Jpn J Radiol DOI 10.1007/s11604-014-0302-4
CASE REPORT
Crystal-storing histiocytosis associated with marginal-zone lymphoma Keiichiro Tahara • Kimitaka Miyajima Minoru Ono • Yasuhiro Sugio • Ichiro Yamamoto • Sadafumi Tamiya
•
Received: 17 October 2013 / Accepted: 26 February 2014 Ó Japan Radiological Society 2014
Abstract We report a rare case of crystal-storing histiocytosis (CSH) associated with marginal-zone lymphoma. A 91-year-old woman with a history of breast cancer presented with masses of the posterior neck, right breast, and left upper arm. An enlarging mass of the neck was removed and was histologically diagnosed as CSH, associated with marginal-zone lymphoma. Masses in the breast and upper arm were evaluated by needle biopsy and revealed as CSH. CSH is a rare condition characterized by the intrahistiocytic accumulation of crystallized immunoglobulins, and is associated with disorders in which monoclonal immunoglobulins are expressed. To the best of our knowledge, there are few previous descriptions of CSH which include the imaging features of this disease. In the present case, the masses showed hypoechogenicity with internal patchy hyperechoic areas on ultrasonography, and an iso-signal to slight hyperintensity compared with muscle on T2-weighted magnetic resonance imaging. We report the imaging findings in CSH and discuss their diagnostic implications.
K. Tahara M. Ono Department of Radiology, Kitakyushu Municipal Medical Center, 2-1-1 Bashaku, Kokurakita-ku, Kitakyushu, Japan K. Miyajima (&) Department of Radiology, National Hospital Organization Beppu Medical Center, 1473 Uchikamado, Beppu 874-0011, Japan e-mail: [email protected] Y. Sugio Department of Internal Medicine, Kitakyushu Municipal Medical Center, Kitakyushu, Japan I. Yamamoto S. Tamiya Department of Pathology, Kitakyushu Municipal Medical Center, Kitakyushu, Japan
Keywords Crystal-storing histiocytosis Marginal-zone lymphoma Ultrasonography Magnetic resonance imaging
Introduction Crystal-storing histiocytosis (CSH) is a rare condition arising from the accumulation of crystalline material in the cytoplasm of histiocytes. It is associated with disorders characterized by the expression of monoclonal immunoglobulins, such as multiple myeloma, lymphoplasmacytic lymphoma, and monoclonal gammopathy of undetermined significance (MGUS) [1]. Approximately 90 cases of CSH have been reported thus far. However, most of those reports focused on the pathological features of the disease, whereas its radiological characteristics, including those determined by ultrasonography (US) and magnetic resonance imaging (MRI), have rarely been described. Here, we present a case of CSH and describe the associated US and MRI findings as well as their diagnostic implications.
