569915
research-article2015
IJSXXX10.1177/1066896915569915International Journal of Surgical PathologyVitkovski et al
Case Report
Malakoplakia of the Thyroid Gland: A Case Report and Review of Literature
International Journal of Surgical Pathology 2015, Vol. 23(4) 308–312 © The Author(s) 2015 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1066896915569915 ijs.sagepub.com
Taisia Vitkovski, DO1, Cristina Costales1, Sheng Chen, MD1, Benjamin Saltman, MD1, and Leonard Kahn, MD1
Abstract Malakoplakia is a rare granulomatous disease that most commonly occurs in the urinary tract. It is characterized by sheets of histiocytes with granular basophilic inclusions and Michaelis-Gutmann bodies. We present an exceedingly rare case of malakoplakia of the thyroid in a 54-year-old Caucasian woman on immunosuppressive therapy for renal transplant performed in 1994. Keywords malakoplakia, thyroid, histiocytes
Introduction Malakoplakia is a rare granulomatous disease that most commonly occurs in the urinary tract. It was first described by Michaelis and Gutmann in 1902, and was named malakoplakia by Von Hansemann.1 Histologically, it is characterized by sheets of histiocytes (Hansemann cells) with granular basophilic inclusions and Michaelis-Gutmann bodies. Malakoplakia has been reported in the gastrointestinal tract, the central nervous system, the gynecologic system, and in the head and neck region. Thyroid involvement is exceedingly rare. To the best of our knowledge, there are only 3 reports in the literature1-3 of thyroid involvement by malakaoplakia. We present a case of malakoplakia of the thyroid in an immunocompromised female patient.
Materials and Methods Report of a Case The patient is a 54-year-old Caucasian woman with a past medical history significant for renal transplant performed in 1994 for polycystic kidney disease. She is currently taking tacrolimus, azathioprine, and prednisone daily for immunosupression. She also has ulcerative colitis, myasthenia gravis, tophaceous gout, and coronary artery disease. She presented initially in January 2014 with hyperthyroidism (thyroid-stimulating hormone 0.1 µIU/mL, free thyroxine 5.15 ng/dL) and severe pain, tenderness, and swelling over the right neck that had developed over 2 weeks. She was admitted to the hospital and was started on methimazole for suspected thyroiditis. Computed tomography (CT) scan of the neck showed a
large right neck mass (5.6 × 4.0 × 4.5 cm) intimately associated with the thyroid, causing deviation of the subglottic trachea and a mass effect on the right internal jugular vein and right common carotid artery (Figure 1A). A thyroid uptake scan showed low uptake in the left lobe consistent with thyroiditis and a nonfunctioning right thyroid. An incision and drainage procedure was performed. Tissue culture confirmed Escherichia coli infection. She was started on ertapenem and was discharged after local wound care had treated the abscess, and she was responding appropriately to the antibiotics. The patient returned to the hospital in May 2014 with recurrence of pain and swelling of the right neck. CT of the neck showed a heterogeneous right neck mass (5.7 × 3.8 × 3.6 cm) associated with the right thyroid lobe, which had decreased in size compared with the previous CT from January. Multiple prominent right paratracheal and esophageal lymph nodes were noted. She was started on imipenem. She underwent laryngoscopy which did not show the presence of a fistula, a potential cause of recurrent bacterial thyroid infection. Antibiotics were changed to ertapenem after culture results, which were again positive for E coli. Ultrasound examination was performed in June and revealed a solid nodule measuring 3.2 × 2.7 × 2.1 cm within the right thyroid lobe, which had overall dimensions of 5.1 × 3.7 × 2.7 cm (Figure 1B). Ultrasound-guided
1
Hofstra North Shore-LIJ Health System, Lake Success, NY, USA
Corresponding Author: Taisia Vitkovski, Department of Pathology, Hofstra North Shore-LIJ Health System, 6 Ohio Drive, Suite 202, Lake Success, NY 11042, USA. Email: [email protected]
Vitkovski et al
309
Figure 1. Computed tomography scan of the soft tissue of the neck in January revealed a right neck mass (5.6 × 4.0 × 4.5 cm) intimately associated with the thyroid gland (A). Ultrasound examination of the right thyroid lobe in June revealed a solid nodule measuring 3.2 × 2.7 × 2.1 cm within the right thyroid lobe, which measured 5.1 × 3.7 × 2.7 cm, overall (B).
