Exceptional localization of extramedullary hematopoiesis: presacral and periureteral masses

Extramedullary Hematopoiesis in Mismatch Repair Deficient Colon Cancer Patient on Adjuvant Chemotherapy

A 59-year-old male presented with a two-month history of abdominal pain and was found to have an obstructing cecal mass. Colonoscopy and biopsy confirmed invasive adenocarcinoma. Immunohistochemical analyses for mismatch repair (MMR) proteins revealed the loss of MLH1 as well as PMS2 in cancerous nuclei, which makes the tumor MMR deficient. Negative germline testing for MMR proteins ruled out the Lynch syndrome. After negative staging computerized tomography scan for distant metastases, he underwent ileocolectomy with ileotransverse colonic anastomosis. Final pathological analysis revealed poorly differentiated adenocarcinoma with signet ring features, negative margins, and 3/22 lymph nodes positive, classified as stage IIIB (T4aN1bM0). Adjuvant chemotherapy with modified FOLFOX (leucovorin calcium/folinic acid, fluorouracil, and oxaliplatin) was started without the use of any growth factor support. After cycle 9 of 12, he developed mild transaminitis, carcinoembryonic antigen elevation, and interval development of two heterogeneously enhancing hepatic lesions. Biopsy of both of these lesions revealed extramedullary hematopoiesis (EMH), with no evidence of metastatic disease. He completed adjuvant chemotherapy without complication, and these liver lesions have decreased in size during the follow-up period of almost two years thus far.

EMH is extremely rare in patients with colon cancer. Contributing factors include therapy-specific (growth factor support), bone marrow suppression secondary to chemotherapy and radiation therapy, and tumor-specific factors (cytokine and growth factors released by the tumor). To the best of our knowledge, this is the first case report of EMH in an MMR deficient colon cancer patient on adjuvant FOLFOX. MMR-deficient tumors show signs of a high degree of infiltration with CD8+ cytotoxic T lymphocytes as well as helper T cells, leading to increased production of cytokines, such as interferon-γ. This could be a potential etiology behind EMH in our patient who was MMR deficient. The role of the MMR-deficient state in the development of EMH should be explored further.

Rare case of focal mass like perirenal extramedullary haematopoiesis in a renal transplant recipient

Extramedullary haematopoiesis (EMH) is a physiological process of formation of blood cells outside the bone marrow in response to insufficient production or excessive destruction of blood cells. Most common sites of EMH are liver, spleen, lymph nodes, kidney and paraspinal regions. In this report, we have described a rare case of focal EMH which presented as a mass adjacent to the renal allograft. Imaging characteristics favoured a benign aetiology with MRI signals suggesting the presence of blood and fatty components. The final diagnosis of EMH was made by aspiration cytology and an unnecessary surgery was thus avoided.

Intracranial Hematopoiesis in Beta Thalassemia: A Case Series

Extramedullary hematopoiesis (EMH) is a normal response to failure of hematopoiesis at its normal site i.e., bone marrow. It is a manifestation of many congenital hemolytic anemias and marrow failure secondary to myelodysplastic syndromes. Usually, extramedullary myeloid proliferation occurs in liver, spleen and lymph nodes. However, there are many unusual sites where EMH can occur. The authors report two cases of intracranial extramedullary hematopoiesis in beta thalassemia. In one of these patients, epidural soft tissue was detected along frontal and parietal convexities causing compression of brain parenchyma leading to raised intracranial tension and sagging of brain stem, corpus callosum and herniation of cerebellar tonsils. The other case had a similar but unilateral epidural soft tissue. Expansion of diploic spaces of skull was seen in both these cases. As myeloid proliferation is slow, it presents with subtle symptoms of headache and gradually progressive lower limb weakness. A high index of clinical suspicion coupled with imaging findings is the only way to confirm the diagnosis.

