كيس ليمفاوي سرطاين يف القصبة اهلوائية واحلنجرة الورم الذي أوشك علي خطف أنفاسها Tracheolaryngeal Adenoid Cystic Carcinoma The tumour that almost took her breath away Dear Sir, A 40-year-old female patient presented to the Southern Command Hospital, Pune, India, in August 2015 with a six-month history of breathlessness. She was experiencing three to four episodes of dyspnoea per week with each episode lasting a few minutes. The breathlessness was aggravated on exertion and relieved with rest. She had no known comorbidities and had previously been treated symptomatically for asthma with no significant improvement. An indirect laryngoscopy revealed a proliferative growth inferior to the postcricoid area which was partially filling the trachea without affecting the glottic closure [Figure 1A]. Contrast-enhanced computed tomography of the neck revealed a well-defined soft tissue lesion (2.5 x 2.2 x 2.2 cm) in the infraglottic cavity and upper trachea with no significant enhancement [Figure 1B]. An emergency tracheostomy was performed and a biopsy revealed tumour cells arranged in cribriform structures, tubules and clusters amidst a fibrous stroma [Figure 1C]; the cells had minimal eosinophilic cytoplasm, indistinct cell borders, oval hyperchromatic nuclei and inconspicuous nucleoli. On subsequent elective excision, all of the surgical margins were positive with the tumour abutting the tracheal cartilage [Figure 1D] and involving the inferior and posterior margins of the left lobe of the thyroid. The tumour showed similar histomorphology with foci of perineural invasion. A diagnosis of an adenoid cystic carcinoma (ADCC) was made at stage T4N0M0, indicating no regional lymph node or distant metastasis. As all of the surgical margins and the thyroid gland were seen to be involved during a frozen section procedure, the surgeons opted for palliative surgery with minimal local resection of the cricoid cartilage and first tracheal ring in addition to a total thyroidectomy. The defect was closed by end-to-end anastomosis with no attempt made at reconstruction. The patient subsequently received palliative radiotherapy (70 Gy) for four weeks. Due to the possibility of mucosal erosion and tracheal restenosis, the tracheostomy was continued for 12 weeks and the incision was closed at the end of the 14th week. The patient was stable with no clinical evidence of recurrence at a four-month follow-up. ADCCs are malignant neoplasms of the laryngeal salivary glands characterised by a protracted and aggressive clinical course.1 These carcinomas form less than 1% of all tracheolaryngeal malignancies and are known to reach large sizes; they usually occur among patients in their fifth and sixth decades of life and no gender predilection has been observed.2 As with the current case, ADCC can present with symptoms of obstruction, such as breathlessness.3 The differential diagnosis for ADCC includes polymorphous low-grade adeno- carcinomas, basal cell adenomas, mixed tumours and basaloid squamous cell carcinomas.4 A cribriform pattern of tumour cells is typical of ADCC; however, this pattern is rarely seen in basal cell adenomas, basaloid squamous cell carci- nomas and mixed tumours. While distinc- tion between polymorphous low-grade adenocarcinomas and ADCCs can be challenging, the Ki-67 index is 10 times higher for the latter.4 In addition, smooth letter to the editor Sultan Qaboos University Med J, May 2016, Vol. 16, Iss. 2, pp. 261–262, Epub. 15 May 16 Submitted 13 Jan 16 Revision Req. 3 Feb 16; Revision Recd. 8 Feb 16 Accepted 25 Feb 16 doi: 10.18295/squmj.2016.16.02.024 Figure 1A‒D: A: Fibre-optic bronchoscopy image of a 40-year-old female with a tracheolaryngeal adenoid cystic carcinoma showing a proliferative growth (arrow) inferior to the postcricoid area, partially filling the trachea without hampering the glottic closure. B: Contrast- enhanced computed tomography of the neck revealing a well-defined soft tissue lesion (arrow) in the infraglottic area and upper trachea with no significant enhancement. C: Haematoxylin and eosin stain at x400 magnification showing tumour cells arranged in cribriform structures, tubules and clusters amidst a fibrous stroma. D: Haematoxylin and eosin stain at x400 magnification showing the tumour abutting the tracheal cartilage. Tracheolaryngeal Adenoid Cystic Carcinoma The tumour that almost took her breath away e262 | SQU Medical Journal, May 2016, Volume 16, Issue 2 muscle markers of myoepithelial differentiation are positive in cases of ADCC but negative for polymorphous low-grade adenocarcinomas. Pseudocysts are usually positive with periodic acid-Schiff and Alcian blue stains and contain basement membrane components.4 The epithelial cells are usually positive for carcinoembryonic and epithelial membrane antigens while duct-lining cells are positive for cluster of differentiation 117 and tumour protein 63. Alterations in chromosomes 6q, 9p and 17p12‒13 are the most frequent cytogenetic alterations reported.4 Although the histologic appearance of ADCC is well-described with certain features that may predict prognosis, surgical removal is often difficult given the infiltrative nature of these neoplasms with their propensity to invade into the adjacent tissues and extend along nerve segments.5 This is further compounded by the deceptively circumscribed macroscopic appearance of the tumours.3 These factors are challenging for surgeons attempting to remove the tumour with negative margins. Due to inadequate surgical excision, recurrence rates are high, ranging from 75‒90%.6 Radical surgery has not been shown to improve survival rates or decrease local recurrence when compared with a conservative surgical approach and postoperative radiation.3 Optimal treatment therefore remains wide local excision with or without postoperative radiation. Rajat Bajaj,1 *Manoj M. Gopal,1 Sunil Mathews2 Departments of 1Pathology and 2Otorhinolaryngology, Armed Forces Medical College, Pune, India *Corresponding Author e-mail: manoj.gopal@gmail.com References 1. Cason RA, Binnie WH, Speight PM, Barrett AW, Wright JM. Lucas’s Pathology of Tumors of the Oral Tissues. 5th ed. London, UK: Churchill Livingstone, 1998. Pp. 330–5. 2. Jaso J, Malhotra R. Adenoid cystic carcinoma. Arch Pathol Lab Med 2011; 135:511–15. doi: 10.1043/2009-0527-RS.1. 3. Wang H, Xu L, Li F. Subglottic adenoid cystic carcinoma mistaken for asthma. J Zhejiang Univ Sci B 2009; 10:707–10. doi: 10.1631/jzus. B0920071. 4. Chundru NSV, Amudala R, Thankappan P, Nagaraju CD. Adenoid cystic carcinoma of palate: A case report and review of literature. Dent Res J India: 2013 Feb;10(2):274–8. 5. Matsuba HM, Spector GJ, Thawley SE, Simpson JR, Mauney M, Pikul FJ. Adenoid cystic salivary gland carcinoma: A histomorphologic review of treatment failure patterns. 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