Case report A 91-year-old woman, who was followed up at our hospital after undergoing left breast resection because of breast cancer, complained of increasing induration involving the posterior neck. The neck mass was unmovable and hard. Physical examination revealed multiple palpable tumors in her right breast and left upper arm. No other abnormality was found on physical examination. Her peripheral blood count was normal. Serum protein analysis showed that total protein (7.7 g/dl, normal range 6.7–8.3) and albumin (4.3 g/dl, normal range 4.0–5.0) were normal, whereas A/G
123
Jpn J Radiol
Fig. 1 Mass in the posterior neck on US and MRI. a US revealed a hypoechoic mass with internal patchy hyperechoic areas (arrowheads). b Axial T1-weighted imaging (TR/TE 433.33/8.49) showed an oval mass with iso-signal intensity with muscle (arrows) and peripheral hyperintense foci, suggesting involvement of normal fat
tissue. c Axial T2-weighted imaging (TR/TE 3800.00/81.52) showed that the mass had low signal intensity (arrows). d Heterogeneous mild enhancement was seen on sagittal fat-saturated contrast-enhanced T1weighted imaging (TR/TE 433.33/8.82, arrow)
ratio (1.38, normal range 1.42–2.44) was slightly decreased and IgM (277 mg/dl, normal range 35–220) was slightly increased. There was no abnormality in C-reactive protein. US showed that the neck mass was hypoechoic with internal patchy hyperechoic areas (Fig. 1a). On MRI, T1weighted spin-echo and T2-weighted fast spin-echo images revealed an oval mass with low signal intensity. T1-weighted spin-echo images showed iso-signal intensity with the striated muscles (Fig. 1b). T2-weighted fast spin-echo images showed iso-signal to slightly increased signal intensity compared with the striated muscles. The mass was illdefined, with peripheral hyperintense foci, suggesting
involvement of normal fat tissue (Fig. 1c). On fat-saturated contrast-enhanced T1-weighted spin-echo imaging, the mass showed heterogeneous mild enhancement (Fig. 1d). At the upper outer quadrant of the right breast, US showed that hyperechoic and hypoechoic areas were intermingled irregularly (Fig. 2a). Fat-saturated T2-weighted MRI showed that the mass had low signal intensity. On fat-saturated contrastenhanced MRI (Volume Imaging Breast Assessment-Dual Echo: VIBRANT TR/TE 6.84/3.24), the mass showed heterogeneous enhancement, and the enhanced area spread to the subcutaneous tissue (Fig. 2b). The upper arm mass was hypoechoic with irregular hyperechoic areas on US
123
Jpn J Radiol
Fig. 2 Mass in the upper outer quadrant of the right breast on US and MRI. a US showed that hyperechoic and hypoechoic areas were intermingled irregularly (arrowheads). b An ill-defined mass with
heterogeneous enhancement was seen on the axial VIBRANT sequence (TR/TE 6.84/3.24) of fat-saturated contrast-enhanced T1weighted imaging (arrows)
Fig. 3 Mass in the left upper arm on US and MRI. a US showed a hypoechoic mass with internal hyperechoic areas (arrowheads). b Sagittal T2weighted imaging (TR/TE 2000.00/84.11) confirmed the hypointense mass (arrows). c Heterogeneous mild enhancement was seen on sagittal fat-saturated contrastenhanced T1-weighted imaging (TR/TE 416.66/11.98, arrows)
(Fig. 3a). On MRI, T1-weighted spin-echo and T2-weighted fast spin-echo images revealed an ill-defined oval mass with iso-signal intensity with the striated muscle (Fig. 3b). On fatsaturated contrast-enhanced T1-weighted spin-echo
imaging, the mass showed heterogeneous mild enhancement (Fig. 3c). These masses showed similar imaging findings. Needle biopsy of the neck mass suggested degenerated muscle and an inflammatory infiltrate but no distinct focus
123
Jpn J Radiol
Fig. 4 Hematoxylin and eosin staining. a The tumor consisted of a diffuse infiltrate of histiocytic cells and an infiltrate of lymphocytic and plasmacytic cells (thick arrow) to a lesser extent. A small amount of fat tissue was seen (thin arrows, 9100). b Large histiocytic cells
had small nuclei and abundant eosinophilic laminated crystals (short arrows, 9400). c An aggregate of lymphocytic and plasmacytic cells is seen (9400)
of malignancy. However, because of further enlargement of the mass and in accordance with the patient’s wishes, it was removed. Histologically, the tumor consisted mostly of a diffuse infiltrate of large histiocytic cells with small nuclei and abundant eosinophilic laminated crystals, and to a lesser extent, of a lymphoid aggregate and infiltrate of plasmacytic cells (Fig. 4). Immunohistochemically, the large histiocytic cells and infiltrating plasma cells showed a monoclonal reaction to IgG, IgM and j light chain. The histiocytes were also positive for CD68, and negative for IgA, IgD, k light chain, S100 protein, desmin, and smooth muscle actin. The lymphocytic cells were positive for CD20 and CD79a. A diagnosis of CSH associated with marginal-zone lymphoma with plasmacytic differentiation was considered. The needle biopsy specimens of the masses in her breast and upper arm also showed an infiltrate of large histiocytic cells with abundant eosinophilic laminated crystals. Re-evaluation of the needle biopsy specimen from the neck mass
revealed that the degenerated muscle was sheets of large histiocytes with abundant crystals. Immunoelectrophoresis demonstrated increased IgM j type monoclonal protein. Bone marrow biopsy showed that plasma cell numbers were within normal limits and no additional foci of CSH were detected in the marrow. Computed tomography (CT) of the chest, abdomen and pelvis revealed no abnormality and lymphadenopathy. The patient was asymptomatic and of advanced age; therefore, no treatment was recommended other than periodic followups. Two years after her diagnosis of CSH, the other masses of her right breast and upper arm slightly enlarged on US, but there was no significant change in her subjective symptoms or laboratory data.
