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4. Pusztaszeri MP, Sauder KJ, Cibas ES, Faquin WC. Fineneedle aspiration of primary Langerhans cell histiocytosis of the thyroid gland, a potential mimic of papillary thyroid carcinoma. Acta Cytol 2013;57:406–12. 5. Pusztaszeri MP, Sadow PM, Faquin WC. Association of CD1a-positive dendritic cells with papillary thyroid carcinoma in thyroid fine-needle aspirations. Cancer Cytopathol 2013;121:206–13. 6. Egeler RM, Neglia JP, Aric M o et al. The relation of Langerhans cell histiocytosis to acute leukemia, lymphomas, and other solid tumors. The LCH-Malignancy Study Group of the Histiocyte Society. Hematol Oncol Clin North Am 1998;12:369–78.
Report of a case emphasizing the clinical utility of fine needle aspiration cytology in the diagnosis of histoid leprosy DOI:10.1111/cyt.12144
Dear Editor, There has been a significant literature on the role of fine needle aspiration cytology (FNAC) in the diagnosis of leprotic lesions, such as pure neuritic, reactionary and rare cases of skeletal leprosy.1,2 Histoid leprosy is a distinct and rare variant of leprosy manifesting with characteristic skin lesions, histopathological features and bacterial morphology.3 Owing to the lack of obvious lymphocytic response, pathologically, it often mimics spindle cell tumours. The literature on the cytodiagnosis of histoid leprosy is rather sparse. Nonetheless, because of its characteristic cytomorphological presentation, it is easily diagnosable by FNAC.4 We report a case highlighting the clinical utility of FNAC in its diagnosis. A 55-year-old man presented with multiple asymptomatic papular and nodular lesions over the trunk and face of 2 years’ duration. Peripheral nerves were thickened. Slit-skin smear examination and biopsy of one of the cutaneous nodules confirmed the diagnosis of lepromatous leprosy with a bacteriological index of 6+. The patient was started on multidrug therapy for multibacillary leprosy. During the course of 5 months of therapy, he developed fresh, firm, 0.8 9 0.8-cm2 to 1.5 9 1.5-cm2 nodular lesions on the right hand (Figure 1a,b), Correspondence: N. Siddaraju, Professor of Pathology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry 605 006, India Tel.: +91-99-44426595; Fax: +91-0413-2272067; E-mail:
[email protected] which were suspected to be caused by erythema nodosum leprosum (ENL). The nodules were subjected to FNAC by the standard procedure. Air-dried and 95% ethanol-fixed smears were stained with routine May–Gr€ unwald–Giemsa (MGG) and Papanicolaou (Pap) stains. Fites stain was performed on one of the air-dried smears. The smears were highly cellular with tight clusters and fragments of spindle cells, in places arranged in a vague palisading manner and having foamy cytoplasm with distinct negative images. Fine vacuolation and negative images were also appreciated in the smear background of MGG smears (Figure 2a–c). No intervening stroma or obvious neutrophilic/lymphocytic infiltrate was seen within the spindle cell fragments, and the Fites stain was strongly positive, corresponding to the negative images (Figure 2d). A cytological diagnosis of ‘histoid leprosy’ was rendered. The term ‘histoid leprosy’ was originally coined in 1963 by Wade.5 Most commonly, it affects multibacillary patients who are on irregular and inadequate dapsone therapy; however, it can also arise de novo.3 This distinct entity received adequate attention only after Sehgal et al.6 documented its immunological profile in 1985. Histoid leprosy is said to be the result of an altered growth pattern of Mycobacterium leprae, caused by the loss of immunity in a localized area. Nodules of histoid leprosy are often confused with lepromatous nodules, and cytomorphology can play a substantial role in distinguishing between the two.4 There are only rare studies and reports describing the cytomorphological features of histoid leprosy.3,4 Two patterns of cytological presentation have been described.4 The most common presentation is a high cell yield3,4 with multilayer palisades of spindle-shaped histiocytes on an endothelial vascular core.4 The spindly macrophages show a dense
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(b)
Figure 1. Clinical photographs showing nodules on the right wrist (a) and hand (b). © 2014 John Wiley & Sons Ltd Cytopathology 2014, 26, 126–133
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(a)
(b)
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Figure 2. Fine needle aspiration cytology smears. (a) A tight, darkly stained cluster of ovoid to spindle cells with vague peripheral nuclear palisading, together with a few negative images and fine vacuolation in the background; (b) a cell cluster with better appreciable cell morphology; (c) prominent negative images of Mycobacterium leprae, together with a cell cluster and rare dissociated vacuolated spindle cells (May–Gr€ unwald–Giemsa, 9400); (d) strong Fites positivity (Fites, 91000).