fine-needle aspiration (FNA) of the mass was performed and was reported as nondiagnostic (category I). The patient returned to the hospital in July with persistent drainage from the FNA site, neck pain, and difficulty swallowing. She had fever on admission and was treated with imipenem. Thyroid-stimulating hormone (1.12 µIU/ml) and free thyroxine (0.8 ng/dL) were within normal limits. The otolaryngology service was consulted and the decision was made to excise the mass. An extended right thyroidectomy was performed, which included the affected strap muscles and overlying skin. The patient tolerated the procedure well with no recurrence of the mass at 4 weeks postexcision.
Results Intraoperative consultation was performed at the time of surgical resection and demonstrated histiocytes arranged in sheets and single cells with abundant eosinophilic granular cytoplasm and small round nuclei with small nucleoli on touch prep and frozen section. The differential diagnosis included granular cell tumor. The resected right thyroidectomy specimen measured 4.5 × 4.0 × 3.0 cm and contained a white-tan, firm, and homogenous mass measuring 3.5 × 3.5 × 2.5 cm (Figure 2). There was no identifiable thyroid tissue. Permanent sections revealed sheets of histiocytes with granular cytoplasm. Intracellular and extracellular basophilic bodies, many with a targetoid appearance, were seen (Figure 3A). The background was fibrotic with numerous plasma cells and lymphocytes. Residual thyroid follicles were present at the periphery of the lesion.
Figure 2. The right thyroidectomy specimen measured 4.5 × 4.0 × 3.0 cm and had a roughened outer surface. The cut surface showed a firm, white-tan mass measuring 3.5 × 3.5 × 2.5 cm, with focal softened tan-orange area. Normal thyroid tissue was not identified.
Special stains were performed including iron, periodic acid–Schiff (PAS), PAS-diastase, and von Kossa. Iron stain was positive in a patchy distribution, highlighting some Michaelis-Gutmann bodies (Figure 3B). von Kossa stain was strongly positive throughout the lesion (Figure 3C). The histiocytic cytoplasmic granules were PAS positive and diastase resistant (Figure 3D). The findings were diagnostic of malakoplakia. On retrospective review of the
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International Journal of Surgical Pathology 23(4)
Figure 3. The resection specimen showed numerous intra- and extracellular Michaelis-Gutmann bodies ranging in size from 4 to 10 µm, in a background of histiocytes with abundant eosinophilic cytoplasm (A, hematoxylin and eosin, 400×). Iron stain highlighted Michaelis-Gutmann bodies (B, iron, 400×). von Kossa stained the calcium component of Michaelis-Gutmann bodies (C, von Kossa, 400×). Cytoplasmic granules of the histiocytes stained for periodic acid–Schiff (PAS) and were resistant to diastase (D, PAS with diastase, 400×).
review of the frozen section slides, intra- and extracellular lightly basophilic bodies were identified (Figure 5).
Discussion
Figure 4. Fine-needle aspiration (FNA) showed numerous histiocytes with intracytoplasmic debris. The background contained blood, inflammatory cells, and round basophilic bodies consistent with Michaelis-Gutmann bodies. The FNA was interpreted as benign cyst contents. Inset shows a large histiocyte with basophilic cytoplasmic material (figure and inset 400×).
initial FNA, the smears showed numerous histiocytes with engulfed basophilic material in a background of blood, inflammatory cells, and strongly-basophilic material (Figure 4). On
Malakoplakia is a rare granulomatous disease that results from impaired macrophage ability to digest phagocytosed bacteria.4-6 Patients are typically older, with a mean age of 50 years at diagnosis, though a patient as young as 6 weeks of age was diagnosed with malakoplakia of the adrenal gland.7 The urinary tract is the most common site of disease representing 58% to 75% of cases.8,9 The gastrointestinal tract is the second most common site of involvement. Other sites of involvement include the central nervous system, the gynecologic tract, and the head and neck region. Only 3 prior cases of malakoplakia in the thyroid have been reported to our knowledge. There is a female predominance of 4:1 in the urinary tract.9,10 Patients are often immunocompromised. Risk factors include renal transplant, chemotherapy, HIV/AIDS, malignancy, and tuberculosis.10-16 Our patient had a history of a renal transplant, but the other three reported cases of malakoplakia of the thyroid had no reported predisposing factors.