123
Discussion CSH is a rare disease in which crystalline material accumulates within the cytoplasm of histiocytes. Approximately
Jpn J Radiol
90 cases have been reported in the past. Dogan et al. [1] reviewed 80 cases of CSH, which occurred almost equally frequently in men and women, with a mean age of &60 years. They subdivided CSH into localized and generalized types. The former commonly occurs in the head and neck region and chest, while the latter occurs in bone marrow, liver, lymph node and spleen. The majority of cases are asymptomatic. The crystals are most often of immunoglobulin origin and are associated with disorders characterized by monoclonal immunoglobulin expression, such as multiple myeloma, lymphoplasmacytic lymphoma, MGUS and, less frequently, marginal-zone lymphoma. Recently, the number of reports of CSH associated with marginal-zone lymphoma has increased [2]. The exact mechanism for crystal formation in CSH is not well understood, but the overproduction or impaired excretion of immunoglobulins has been proposed. Several reports have described the difficulties in diagnosing CSH. Histologically, the presence of rhomboid, dense, crystal-like material in linear accumulations within the cytoplasm of histiocytes results in confusion of these cells with striated muscle. Friedman et al. [3] reported a case of CSH of the posterior neck in which the patient was initially diagnosed with a benign tumor of striated muscle; either adult rhabdomyoma or rhabdomyomatous hamartoma. The biopsy specimen from our patient was also initially identified as degenerated striated muscle. Moreover, CSH sometimes masks an underlying lymphoproliferative or plasma cell disorder. Jones et al. [4] reported that in several patients with myeloma, histiocytosis in the marrow was so pervasive compared with the plasma cell component that the diagnosis of a storage disorder or hemophagocytic syndrome was considered. In our patient, US showed a hypoechoic mass with internal patchy hyperechoic areas. This may have included involvement of fat tissue, but the reason for increased echogenicity remains unknown. To the best of our knowledge, ours is the first US description of CSH. Only a few cases of CSH have been evaluated by MRI and CT. Kaminsky et al. [5] reported CSH of the brain, which showed moderate T2 signal intensity on MRI. Todd et al. [6] reported CSH of a lung nodule with irregular margins on CT. Rossi et al. [7] reported CSH of the pleura, which had a pleural plaque-like thickness. The latter two lesions demonstrated metabolic activity on [18]-fluoro-2deoxy-D-glucose positron emission tomography. In our case, the most striking feature was the marked hypointensity of the mass on T2-weighted fast spin-echo imaging. This imaging appearance likely resulted from the enhanced T2 relaxation of the accumulated immunoglobulins. In their report of the MRI findings of localized amyloidosis, Gean-Marton et al. [8] emphasized the enhanced T2 relaxation of the lesion, which they attributed to (1) static or slowly fluctuating internal magnetic fields arising from