Extramedullary hematopoiesis secondary to malignant solid tumors: a case report and literature review

Extramedullary hematopoiesis (EMH) usually occurs in hematological disease, but more rarely develops in cases of malignant solid tumors. Due to its features on computed tomography (CT) and magnetic resonance imaging (MRI) that are atypical, EMH in tumor patients might easily be misdiagnosed as metastasis leading to the improper TNM staging and inappropriate therapy. Here, we reported the first case of pleural EMH occurring in a patient with esophageal carcinoma whose pleural lesion was first diagnosed as metastasis and confirmed EMH after the needle biopsy. In addition, a retrospective review was conducted by analyzing patients presented with EMH with malignant solid tumors from PubMed and Medline databases. A total of 42 solid tumor patients with EMH were enrolled, and breast cancer was the most common (n=13, 31.0%), followed by renal carcinoma (n=7, 16.7%) and lung cancer (n=6, 14.3%). A wide variety of body sites may be affected by EMH in malignant solid tumor patients, of which the lymph nodes (n=8, 19.0%) and liver (n=7, 16.7%) were the most common, followed by the kidney (n=6, 14.3%). All patients were diagnosed with EMH by excision, biopsy, or autopsy. Treatment strategies for EMH included surgery (n=25, 59.5%), hydroxyurea (n=1, 2.4%), and blood transfusions (n=2, 4.8%); a further 14 patients (33.3%) were subjected to clinical observation without intervention. Of the patients for whom outcome was reported, 10 patients maintained a good performance status (23.8%) and a further six patients died from the malignant tumor. This was the first study to summarize the presentations of EMH in malignant solid tumors, and our findings might provide some useful guidance for clinical practice, especially for treating patients harboring nonresponse lesions during the antitumor treatment.

The bottom line: MRI and CT findings of unusual rectal and perirectal pathology

Although common nonspecific symptoms (i.e., rectal bleeding, pelvic pressure, and change in bowel habits) are associated with rectal cancer, occasionally these are related to a different underlying disease. Over the past few years, considerable progress has been made in imaging of the rectum. Specifically, new magnetic resonance techniques and capabilities provide impressive high-resolution assessment of the rectal wall and enable evaluation and characterization of the perirectal tissues. This paper reviews imaging findings of uncommon causes of rectal and perirectal pathology that may be clinically confounded with rectal cancer. Radiologists need to be aware of uncommon pathologies in this region in order to facilitate optimal management decisions.

A systematic review of presacral extramedullary haematopoiesis: a diagnosis to be considered for presacral masses

AIM

Presacral masses are uncommon and have malignant potential; treatment typically includes surgical excision. However, there are conditions such as extramedullary haematopoiesis (EMH) which are benign. The present study aimed to summarize the presentation of presacral EMH in our institution, to review the literature and to offer management strategies for this rare condition.

METHOD

The literature was searched for articles related to presacral EMH, and case reports were collected from articles meeting the inclusion criteria. We collected data on patient demographics, diagnostic investigation, management and the results of treatment.

RESULTS

Thirty-nine patients were included in the systematic review. Initial imaging included computed tomography (CT), magnetic resonance imaging (MRI) or ultrasound (US) suggestive of EMH. Some patients then underwent a technetium scan (n = 7, 18%), biopsy of the presacral lesion (n = 27, 69%) or excision of the entire mass (n = 3, 8%). All patients who underwent technetium scan were confirmed to have EMH, demonstrating enhancement similar to bone marrow. Patients who underwent technetium scan and presacral mass biopsy had concordant results confirming presacral EMH (n = 5, 13%). Data on management were available for 35/39 (90%) with most patients followed by clinical observation (n = 20, 51%). Symptomatic patients were treated with radiotherapy (15%), surgical excision (15%) or hydroxyurea (5%) and blood transfusions (10%). Most (81%, n = 17/21) patients whose outcome was reported remained asymptomatic or experienced pain relief.