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Figure 5. Touch prep performed at the time of intraoperative consultation showed numerous cells with abundant eosinophilic granular cytoplasm and round to oval nuclei with single prominent nucleoli, interpreted as granular cell tumor. Retrospective review of the slides showed intra- and extracellular (inset) round basophilic bodies ranging in size from 4 to 10 µm, consistent with Michaelis-Gutmann bodies (figure and inset hematoxylin and eosin, 400×).
The cause of the impaired macrophage digestive function is unclear. However, several organisms have been implicated. Coliform bacteria have been found in patients receiving chemotherapy and Rhodococcus equi in patients with acquired immunodeficiency syndrome.12,16,17 Bacilliform organisms were identified in the thyroid reported by Katoh et al2 but not in the cases presented by Larsimont et al3 or Jeffrey et al.1 Malakoplakia appears histologically as sheets of histiocytes with cytoplasmic granular PAS-positive, diastase-resistant inclusions (Hansemann cells). Because of defective lysosomal function, calcium and iron eventually accumulate in the phagosomes, forming the pathognomonic Michaelis-Gutmann bodies. These may be intra- or extracellular, and are basophilic, round, and may be targetoid, with a dense central core.12,18 von Kossa and iron stains demonstrate Michaelis-Gutmann bodies but are unnecessary for the diagnosis. Ultrastructural findings on electron microscopy include the presence of phagolysosomal cytoplasmic inclusions comprising vesicles, electron-dense bodies, membranous lamellae, and crystalline Michaelis-Gutmannbodies 7. Malakoplakia of the thyroid can be difficult to diagnose clinically as patients can present with nonspecific and varied findings. Signs and symptoms can include fever, difficulty swallowing, asymmetrical enlargement of the gland, and destruction of surrounding tissues. These features raise concern for a malignant neoplasm. Two prior reported cases of malakoplakia of the thyroid had euthyroid status1,2 and the case reported by Larsimont et al3 had concomitant autoimmune thyroiditis. Jeffrey et al1 reported the cytologic
findings of malakoplakia of the thyroid, which mimicked a malignant neoplasm because of its large size and destruction of cervical vertebrae. They appropriately concluded that malakoplakia has characteristic cytologic features that should lead pathologists to consider the diagnosis of malakoplakia.1 Malakoplakia is generally regarded as a self-limiting disease, which may undergo spontaneous remission. It is treated with antibiotics such as quinolones, rifampicin, and trimethoprim-sulfamethoxazole, as well as treatment of the underlying condition. However, it may behave in an aggressive fashion. Mortality can be significant with vital organ involvement, especially the kidney.19 While malakoplakia is exceedingly rare in the thyroid, it is important for pathologists to include it in the differential diagnosis of a thyroid mass simulating a malignant neoplasm. Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References 1. Jeffrey PB, Chandrasoma P, Greaves T. Fine needle aspiration cytology of malacoplakia of the thyroid. A case report. Acta Cytol. 1996;40:970-974. 2. Katoh R, Ishizaki T, Tomichi N, Yagawa K, Kurihara H. Malacoplakia of the thyroid gland. Am J Clin Pathol. 1989;92:813-820. 3. Larsimont D, Hamels J, Fortunati D. Thyroid-gland malakoplakia with autoimmune thyroiditis. Histopathology. 1993;23:491-494. 4. Kohl SK, Hans CP. Cutaneous malakiplakia. Arch Pathol Lab Med. 2008;132:113-117. 5. Douglas-Jones AG, Rodd C, James EM, Mills RG. Prediagnostic malakoplakia presenting as a chronic inflammatory mass in the soft tissues of the neck. J Laryngol Otol. 1992;106:173-177. 6. Schmerber S, Lantuejoul S, Lavieille JP, Reyt E. Malakoplakia of the neck. Arch Otolaryngol Head Neck Surg. 2003;129:1240-1242. 7. Sinclair-Smith C, Kahn LB, Cywes S. Malacoplakia in childhood. Case report with ultrastructural observations and review of the literature. Arch Pathol. 1975;99:198-203. 8. Wielenberg AJ, Demos TC, Rangachari B, Turk T. Malacoplakia presenting as a solitary renal mass. AJR Am J Roentgenol. 2004;183:1703-1705. 9. McClure J. Malakoplakia. J Pathol. 1983;140:275-330. 10. Yousef GM, Naghibi B, Hamodat MM. Malakoplakia outside the urinary tract. Arch Pathol Lab Med. 2007;131:297-300. 11. Palazzo JP, Ellison DJ, Garcia IE, et al. Cutaneous malakoplakia simulating relapsing malignant lymphoma. J Cutan Pathol. 1990;17:171-175.