adjacent amyloid protons held in relatively fixed positions within the b-pleated sheet, resulting in a quick phase dispersion; (2) chemical exchange and spin–spin interactions with adjacent water protons; and (3) diffusion in response to differences in diamagnetic susceptibility. Amyloidosis is defined by the presence of extracellular deposits of insoluble, fibrillar, proteinaceous material. Especially in primary (AL) amyloidosis, characterized by the deposition of monoclonal immunoglobulin light chain fragments, the imaging findings may be the same as in CSH. Similarly, the MRI appearance of light chain deposition disease may resemble that of CSH. Baur et al. [9] reported the occurrence of light chain deposition disease in a patient with multiple myeloma of the bone marrow. The T1- and T2-weighted spin-echo and short tau inversion recovery images revealed multiple small foci of low signal intensity. Li et al. [10] reported another case of low-grade B-cell lymphoma with abundant intracellular immunoglobulin accumulation. The tumor had developed in the patient’s shoulder and showed low signal intensity on T2-weighted images. Regarding enhanced imaging, we could not find any previous reports mentioning enhanced imaging. The masses in our case of CSH were mildly enhanced. In contrast, there are several reports of amyloidosis related to varying degrees of enhanced imaging. Therefore, we think that it is difficult to distinguish CSH and amyloidosis on radiological images. In conclusion, the imaging findings of our rare case of CSH demonstrated the ill-defined margins of the lesion and its relatively low signal intensity on T2-weighted images. These findings should raise CSH as a differential diagnosis. Acknowledgments We appreciate the assistance of Dr. Morishige Takeshita (Professor, Department of Pathology, Fukuoka University) in the histological diagnosis. Conflict of interest of interest.
The authors declare that they have no conflict
References 1. Dogan S, Barnes L, Cruz-Vetrano WP. Crystal-storing histiocytosis: report of a case, review of the literature (80 cases) and a proposed classification. Head Neck Pathol. 2012;6:111–20. 2. Kusakabe T, Watanabe K, Mori T, Iida T, Suzuki T. Crystalstoring histiocytosis associated with MALT lymphoma of ocular adnexa: a case report with review of literature. Virchows Arch. 2007;450:103–8. 3. Friedman MT, Molho L, Valderrame E, Kahn LB. Crystal-storing histiocytosis associated with a lymphoplasmacytic neoplasm mimicking adult rhabdomyoma; a case report and review of the literature. Arch Pathol Lab Med. 1996;20:1133–6. 4. Jones D, Bhatia VK, Krausz T, Pinkus GS. Crystal-storing histiocytosis: a disorder occurring in plasmacytic tumors expressing immunoglobulin kappa light chain. Hum Pathol. 1999;30:1441–8.
123
Jpn J Radiol 5. Kaminsky IA, Wang AM, Olsen J, Schechter S, Wilson J, Olson R. Central nervous system crystal-storing histiocytosis. AJNR. 2011;32(2):E26–8. 6. Todd WU, Drabick JJ, Benninghoff MG, Frauenhoffer EE, Zander DS. Pulmonary crystal-storing histiocytosis diagnosed by computed tomography-guided fine-needle aspiration. Diagn Cytopathol. 2010;38(4):274–8. 7. Rossi G, Morandi U, Nannini N, Fontana G, Pifferi M, Casali C. Crystal-storing histiocytosis presenting with pleural disease. Histopathology. 2010;56(3):403–5.
123
8. Gean-Marton AD, Kirsch CFE, Vezina LG, Weber AL. Focal amyloidosis of the head and neck: evaluation with CT and MR imaging. Radiology. 1991;181:521–5. 9. Baur A, Stabler A, Lamerz R, Bartl R, Reiser M. Light chain deposition disease in multiple myeloma: MR imaging feature correlated with histopathological findings. Skeletal Radiol. 1998;27:173–6. 10. Li ZS, Li PF, Wang Z, Huang GS. Primary extranodal soft-tissue B-cell lymphoma with abundant immunoglobulin inclusions mimicking adult rhabdomyoma: a case report. J Med Case Rep. 2011;7(5):53.