CONCLUSION

Although uncommon, EMH should be considered in the differential diagnosis of a presacral mass. Presacral EMH is a benign condition that can be suspected on CT or MRI and confirmed with technetium scan. Patients may not necessarily need to undergo biopsy to confirm haematopoietic elements. Unlike other presacral masses, patients diagnosed with presacral EMH can be managed by observation. If symptomatic, radiotherapy or surgical excision may be offered.

Extramedullary Hematopoiesis: Cytomorphologic, Histologic, and Radiologic Findings in Sixteen Cases

BACKGROUND

We report a case series of extramedullary hematopoiesis (EMH) diagnosed from the fine needle aspiration (FNA) procedure. Unanticipated EMH is a markedly rare diagnosis that typically presents as a solitary mass of undetermined significance. As such, knowledge of cytopathologic characteristics as well as clinical and radiologic correlates of EMH is paramount.

METHOD AND MATERIAL

A total of 16 EMH cytopathologic cases were seen at the Johns Hopkins Hospital in the past 22 years.

RESULTS

Median age at diagnosis was 61 years and there was no gender bias (male-to-female ratio: 1:1). Presenting signs and symptoms varied widely, from incidental radiographic findings to hemiparesis. Likewise, presumptive clinical diagnoses in 11 of the 16 cases were benign and the other 5 were considered malignant prior to the diagnostic FNA. The most common anatomic site for EMH was the liver, followed by the presacral soft tissue and pleura. While most EMH nodules were singular, a few presented with as many as three radiographically distinct nodules. The average EMH nodule measured 2.8 cm; the EMH liver nodules were larger and measured 4.3 cm on average (p = 0.0043).

CONCLUSION

We share here the salient clinical and radiologic findings and the diagnostic cytopathologic features of EMH in an effort to familiarize the pathologist/cytotechnologist community with this fascinating albeit rare entity.

Presacral extramedullary hematopoiesis: an alternative hypothesis

Idiopathic extramedullary hematopoiesis (EMH) is the production of blood cells outside of the bone marrow without an underlying hematological pathology. This article examines the rare case of idiopathic EMH in the presacral area. A 65-year-old woman with a past medical history of a total abdominal hysterectomy and a negative hematological history presented with back and leg pain. MRI revealed a presacral mass. Fine needle aspiration revealed a diagnosis of EMH. The patient was managed conservatively with serial imaging. We present this patient with rare idiopathic, presacral EMH and review the literature on this topic. The current pathophysiology suggests that sacral fractures release hematopoietic stem cells, which in turn replicate to form an EMH mass. This review suggests a second mechanism in which surgical manipulation of the uterine tissue releases mesenchymal stem cells. These cells differentiate into stromal tissue that interacts with multipotent hematopoietic stem cells in order to form an EMH mass. Thus, idiopathic, presacral EMH may develop from either bone fractures or surgical manipulation of the uterus. Management of these patients should include watchful waiting unless intractable pain, new-onset weakness, or bowel/bladder dysfunction develops.

Ectopic extramedullary hematopoiesis: evaluation and treatment of a rare and benign paraspinal/epidural tumor

Ectopic extramedullary hematopoiesis (EMH), defined as the formation of blood cells outside the bone marrow, usually occurs in a scenario of chronic anemia when, even after conversion of the bony yellow marrow to red marrow, the body is still unable to meet the demand for red blood cells. Ectopic extramedullary hematopoiesis most commonly occurs in the liver and spleen but may, in fact, occur almost anywhere in the body. Although previous reports have documented EMH presenting as paraspinal masses, such lesions have almost always been associated with a predisposing hematological disorder such as hemolytic anemia, myelofibrosis or myelodysplastic syndromes, thalassemia, polycythemia vera, leukemia, or lymphoma.

