could be damaged by this protozoal proteolitic activity. Because the majority of these flagellate protozoa are un-cultivable and molecular studies are costly, with the need for specialized personnel that are within reach of all laboratories, the observation under light microscope based on morphological features continues to be a simple, practical and inexpensive procedure in order to identify these eukaryotic microorganisms in respiratory secretions. R. Martınez-Gir on Protozoal Respiratory Pathology Research Unit, INCLI NICA Foundation, Oviedo, Spain References 1. Ohkuma M, Hongoh Y, Kudo T. Diversity and molecular analyses of yet-uncultivated microorganisms. In: Intestinal Microorganisms of Termites and Other Invertebrates. K€ onig H, Varma A (eds). Berlin, Heidelberg: SpringerVerlag; 2006: pp. 304. 2. Martınez-Giron R, Doganci L, Ribas A. From the 19th century to the 21st, an old dilemma: ciliocytophthoria, multiflagellated protozoa, or both? Diagn Cytopathol 2008;36:609–11. 3. Nisbert B. Nutrition and Feeding Strategies in Protozoa. Manuka, Australia: Croom Helm Ltd.; 1984. 4. Rogerson A, Detwiler A. Abundance of airborne heterotrophic protists in ground level air of South Dakota. Atmos Res 1999;51:35–44. 5. Martınez-Gir on R. Oxymonad and Spirotrichonympha: two anaerobic flagellated protozoa on sputum smears related to asthma. Diagn Cytopathol 2011;39:311–2. 6. van Woerden HC, Ratier-Cruz A, Aleshinloye OB et al. Association between protozoa in sputum and asthma: a case–control study. Respir Med 2011;105:877–84.
Metastatic retinoblastoma of mandible diagnosed on fine needle aspiration cytology DOI:10.1111/cyt.12115
Dear Editor, Retinoblastoma (RB) is one of the commonest tumours of childhood. Lymphatic and haematogenous dissemination usually occurs if there is scleral invasion.1 Metastasis to the mandible is Correspondence: Dr D. Jain, Department of Pathology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India Tel.: +91-11-26594774; Fax: +91-11-2658863; E-mail: [email protected]
© 2013 John Wiley & Sons Ltd Cytopathology 2014, 25, 412–421
rare.2 Herein we report cytology features of RB and emphasize the utility of fine needle aspiration (FNA) in diagnosing this tumour at an uncommon site especially when clinical and radiological diagnoses are misleading and immunocytochemistry can be done. A 3-year-old girl was brought to the cytology clinic for aspiration of a large swelling in the left parotid region, which had been present for 2– 3 weeks, with a clinical diagnosis of parotid neoplasm. Her right eye had been enucleated at 1.9 years of age and histopathological examination revealed features of RB. The tumour showed large areas of necrosis and calcification. There was massive choroidal and scleral invasion with involvement of the retrolaminar portion of the optic nerve head. The resected end of the optic nerve, iris, ciliary body and anterior chamber were tumour free. The child was under regular follow-up with the paediatric oncology unit and received 10 cycles of chemotherapy (vincristine, etoposide and carboplatin) along with radiotherapy. Cerebrospinal fluid (CSF) cytology and bone marrow examination were performed at regular intervals and were negative for tumour. The patient had been tumour free for more than a year when the parents noticed a swelling in the left parotid region. The swelling was large (6 9 6 cm), non-tender and firm in consistency. A computed tomography (CT) scan of the head and neck revealed a soft tissue mass in the left masticator space with sunburst type of aggressive periosteal reaction of the left half of the mandibular body and ramus extending to involve the condyle and coronoid process (Figure 1a). The fat plane with the left parotid was preserved. The radiological appearance suggested an osteosarcoma. FNA of the swelling was performed. Air-dried and alcohol-fixed aspiration smears were stained with May-Gr€ unwald–Giemsa and Papanicolaou stains, respectively. The smears showed a malignant small round cell tumour (MSRCT). The cells were round with scant cytoplasm and hyperchromatic nuclei. Focal necrosis, nuclear molding and mitotic figures were identified (Figure 1b). Attempted pseudorosettes were seen focally. Immunostaining was carried out on a spare unstained alcohol-fixed smear and showed the tumour cells to be strongly immunopositive for synaptophysin (1 : 200; Thermo Scientific, Waltham, MA, USA) confirming metastasis of retinoblastoma (Figure 1c). Later staining of de-stained smears showed focal staining for CD56 (1 : 50; Novocastra, Newcastle upon Tyne, UK); the S-100
Figure 1. (a) Computed tomography shows a sunburst appearance of the tumour in the left half of mandibular body and ramus. (b) A fine needle aspiration smear shows a cellular tumour composed of dispersed round cells with high mitotic activity (Papanicolaou 9600). (c) Synaptophysin immunostain on a cytological smear shows diffuse cytoplasmic positivity of the tumour cells (9600).