CASE REPORT
Crystal-storing histiocytosis associated with marginal-zone lymphoma Keiichiro Tahara • Kimitaka Miyajima Minoru Ono • Yasuhiro Sugio • Ichiro Yamamoto • Sadafumi Tamiya
•
Received: 17 October 2013 / Accepted: 26 February 2014 Ó Japan Radiological Society 2014
Abstract We report a rare case of crystal-storing histiocytosis (CSH) associated with marginal-zone lymphoma. A 91-year-old woman with a history of breast cancer presented with masses of the posterior neck, right breast, and left upper arm. An enlarging mass of the neck was removed and was histologically diagnosed as CSH, associated with marginal-zone lymphoma. Masses in the breast and upper arm were evaluated by needle biopsy and revealed as CSH. CSH is a rare condition characterized by the intrahistiocytic accumulation of crystallized immunoglobulins, and is associated with disorders in which monoclonal immunoglobulins are expressed. To the best of our knowledge, there are few previous descriptions of CSH which include the imaging features of this disease. In the present case, the masses showed hypoechogenicity with internal patchy hyperechoic areas on ultrasonography, and an iso-signal to slight hyperintensity compared with muscle on T2-weighted magnetic resonance imaging. We report the imaging findings in CSH and discuss their diagnostic implications.
K. Tahara M. Ono Department of Radiology, Kitakyushu Municipal Medical Center, 2-1-1 Bashaku, Kokurakita-ku, Kitakyushu, Japan K. Miyajima (&) Department of Radiology, National Hospital Organization Beppu Medical Center, 1473 Uchikamado, Beppu 874-0011, Japan e-mail: [email protected] Y. Sugio Department of Internal Medicine, Kitakyushu Municipal Medical Center, Kitakyushu, Japan I. Yamamoto S. Tamiya Department of Pathology, Kitakyushu Municipal Medical Center, Kitakyushu, Japan
Keywords Crystal-storing histiocytosis Marginal-zone lymphoma Ultrasonography Magnetic resonance imaging
Introduction Crystal-storing histiocytosis (CSH) is a rare condition arising from the accumulation of crystalline material in the cytoplasm of histiocytes. It is associated with disorders characterized by the expression of monoclonal immunoglobulins, such as multiple myeloma, lymphoplasmacytic lymphoma, and monoclonal gammopathy of undetermined significance (MGUS) [1]. Approximately 90 cases of CSH have been reported thus far. However, most of those reports focused on the pathological features of the disease, whereas its radiological characteristics, including those determined by ultrasonography (US) and magnetic resonance imaging (MRI), have rarely been described. Here, we present a case of CSH and describe the associated US and MRI findings as well as their diagnostic implications.
Case report A 91-year-old woman, who was followed up at our hospital after undergoing left breast resection because of breast cancer, complained of increasing induration involving the posterior neck. The neck mass was unmovable and hard. Physical examination revealed multiple palpable tumors in her right breast and left upper arm. No other abnormality was found on physical examination. Her peripheral blood count was normal. Serum protein analysis showed that total protein (7.7 g/dl, normal range 6.7–8.3) and albumin (4.3 g/dl, normal range 4.0–5.0) were normal, whereas A/G
123
Jpn J Radiol
Fig. 1 Mass in the posterior neck on US and MRI. a US revealed a hypoechoic mass with internal patchy hyperechoic areas (arrowheads). b Axial T1-weighted imaging (TR/TE 433.33/8.49) showed an oval mass with iso-signal intensity with muscle (arrows) and peripheral hyperintense foci, suggesting involvement of normal fat
tissue. c Axial T2-weighted imaging (TR/TE 3800.00/81.52) showed that the mass had low signal intensity (arrows). d Heterogeneous mild enhancement was seen on sagittal fat-saturated contrast-enhanced T1weighted imaging (TR/TE 433.33/8.82, arrow)
ratio (1.38, normal range 1.42–2.44) was slightly decreased and IgM (277 mg/dl, normal range 35–220) was slightly increased. There was no abnormality in C-reactive protein. US showed that the neck mass was hypoechoic with internal patchy hyperechoic areas (Fig. 1a). On MRI, T1weighted spin-echo and T2-weighted fast spin-echo images revealed an oval mass with low signal intensity. T1-weighted spin-echo images showed iso-signal intensity with the striated muscles (Fig. 1b). T2-weighted fast spin-echo images showed iso-signal to slightly increased signal intensity compared with the striated muscles. The mass was illdefined, with peripheral hyperintense foci, suggesting