cytoplasm and elongated blunt vesicular nuclei with fine regular chromatin and small nucleoli. Unlike the mesenchymal fragments, the spindle cell fragments of histoid leprosy lack intervening stroma.3,4 The second pattern comprises isolated or loose groups of polygonal macrophages with ample, multivacuolated, soap bubble-like cytoplasm, centrally or eccentrically placed nucleus, fine chromatin and conspicuous nucleoli. A few multinucleated giant cells exhibiting similar nuclear and cytoplasmic features have also been described. Both patterns are associated with negative images, seen as small crystalloid spaces, better appreciated on Romanowskystained smears. The background may also show fine and coarsely vacuolated material derived from cytoplasmic shedding.4 Characteristically, background lymphocytes are few or negligible.3,4 It is noteworthy that conditions other than histoid leprosy, such as typical and atypical mycobacterial infections, as well as lepromatous leprosy and ENL, also show negative images of mycobacterial organisms.2–4,7
© 2014 John Wiley & Sons Ltd Cytopathology 2014, 26, 126–133
The present case was biopsy-proven lepromatous leprosy with a high bacteriological index. When presented to us, hand lesions raised a suspicion of ENL and also resembled soft tissue tumours. Dermatologists sought FNAC for a definitive opinion, which could be offered because of the distinct cytomorphological presentation. The MGG stain highlighted the foamy nature of the cells with negative images. The spindly nature of tightly cohesive foam cells excluded the possibility of lepromatous leprosy, whilst the absence of a suppurative/neutrophilic response ruled out ENL. The foamy cytoplasm of relatively well-preserved spindle cells and the absence of intervening stroma were not characteristic of any of the spindle cell soft tissue tumours. Clinically, there was no indication of either typical or atypical mycobacterial infection. Thus, both inclusive and exclusive criteria favoured an unequivocal diagnosis of histoid leprosy, avoiding an unnecessary biopsy and directing the appropriate management of the patient. N. G. Rajesh, N. Siddaraju, E. Muthalagan, D. Jain, R. Kumari and P. Balasubramanian Department of Pathology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Pondicherry, India References 1. Siddaraju N, Yaranal PJ. Use of fine needle aspiration cytology in leprotic lesions: a report of 4 cases. Acta Cytol 2007;51:235–8. 2. Malik A, Bhatia A, Singh N, Bhattacharya SN, Arora VK. Fine needle aspiration cytology of reactions in leprosy. Acta Cytol 1999;43:771–6. 3. Patil SY, Malipatil RA. Histoid leprosy: role of fine needle aspiration cytology in the diagnosis. J Sci Soc 2012;39:141–3. 4. Bhake AS, Desikan KV, Jajoo UN. Cytodiagnosis of histoid leprosy. Lepr Rev 2001;72:78–82. 5. Wade HW, Tolentino JG. The histoid variety of lepromatous leprosy. Int J Lepr 1963;31:608–9. 6. Sehgal VN, Srivastava G, Saha K. Immunological status of histoid leprosy. Lepr Rev 1985;56:27–33. 7. Iyengar KR, Basu D. Negative images in the fine needle aspiration cytologic diagnosis of mycobacterial infections. Malays J Pathol 2001;23:89–92.
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