(1 : 800; Dako, Glostrup, Denmark) immunostain was negative. No salivary gland tissue was recognized in any of the smears examined. Meanwhile CSF examination revealed the presence of similar tumour cells suggesting central nervous system (CNS) dissemination of the disease. The patient was started on a salvage regimen (vincristine, adriamycin and cyclophosphamide) with palliative intent. Follow-up CSF examination was free of tumour cells after 2 months, when the tumour was reduced in size. However, the child died of disseminated malignancy after 5 months of follow up. Retinoblastoma can spread via multiple routes which include posterior dissemination to the CNS, directly to the orbit through scleral and choroidal invasion and distant metastatic spread.1 The present case had massive choroidal and scleral invasion, which may have been responsible for seeding of tumour cells through the blood vessels into the mandible. Osseous metastases from RB are reported most commonly to the skull and long bones; isolated metastasis to the mandibular bone has been reported in less than 15 cases to date.2–4 The latent period from initial diagnosis to development of malignancy ranged from 0.3 to 8 years in these cases.2 It was 1.5 years in the present case. Metastasis to the mandible usually carries a poor prognosis and more than 90% of patients die as a result of the disease.2 Clinically, the most important differential diagnosis of metastatic retinoblastoma is a second primary malignancy, especially osteosarcoma. The incidence of second cancers increases with the length of time from initial diagnosis.1 Distinguishing a second malignancy from metastatic RB can be challenging
on radiology alone. The final diagnosis can be confirmed by FNAC or biopsy. A CT scan in the present case revealed a sunburst type of periosteal reaction, which is characteristic of osteosarcoma. However, metastatic RB can also show reactive new bone formation and a permeative pattern of bone destruction. Moreover, the patient developed metastasis within 1.5 years of the initial diagnosis and on the contralateral side, which was outside the field of radiation. All these features in the present case along with MSRCT morphology and strong synaptophysin positivity on FNAC confirmed metastatic disease. Morphologically small cell osteogenic sarcoma can mimic any other MSRCT including RB, which was favoured by the absence of osteoid and synaptophysin immunoreactivity. Although the RB1 tumour suppressor gene mutation is widely assumed to be the initiator of all RBs, a clinically and genetically distinct subtype has been identified recently that is characterized by amplification of the MYCN oncogene in the presence of a non-mutated RB1 gene.5 In addition, the role of human papillomavirus infection in a proportion of sporadic RB cases suggests an alternate mechanism of tumour development especially in developing countries.6 FNCA is of proven value in the assessment of head and neck lesions. The present case clinically presented as a parotid gland tumour, which was excluded by univolved parotid on radiology and absence of salivary gland tissue on cytology. FNAC is shown to be of clinical utility in diagnosing a rare metastasis of RB to the mandible when clinical and radiological diagnoses were misleading. © 2013 John Wiley & Sons Ltd Cytopathology 2014, 25, 412–421
R. Walia*, D. Jain*, S. R. Mathur*, S. Bakhshi† and V. K. Iyer* *Department of Pathology, and †Department of Medical Oncology, All India Institute of Medical Sciences, New Delhi, India References 1. Kiss S, Leiderman YI, Mukai S. Diagnosis, classification, and treatment of retinoblastoma. Int Ophthalmol Clin 2008;48:135–47. 2. Taguchi A, Suei Y, Ogawa I et al. Metastatic retinoblastoma of the maxilla and mandible. Dentomaxillofac Radiol 2005;34:126–31.
© 2013 John Wiley & Sons Ltd Cytopathology 2014, 25, 412–421
3. Pandya J, Vlverde K, Heon E et al. Predilection of retinoblastoma metastasis for mandible. Med Pediatr Oncol 2002;38:271–3. 4. Fenton CC, Nish IA, Carmichael RP, S andor GK. Metastatic mandibular retinoblastoma in a child reconstructed with soft tissue matrix expansion grafting: a preliminary report. J Oral Maxillofac Surg 2007;65:2329–35. 5. Rushlow DE, Mol BM, Kennett JY et al. Characterisation of retinoblastomas without RB1 mutations: genomic, gene expression, and clinical studies. Lancet Oncol 2013;14:327–34. 6. Shetty OA, Naresh KN, Banavali SD et al. Evidence for the presence of high risk human papillomavirus in retinoblastoma tissue from nonfamilial retinoblastoma in developing countries. Pediatr Blood Cancer 2012;58:185–90.
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