involvement of normal fat tissue (Fig. 1c). On fat-saturated contrast-enhanced T1-weighted spin-echo imaging, the mass showed heterogeneous mild enhancement (Fig. 1d). At the upper outer quadrant of the right breast, US showed that hyperechoic and hypoechoic areas were intermingled irregularly (Fig. 2a). Fat-saturated T2-weighted MRI showed that the mass had low signal intensity. On fat-saturated contrastenhanced MRI (Volume Imaging Breast Assessment-Dual Echo: VIBRANT TR/TE 6.84/3.24), the mass showed heterogeneous enhancement, and the enhanced area spread to the subcutaneous tissue (Fig. 2b). The upper arm mass was hypoechoic with irregular hyperechoic areas on US
123
Jpn J Radiol
Fig. 2 Mass in the upper outer quadrant of the right breast on US and MRI. a US showed that hyperechoic and hypoechoic areas were intermingled irregularly (arrowheads). b An ill-defined mass with
heterogeneous enhancement was seen on the axial VIBRANT sequence (TR/TE 6.84/3.24) of fat-saturated contrast-enhanced T1weighted imaging (arrows)
Fig. 3 Mass in the left upper arm on US and MRI. a US showed a hypoechoic mass with internal hyperechoic areas (arrowheads). b Sagittal T2weighted imaging (TR/TE 2000.00/84.11) confirmed the hypointense mass (arrows). c Heterogeneous mild enhancement was seen on sagittal fat-saturated contrastenhanced T1-weighted imaging (TR/TE 416.66/11.98, arrows)
(Fig. 3a). On MRI, T1-weighted spin-echo and T2-weighted fast spin-echo images revealed an ill-defined oval mass with iso-signal intensity with the striated muscle (Fig. 3b). On fatsaturated contrast-enhanced T1-weighted spin-echo
imaging, the mass showed heterogeneous mild enhancement (Fig. 3c). These masses showed similar imaging findings. Needle biopsy of the neck mass suggested degenerated muscle and an inflammatory infiltrate but no distinct focus
123
Jpn J Radiol
Fig. 4 Hematoxylin and eosin staining. a The tumor consisted of a diffuse infiltrate of histiocytic cells and an infiltrate of lymphocytic and plasmacytic cells (thick arrow) to a lesser extent. A small amount of fat tissue was seen (thin arrows, 9100). b Large histiocytic cells
had small nuclei and abundant eosinophilic laminated crystals (short arrows, 9400). c An aggregate of lymphocytic and plasmacytic cells is seen (9400)
of malignancy. However, because of further enlargement of the mass and in accordance with the patient’s wishes, it was removed. Histologically, the tumor consisted mostly of a diffuse infiltrate of large histiocytic cells with small nuclei and abundant eosinophilic laminated crystals, and to a lesser extent, of a lymphoid aggregate and infiltrate of plasmacytic cells (Fig. 4). Immunohistochemically, the large histiocytic cells and infiltrating plasma cells showed a monoclonal reaction to IgG, IgM and j light chain. The histiocytes were also positive for CD68, and negative for IgA, IgD, k light chain, S100 protein, desmin, and smooth muscle actin. The lymphocytic cells were positive for CD20 and CD79a. A diagnosis of CSH associated with marginal-zone lymphoma with plasmacytic differentiation was considered. The needle biopsy specimens of the masses in her breast and upper arm also showed an infiltrate of large histiocytic cells with abundant eosinophilic laminated crystals. Re-evaluation of the needle biopsy specimen from the neck mass
revealed that the degenerated muscle was sheets of large histiocytes with abundant crystals. Immunoelectrophoresis demonstrated increased IgM j type monoclonal protein. Bone marrow biopsy showed that plasma cell numbers were within normal limits and no additional foci of CSH were detected in the marrow. Computed tomography (CT) of the chest, abdomen and pelvis revealed no abnormality and lymphadenopathy. The patient was asymptomatic and of advanced age; therefore, no treatment was recommended other than periodic followups. Two years after her diagnosis of CSH, the other masses of her right breast and upper arm slightly enlarged on US, but there was no significant change in her subjective symptoms or laboratory data.