The authors of this report describe the first reported instance of EMH in a patient presenting with a symptomatic epidural and paraspinal cervical lesion arising from the posterior spinal elements and no known predisposing hematological disease. Initial radiographs revealed a bony lesion arising posteriorly from the C2–3 laminae and spinous processes. Subsequent imaging suggested the diagnosis, which was confirmed by CT-guided biopsy, peripheral blood smears, and bone marrow aspirate. Despite epidural compression and slight displacement of the cervical cord and thecal sac, the patient's symptoms were limited to pain and diminished cervical range of motion. Therefore, surgery was deferred in favor of nonsurgical therapy. Several alternative modalities for the treatment of EMH have been suggested in the literature, including cytotoxic agents and radiotherapy. The authors opted for an approach utilizing directed low-dose radiotherapy of a total of 25 Gy divided in 2.5-Gy fractions. At the 3-month follow-up, the patient continued to be asymptomatic, and MRI demonstrated a significant reduction in the dimensions of the lesion.

Extramedullary hematopoiesis with spinal cord compression in the absence of a preexisting hematological disorder has not been described in the context of clinical neurosurgical practice. Recognizing that EMH may present as an epidural or paraspinal lesion is important since chemotherapy and radiotherapy are effective therapeutic options in the majority of patients who suffer few if any symptoms. Extensive evaluation for underlying hematological disorders is necessary before undertaking directed therapy. Inadvertent resection of these highly vascularized masses may risk catastrophic intraoperative hemorrhage with no proven benefit as compared with medical treatment, which usually provides excellent long-term outcomes.

Mass-like extramedullary hematopoiesis: imaging features

PURPOSE

To report the imaging appearances of mass-like extramedullary hematopoiesis (EMH), to identify those features that are sufficiently characteristic to allow a confident diagnosis, and to recognize the clinical conditions associated with EMH and the relative incidence of mass-like disease.

MATERIALS AND METHODS

We retrospectively identified 44 patients with EMH; 12 of which (27%) had focal mass-like lesions and formed the study group. The study group consisted of 6 male and 6 female subjects with a mean age of 58 years (range 13-80 years). All 12 patients underwent CT imaging and 3 of the 12 patients had undergone additional MR imaging. The imaging characteristics of the extramedullary hematopoiesis lesions in the study group were analyzed and recorded. The patient's clinical presentation, including any condition associated with extramedullary hematopoiesis, was also recorded.

RESULTS

Ten of the 12 (83%) patients had one or more masses located along the axial skeleton. Of the 10 patients with axial masses, 9 (90%) had multiple masses and 7 (70%) demonstrated internal fat. Eight patients (80%) had paraspinal masses and 4 patients (40%) had presacral masses. Seven patients (70%) had splenomegaly. Eleven of the 12 patients had a clinical history available for review. A predisposing condition for extramedullary hematopoiesis was present in 10 patients and included various anemias (5 cases; 45%), myelofibrosis/myelodysplastic syndrome (4 cases; 36%), and marrow proliferative disorder (1 case; 9%). One patient had no known predisposing condition.

CONCLUSION

Mass-like extramedullary hematopoiesis most commonly presents as multiple, fat-containing lesions localized to the axial skeleton. When these imaging features are identified, extramedullary hematopoiesis should be strongly considered, particularly when occurring in the setting of a predisposing medical condition.

Post-traumatic pelvic extramedullary haemopoetic tissue causing lower urinary tract symptoms

Extramedullary haemopoiesis (EMH) is the abnormal development and growth of haemopoietic tissue outside the bone marrow. It is usually asymptomatic and occurs in the presence of myelodysplastic syndromes. In this report, we describe the first post-traumatic EMH presenting with lower urinary tract symptoms.

Presacral extramedullary haematopoiesis: A diagnostic update and case report of a late diagnosis

INTRODUCTION

We report a rare case of presacral extramedullary haematopoiesis, which manifested as a tumoural mass on a routine ultrasonography in a patient presenting with symptoms of cholecystitis. Since Ask-Upmark in 1945 reported 3 cases of pelvic extramedullary haematopoiesis, we are aware of only published 14 additional cases.

