development and growth of hematopoietic tissue outside of the bone marrow. After birth, it is considered abnormal and is usually a compensatory phenomenon in diseases of reduced erythrocyte production or accelerated erythrocyte destruction.3 The most commonly associated conditions are myelofibrosis with myeloid metaplasia, and thalassemia
Fig. 2. Specimen after surgical extraction.
(mainly b-thalassemia intermedia).3 The liver and spleen are the most common sites involved in pathologic EH. However, the process has been described in various other sites, especially the intrathoracic paravertebral location.3,4,5 In a retrospective chart review by Cody et al.3 of 510 cases involving EH, only 27 (5.3%) were nonhepatosplenic. Of these 27 cases, 7 (26%) were paravertebral, and the rest involved various lymph nodes (15%), retroperitoneum (15%), pleura (11%), and other less common sites. The presacral space is a particularly rare site of EH, and to date only a few other cases have been described in English literature.3–8 Clinically, EH may present as an incidental finding or with local symptoms and signs of a mass effect. The radiographic appearance of EH has been described previously in various studies, but is generally nondiagnostic. CT scan shows a heterogeneous lobulated soft tissue density mass with a sharp demarcation.4 Magnetic resonance imaging (MRI) usually demonstrates a high-signal intensity on T1 and T2 weighted images.4,7 Other diagnostic modalities include 99mTc sulfur colloid bone marrow scan and angiography.3,7 The management of these lesions is influenced by the symptoms. Asymptomatic masses can be observed safely without surgical intervention. Symptomatic masses require treatment. Ectopic hematopoietic tissue has been shown to be extremely sensitive to low doses of radiation. Koch et al. showed a 71% response rate to a radiation dose of 4.25 Gy delivered in 10 fractions.3 In our case the management was influenced by the symptoms and the unusual site of growthdthe presacral space. Although at least half of the presacral tumors presenting in the adult are asymptomatic, and the majority are benign, it is generally recommended that these lesions be removed.1 The role
Vol. 10, No. 6 2006
of preoperative biopsy is controversial. Biopsy can be followed by serious and even fatal complications, including infections and bleeding from damage to the middle sacral artery.1 Wolpert et al. recommended that preoperative biopsy be done only in solid lesions with signs of malignancy such as sacral invasion.1 If a presacral needle biopsy is decided upon, it must be done in such a way that the needle tract can be excised en bloc with the tumor should operative excision be subsequently performed.1,4 In patients suffering from chronic blood dyscrasias, the possibility of EH should be taken into account during initial evaluation of space-occupying lesions. The presence of symptoms dictates the proper management, which can consist of radiographic follow-up only, radiation treatment, or surgical excision. In our case the unusual site of growth, combined with the fact that the patient was symptomatic, made us choose the surgical option.
Presacral Extramedullary Hematopoiesis
929
REFERENCES 1. Wolpert A, Beer-Gabel M, Lifschitz O, et al. The management of presacral masses in the adult. Tech Coloproctol 2002;6:43–49. 2. Stewart RJ, Humphreys WG, Parks TG. The presentation and management of presacral tumors. Br J Surg 1986;73: 153–155. 3. Koch A, Li C-Y, Mesa R, et al. Nonhepatosplenic extramedullary hematopoiesis: Associated diseases, pathology, clinical course, and treatment. Mayo Clin Proc. 2003;78:1223–1233. 4. Miyake H, Matsuda M, Iyomasa S, et al. Presacral extramedullary hematopoiesis. Surgery 2004;135:112–113. 5. Sarmiento M, Wolff BG. A different type of presacral tumor: Extramedullary hematopoiesis. Dis Colon Rectum 2003;46: 683–685. 6. Newton KL, McNeeley G, Novick M. Extramedullary hematopoiesis presenting as a pelvic mass in a patient with b-thalassemia intermidia. JAMA 1983;250:2178–2179. 7. Karak P, Shoukri KC, Spencer RP, et al. Presacral hematopoietic tissue: correlation of radionuclide and MRI findings. Clin Nucl Med 1998;23:330–331. 8. Gemenis T, Philippou A, Gouliamos A, et al. Atypical location of extramedullary hematopoietic masses in thalassemia. Radiologe 1989;29:295–296.