123
Discussion CSH is a rare disease in which crystalline material accumulates within the cytoplasm of histiocytes. Approximately
Jpn J Radiol
90 cases have been reported in the past. Dogan et al. [1] reviewed 80 cases of CSH, which occurred almost equally frequently in men and women, with a mean age of &60 years. They subdivided CSH into localized and generalized types. The former commonly occurs in the head and neck region and chest, while the latter occurs in bone marrow, liver, lymph node and spleen. The majority of cases are asymptomatic. The crystals are most often of immunoglobulin origin and are associated with disorders characterized by monoclonal immunoglobulin expression, such as multiple myeloma, lymphoplasmacytic lymphoma, MGUS and, less frequently, marginal-zone lymphoma. Recently, the number of reports of CSH associated with marginal-zone lymphoma has increased [2]. The exact mechanism for crystal formation in CSH is not well understood, but the overproduction or impaired excretion of immunoglobulins has been proposed. Several reports have described the difficulties in diagnosing CSH. Histologically, the presence of rhomboid, dense, crystal-like material in linear accumulations within the cytoplasm of histiocytes results in confusion of these cells with striated muscle. Friedman et al. [3] reported a case of CSH of the posterior neck in which the patient was initially diagnosed with a benign tumor of striated muscle; either adult rhabdomyoma or rhabdomyomatous hamartoma. The biopsy specimen from our patient was also initially identified as degenerated striated muscle. Moreover, CSH sometimes masks an underlying lymphoproliferative or plasma cell disorder. Jones et al. [4] reported that in several patients with myeloma, histiocytosis in the marrow was so pervasive compared with the plasma cell component that the diagnosis of a storage disorder or hemophagocytic syndrome was considered. In our patient, US showed a hypoechoic mass with internal patchy hyperechoic areas. This may have included involvement of fat tissue, but the reason for increased echogenicity remains unknown. To the best of our knowledge, ours is the first US description of CSH. Only a few cases of CSH have been evaluated by MRI and CT. Kaminsky et al. [5] reported CSH of the brain, which showed moderate T2 signal intensity on MRI. Todd et al. [6] reported CSH of a lung nodule with irregular margins on CT. Rossi et al. [7] reported CSH of the pleura, which had a pleural plaque-like thickness. The latter two lesions demonstrated metabolic activity on [18]-fluoro-2deoxy-D-glucose positron emission tomography. In our case, the most striking feature was the marked hypointensity of the mass on T2-weighted fast spin-echo imaging. This imaging appearance likely resulted from the enhanced T2 relaxation of the accumulated immunoglobulins. In their report of the MRI findings of localized amyloidosis, Gean-Marton et al. [8] emphasized the enhanced T2 relaxation of the lesion, which they attributed to (1) static or slowly fluctuating internal magnetic fields arising from