312 12. Govender D, Essa AS. Malakoplakia and tuberculosis. Pathology. 1999;31:280-283. 13. Sterling WA, Hathaway BM, Courington DP, Diethelm AG. Malakoplakia in a renal transplant recipient. A case report. Transplantation. 1975;20:420-424. 14. Arnesen E, Halvarsen S, Skjorten F. Malakoplakia in a renal transplant: report of a case studied by light and electron microscopy. Scand J Urol. Nephrol. 1977;11:93-96. 15. August C, Holzhausen HJ, Schroder S. Renal paren chymal malacoplakia: ultrastructural findings in different stages of morphogenesis. Ultrastruct Pathol. 1994;18:483-491.
International Journal of Surgical Pathology 23(4) 16. Shin MS, Cooper JA Jr, Ho KJ. Pulmonary malacoplakia associated with Rhodococcus equi infection in a patient with AIDS. Chest. 1999;115:889-892. 17. Matter MJ, Gygi C, Gillet M, Gebhard S, Bouzourene H. Malacoplakia simulating organ invasion in a rectosigmoid adenocarcinoma: report of a case. Dis Colon Rectum. 2001;44:1371-1375. 18. Rickert CH, August C, Brandt M, Wagner V, Paulus W. Cerebral malakoplakia associated with Escherichia coli infection. Acta Neuropathol. 2000;99:595-598. 19. Stanton MJ, Maxted W. Malakoplakia: a study of the literature and current concepts of pathogenesis, diagnosis and treatment. J Urol. 1981;125:139-146.
Copyright of International Journal of Surgical Pathology is the property of Sage Publications Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
research-article2015
IJSXXX10.1177/1066896915569915International Journal of Surgical PathologyVitkovski et al
Case Report
Malakoplakia of the Thyroid Gland: A Case Report and Review of Literature
International Journal of Surgical Pathology 2015, Vol. 23(4) 308–312 © The Author(s) 2015 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1066896915569915 ijs.sagepub.com
Taisia Vitkovski, DO1, Cristina Costales1, Sheng Chen, MD1, Benjamin Saltman, MD1, and Leonard Kahn, MD1
Abstract Malakoplakia is a rare granulomatous disease that most commonly occurs in the urinary tract. It is characterized by sheets of histiocytes with granular basophilic inclusions and Michaelis-Gutmann bodies. We present an exceedingly rare case of malakoplakia of the thyroid in a 54-year-old Caucasian woman on immunosuppressive therapy for renal transplant performed in 1994. Keywords malakoplakia, thyroid, histiocytes
Introduction Malakoplakia is a rare granulomatous disease that most commonly occurs in the urinary tract. It was first described by Michaelis and Gutmann in 1902, and was named malakoplakia by Von Hansemann.1 Histologically, it is characterized by sheets of histiocytes (Hansemann cells) with granular basophilic inclusions and Michaelis-Gutmann bodies. Malakoplakia has been reported in the gastrointestinal tract, the central nervous system, the gynecologic system, and in the head and neck region. Thyroid involvement is exceedingly rare. To the best of our knowledge, there are only 3 reports in the literature1-3 of thyroid involvement by malakaoplakia. We present a case of malakoplakia of the thyroid in an immunocompromised female patient.