PRESENTATION OF CASE

A 73-year-old female patient presented with abdominal pain in the right hypochondrium. An abdominal ultrasonography revealed cholecystitis with cholecystolithiasis and a coincidental hyperreflective mass of 9.5cm was visualised behind the bladder. A clinical examination identified a mass in the pelvis that could be palpated vaginally. A computerised tomography scan showed a large presacral, inhomogeneous, multilobular and nodular tumour. The patient was admitted for laparoscopic resection of the gall bladder and laparoscopic exploration of the presacral mass. An anatomopathological examination of the tissue revealed the presence of extramedullary haematopoietic tissue. A postoperative haematological investigation indicated that the extramedullary haematopoiesis was idiopathic.

DISCUSSION

Presacral EMH may occasionally present with symptoms of nerve compression. Symptoms of haematologic disorders may accompany EMH. Barium enema, abdominal ultrasound, CT scan, MRI and radionuclide bone marrow imaging have all been used by previous authors in establishing the diagnosis. Tissue samples may be misdiagnosed when atypical megakaryocytes are misinterpreted as malignant cells, which occurred in this case. Misdiagnosis can occur even more often when EMH is not considered in the differential diagnosis due to its rare occurrence. In this case, the final diagnosis was made tissue sampling after surgery. Treatment of EMH is only necessary when it is symptomatic.

CONCLUSION

This case report shows that extramedullary haematopoiesis is very rare and that it is a difficult diagnostic challenge when its location is unusual and when it is not associated with a haematologic disorder. Together with this case report, we present an update of the available diagnostic methods.

Extramedullary hematopoiesis in unusual locations in hematologically compromised and noncompromised patients

Extramedullary hematopoiesis (EMH) occurs as a compensatory reaction to an underlying hematologic abnormality. EMH is most commonly seen in the liver and spleen but rarely has been reported in other locations, as well. On rare occasions, EMH may mimic a neoplasm in hematologically noncompromised patients. In this report, we present three cases of EMH in unusual locations, two in the presacral soft tissue and one in the synovial lining of the knee joint. The patients with presacral masses had no hematologic abnormality. In all patients with EMH, imaging plays an important role in both localization of the lesion and guidance for the biopsy; when imaging results are correlated with histological findings, the diagnosis of EMH can be confirmed.

Extramedullary hemopoiesis with undiagnosed, early myelofibrosis causing spastic compressive myelopathy: Case report and review

Extramedullary hemopoiesis (EMH) is a common compensatory phenomenon associated with chronic hemolytic anemia. Abnormal hemopoietic tissue usually develops in sites responsible for fetal hemopoiesis, such as spleen, liver and kidney; however, other regions such as the spine may also become involved. In this study, a patient presenting with spastic paraparesis due to EMH in the dorsal spine is described. A 62-year-old man presented with paraparesis. Magnetic resonance imaging revealed a large lesion involving the T2-L2 vertebral levels with a large extradural component causing thecal sac compression. Laminectomy with excision of mass was carried out. The histopathology revealed EMH. The patient had no known cause for EMH at the time of diagnosis but, subsequently, a bone marrow examination revealed early myelofibrosis. This case represents the rare occurrence of a large extradural extramedullary hematopoiesis in a patient with no known predisposing factor for hemopoiesis at the time of presentation.

An interesting diagnosis for a presacral mass: case report

A presacral mass can present a diagnostic dilemma for the surgical oncologist. Differential diagnoses include congenital causes such as teratoma or chordoma, neurological causes such as neurilemoma or neurofibroma or other malignancies such as lymphoma or sarcoma. Diagnosis usually requires imaging such as CT and MRI and tissue biopsy. We present an unusual cause of a presacral mass being extramedullary haematopoiesis, found incidentally in a 71 year old female. Extramedullary haematopoiesis is defined as the production of myeloid and erythroid elements outside of the bone-marrow. This diagnosis is extremely rare in the presacral area especially in a patient with no haematological abnormalities. A review of the literature is presented.