adjacent amyloid protons held in relatively fixed positions within the b-pleated sheet, resulting in a quick phase dispersion; (2) chemical exchange and spin–spin interactions with adjacent water protons; and (3) diffusion in response to differences in diamagnetic susceptibility. Amyloidosis is defined by the presence of extracellular deposits of insoluble, fibrillar, proteinaceous material. Especially in primary (AL) amyloidosis, characterized by the deposition of monoclonal immunoglobulin light chain fragments, the imaging findings may be the same as in CSH. Similarly, the MRI appearance of light chain deposition disease may resemble that of CSH. Baur et al. [9] reported the occurrence of light chain deposition disease in a patient with multiple myeloma of the bone marrow. The T1- and T2-weighted spin-echo and short tau inversion recovery images revealed multiple small foci of low signal intensity. Li et al. [10] reported another case of low-grade B-cell lymphoma with abundant intracellular immunoglobulin accumulation. The tumor had developed in the patient’s shoulder and showed low signal intensity on T2-weighted images. Regarding enhanced imaging, we could not find any previous reports mentioning enhanced imaging. The masses in our case of CSH were mildly enhanced. In contrast, there are several reports of amyloidosis related to varying degrees of enhanced imaging. Therefore, we think that it is difficult to distinguish CSH and amyloidosis on radiological images. In conclusion, the imaging findings of our rare case of CSH demonstrated the ill-defined margins of the lesion and its relatively low signal intensity on T2-weighted images. These findings should raise CSH as a differential diagnosis. Acknowledgments We appreciate the assistance of Dr. Morishige Takeshita (Professor, Department of Pathology, Fukuoka University) in the histological diagnosis. Conflict of interest of interest.
The authors declare that they have no conflict
References 1. Dogan S, Barnes L, Cruz-Vetrano WP. Crystal-storing histiocytosis: report of a case, review of the literature (80 cases) and a proposed classification. Head Neck Pathol. 2012;6:111–20. 2. Kusakabe T, Watanabe K, Mori T, Iida T, Suzuki T. Crystalstoring histiocytosis associated with MALT lymphoma of ocular adnexa: a case report with review of literature. Virchows Arch. 2007;450:103–8. 3. Friedman MT, Molho L, Valderrame E, Kahn LB. Crystal-storing histiocytosis associated with a lymphoplasmacytic neoplasm mimicking adult rhabdomyoma; a case report and review of the literature. Arch Pathol Lab Med. 1996;20:1133–6. 4. Jones D, Bhatia VK, Krausz T, Pinkus GS. Crystal-storing histiocytosis: a disorder occurring in plasmacytic tumors expressing immunoglobulin kappa light chain. Hum Pathol. 1999;30:1441–8.
123
Jpn J Radiol 5. Kaminsky IA, Wang AM, Olsen J, Schechter S, Wilson J, Olson R. Central nervous system crystal-storing histiocytosis. AJNR. 2011;32(2):E26–8. 6. Todd WU, Drabick JJ, Benninghoff MG, Frauenhoffer EE, Zander DS. Pulmonary crystal-storing histiocytosis diagnosed by computed tomography-guided fine-needle aspiration. Diagn Cytopathol. 2010;38(4):274–8. 7. Rossi G, Morandi U, Nannini N, Fontana G, Pifferi M, Casali C. Crystal-storing histiocytosis presenting with pleural disease. Histopathology. 2010;56(3):403–5.
123
8. Gean-Marton AD, Kirsch CFE, Vezina LG, Weber AL. Focal amyloidosis of the head and neck: evaluation with CT and MR imaging. Radiology. 1991;181:521–5. 9. Baur A, Stabler A, Lamerz R, Bartl R, Reiser M. Light chain deposition disease in multiple myeloma: MR imaging feature correlated with histopathological findings. Skeletal Radiol. 1998;27:173–6. 10. Li ZS, Li PF, Wang Z, Huang GS. Primary extranodal soft-tissue B-cell lymphoma with abundant immunoglobulin inclusions mimicking adult rhabdomyoma: a case report. J Med Case Rep. 2011;7(5):53.