Materials and Methods Report of a Case The patient is a 54-year-old Caucasian woman with a past medical history significant for renal transplant performed in 1994 for polycystic kidney disease. She is currently taking tacrolimus, azathioprine, and prednisone daily for immunosupression. She also has ulcerative colitis, myasthenia gravis, tophaceous gout, and coronary artery disease. She presented initially in January 2014 with hyperthyroidism (thyroid-stimulating hormone 0.1 µIU/mL, free thyroxine 5.15 ng/dL) and severe pain, tenderness, and swelling over the right neck that had developed over 2 weeks. She was admitted to the hospital and was started on methimazole for suspected thyroiditis. Computed tomography (CT) scan of the neck showed a
large right neck mass (5.6 × 4.0 × 4.5 cm) intimately associated with the thyroid, causing deviation of the subglottic trachea and a mass effect on the right internal jugular vein and right common carotid artery (Figure 1A). A thyroid uptake scan showed low uptake in the left lobe consistent with thyroiditis and a nonfunctioning right thyroid. An incision and drainage procedure was performed. Tissue culture confirmed Escherichia coli infection. She was started on ertapenem and was discharged after local wound care had treated the abscess, and she was responding appropriately to the antibiotics. The patient returned to the hospital in May 2014 with recurrence of pain and swelling of the right neck. CT of the neck showed a heterogeneous right neck mass (5.7 × 3.8 × 3.6 cm) associated with the right thyroid lobe, which had decreased in size compared with the previous CT from January. Multiple prominent right paratracheal and esophageal lymph nodes were noted. She was started on imipenem. She underwent laryngoscopy which did not show the presence of a fistula, a potential cause of recurrent bacterial thyroid infection. Antibiotics were changed to ertapenem after culture results, which were again positive for E coli. Ultrasound examination was performed in June and revealed a solid nodule measuring 3.2 × 2.7 × 2.1 cm within the right thyroid lobe, which had overall dimensions of 5.1 × 3.7 × 2.7 cm (Figure 1B). Ultrasound-guided
1
Hofstra North Shore-LIJ Health System, Lake Success, NY, USA
Corresponding Author: Taisia Vitkovski, Department of Pathology, Hofstra North Shore-LIJ Health System, 6 Ohio Drive, Suite 202, Lake Success, NY 11042, USA. Email: [email protected]
Vitkovski et al
309
Figure 1. Computed tomography scan of the soft tissue of the neck in January revealed a right neck mass (5.6 × 4.0 × 4.5 cm) intimately associated with the thyroid gland (A). Ultrasound examination of the right thyroid lobe in June revealed a solid nodule measuring 3.2 × 2.7 × 2.1 cm within the right thyroid lobe, which measured 5.1 × 3.7 × 2.7 cm, overall (B).
fine-needle aspiration (FNA) of the mass was performed and was reported as nondiagnostic (category I). The patient returned to the hospital in July with persistent drainage from the FNA site, neck pain, and difficulty swallowing. She had fever on admission and was treated with imipenem. Thyroid-stimulating hormone (1.12 µIU/ml) and free thyroxine (0.8 ng/dL) were within normal limits. The otolaryngology service was consulted and the decision was made to excise the mass. An extended right thyroidectomy was performed, which included the affected strap muscles and overlying skin. The patient tolerated the procedure well with no recurrence of the mass at 4 weeks postexcision.
Results Intraoperative consultation was performed at the time of surgical resection and demonstrated histiocytes arranged in sheets and single cells with abundant eosinophilic granular cytoplasm and small round nuclei with small nucleoli on touch prep and frozen section. The differential diagnosis included granular cell tumor. The resected right thyroidectomy specimen measured 4.5 × 4.0 × 3.0 cm and contained a white-tan, firm, and homogenous mass measuring 3.5 × 3.5 × 2.5 cm (Figure 2). There was no identifiable thyroid tissue. Permanent sections revealed sheets of histiocytes with granular cytoplasm. Intracellular and extracellular basophilic bodies, many with a targetoid appearance, were seen (Figure 3A). The background was fibrotic with numerous plasma cells and lymphocytes. Residual thyroid follicles were present at the periphery of the lesion.
Figure 2. The right thyroidectomy specimen measured 4.5 × 4.0 × 3.0 cm and had a roughened outer surface. The cut surface showed a firm, white-tan mass measuring 3.5 × 3.5 × 2.5 cm, with focal softened tan-orange area. Normal thyroid tissue was not identified.
Special stains were performed including iron, periodic acid–Schiff (PAS), PAS-diastase, and von Kossa. Iron stain was positive in a patchy distribution, highlighting some Michaelis-Gutmann bodies (Figure 3B). von Kossa stain was strongly positive throughout the lesion (Figure 3C). The histiocytic cytoplasmic granules were PAS positive and diastase resistant (Figure 3D). The findings were diagnostic of malakoplakia. On retrospective review of the
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International Journal of Surgical Pathology 23(4)
Figure 3. The resection specimen showed numerous intra- and extracellular Michaelis-Gutmann bodies ranging in size from 4 to 10 µm, in a background of histiocytes with abundant eosinophilic cytoplasm (A, hematoxylin and eosin, 400×). Iron stain highlighted Michaelis-Gutmann bodies (B, iron, 400×). von Kossa stained the calcium component of Michaelis-Gutmann bodies (C, von Kossa, 400×). Cytoplasmic granules of the histiocytes stained for periodic acid–Schiff (PAS) and were resistant to diastase (D, PAS with diastase, 400×).
review of the frozen section slides, intra- and extracellular lightly basophilic bodies were identified (Figure 5).
Discussion
Figure 4. Fine-needle aspiration (FNA) showed numerous histiocytes with intracytoplasmic debris. The background contained blood, inflammatory cells, and round basophilic bodies consistent with Michaelis-Gutmann bodies. The FNA was interpreted as benign cyst contents. Inset shows a large histiocyte with basophilic cytoplasmic material (figure and inset 400×).
initial FNA, the smears showed numerous histiocytes with engulfed basophilic material in a background of blood, inflammatory cells, and strongly-basophilic material (Figure 4). On
Malakoplakia is a rare granulomatous disease that results from impaired macrophage ability to digest phagocytosed bacteria.4-6 Patients are typically older, with a mean age of 50 years at diagnosis, though a patient as young as 6 weeks of age was diagnosed with malakoplakia of the adrenal gland.7 The urinary tract is the most common site of disease representing 58% to 75% of cases.8,9 The gastrointestinal tract is the second most common site of involvement. Other sites of involvement include the central nervous system, the gynecologic tract, and the head and neck region. Only 3 prior cases of malakoplakia in the thyroid have been reported to our knowledge. There is a female predominance of 4:1 in the urinary tract.9,10 Patients are often immunocompromised. Risk factors include renal transplant, chemotherapy, HIV/AIDS, malignancy, and tuberculosis.10-16 Our patient had a history of a renal transplant, but the other three reported cases of malakoplakia of the thyroid had no reported predisposing factors.
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Vitkovski et al
Figure 5. Touch prep performed at the time of intraoperative consultation showed numerous cells with abundant eosinophilic granular cytoplasm and round to oval nuclei with single prominent nucleoli, interpreted as granular cell tumor. Retrospective review of the slides showed intra- and extracellular (inset) round basophilic bodies ranging in size from 4 to 10 µm, consistent with Michaelis-Gutmann bodies (figure and inset hematoxylin and eosin, 400×).
The cause of the impaired macrophage digestive function is unclear. However, several organisms have been implicated. Coliform bacteria have been found in patients receiving chemotherapy and Rhodococcus equi in patients with acquired immunodeficiency syndrome.12,16,17 Bacilliform organisms were identified in the thyroid reported by Katoh et al2 but not in the cases presented by Larsimont et al3 or Jeffrey et al.1 Malakoplakia appears histologically as sheets of histiocytes with cytoplasmic granular PAS-positive, diastase-resistant inclusions (Hansemann cells). Because of defective lysosomal function, calcium and iron eventually accumulate in the phagosomes, forming the pathognomonic Michaelis-Gutmann bodies. These may be intra- or extracellular, and are basophilic, round, and may be targetoid, with a dense central core.12,18 von Kossa and iron stains demonstrate Michaelis-Gutmann bodies but are unnecessary for the diagnosis. Ultrastructural findings on electron microscopy include the presence of phagolysosomal cytoplasmic inclusions comprising vesicles, electron-dense bodies, membranous lamellae, and crystalline Michaelis-Gutmannbodies 7. Malakoplakia of the thyroid can be difficult to diagnose clinically as patients can present with nonspecific and varied findings. Signs and symptoms can include fever, difficulty swallowing, asymmetrical enlargement of the gland, and destruction of surrounding tissues. These features raise concern for a malignant neoplasm. Two prior reported cases of malakoplakia of the thyroid had euthyroid status1,2 and the case reported by Larsimont et al3 had concomitant autoimmune thyroiditis. Jeffrey et al1 reported the cytologic
findings of malakoplakia of the thyroid, which mimicked a malignant neoplasm because of its large size and destruction of cervical vertebrae. They appropriately concluded that malakoplakia has characteristic cytologic features that should lead pathologists to consider the diagnosis of malakoplakia.1 Malakoplakia is generally regarded as a self-limiting disease, which may undergo spontaneous remission. It is treated with antibiotics such as quinolones, rifampicin, and trimethoprim-sulfamethoxazole, as well as treatment of the underlying condition. However, it may behave in an aggressive fashion. Mortality can be significant with vital organ involvement, especially the kidney.19 While malakoplakia is exceedingly rare in the thyroid, it is important for pathologists to include it in the differential diagnosis of a thyroid mass simulating a malignant neoplasm. Declaration of Conflicting Interests The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding The author(s) received no financial support for the research, authorship, and/or publication of this article.
References 1. Jeffrey PB, Chandrasoma P, Greaves T. Fine needle aspiration cytology of malacoplakia of the thyroid. A case report. Acta Cytol. 1996;40:970-974. 2. Katoh R, Ishizaki T, Tomichi N, Yagawa K, Kurihara H. Malacoplakia of the thyroid gland. Am J Clin Pathol. 1989;92:813-820. 3. Larsimont D, Hamels J, Fortunati D. Thyroid-gland malakoplakia with autoimmune thyroiditis. Histopathology. 1993;23:491-494. 4. Kohl SK, Hans CP. Cutaneous malakiplakia. Arch Pathol Lab Med. 2008;132:113-117. 5. Douglas-Jones AG, Rodd C, James EM, Mills RG. Prediagnostic malakoplakia presenting as a chronic inflammatory mass in the soft tissues of the neck. J Laryngol Otol. 1992;106:173-177. 6. Schmerber S, Lantuejoul S, Lavieille JP, Reyt E. Malakoplakia of the neck. Arch Otolaryngol Head Neck Surg. 2003;129:1240-1242. 7. Sinclair-Smith C, Kahn LB, Cywes S. Malacoplakia in childhood. Case report with ultrastructural observations and review of the literature. Arch Pathol. 1975;99:198-203. 8. Wielenberg AJ, Demos TC, Rangachari B, Turk T. Malacoplakia presenting as a solitary renal mass. AJR Am J Roentgenol. 2004;183:1703-1705. 9. McClure J. Malakoplakia. J Pathol. 1983;140:275-330. 10. Yousef GM, Naghibi B, Hamodat MM. Malakoplakia outside the urinary tract. Arch Pathol Lab Med. 2007;131:297-300. 11. Palazzo JP, Ellison DJ, Garcia IE, et al. Cutaneous malakoplakia simulating relapsing malignant lymphoma. J Cutan Pathol. 1990;17:171-175.
312 12. Govender D, Essa AS. Malakoplakia and tuberculosis. Pathology. 1999;31:280-283. 13. Sterling WA, Hathaway BM, Courington DP, Diethelm AG. Malakoplakia in a renal transplant recipient. A case report. Transplantation. 1975;20:420-424. 14. Arnesen E, Halvarsen S, Skjorten F. Malakoplakia in a renal transplant: report of a case studied by light and electron microscopy. Scand J Urol. Nephrol. 1977;11:93-96. 15. August C, Holzhausen HJ, Schroder S. Renal paren chymal malacoplakia: ultrastructural findings in different stages of morphogenesis. Ultrastruct Pathol. 1994;18:483-491.
International Journal of Surgical Pathology 23(4) 16. Shin MS, Cooper JA Jr, Ho KJ. Pulmonary malacoplakia associated with Rhodococcus equi infection in a patient with AIDS. Chest. 1999;115:889-892. 17. Matter MJ, Gygi C, Gillet M, Gebhard S, Bouzourene H. Malacoplakia simulating organ invasion in a rectosigmoid adenocarcinoma: report of a case. Dis Colon Rectum. 2001;44:1371-1375. 18. Rickert CH, August C, Brandt M, Wagner V, Paulus W. Cerebral malakoplakia associated with Escherichia coli infection. Acta Neuropathol. 2000;99:595-598. 19. Stanton MJ, Maxted W. Malakoplakia: a study of the literature and current concepts of pathogenesis, diagnosis and treatment. J Urol. 1981;125:139-146.
Copyright of International Journal of Surgical Pathology is the property of Sage Publications Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
