Volume 4, Issue 1 , Pages 42-44, January 2009
Inflammatory myofibroblastic tumor larynx mimicking laryngeal papillomatosis
Article Outline
Summary
Inflammatory myofibroblastic tumor (IMT) of larynx is an unusual benign proliferate lesion rarely seen in pediatric age group. A 10-year-old male child presented with history of hoarseness of voice for 6-month duration and indirect laryngoscopy showed an ulcerative, warty growth involving the right vocal cord. The patient underwent microlaryngeal surgery under general anaesthesia and growth was excised completely. The histopathology showed spindle cells arranged in fasciculate pattern with myxoid background and focal hyalinization. The immunostaining showed positivity of spindle cells to vimentin and muscle specific actin confirming the diagnosis of IMT. The voice of child improved after 2 months and had regular follow up for 2 years with no recurrence.
Keywords: Inflammatory myofibroblastic tumor, Larynx, Laryngeal pseudotumor
1. Introduction
Inflammatory myofibroblastic tumor represents a heterogenous group of unusual pseudo-neoplastic lesions that appears to encompass a spectrum of histopathologic features ranging from plasma cell-rich lesions to those dominated by myofibroblasts. Although IMT was initially described in the lung [1], [2], it has subsequently been reported in various extrapulmonary sites including head and neck. In the head and neck the most commonly involved areas are paranasal sinus [3], orbit [4] and rarely described in larynx [5]. Till date, only 21 confirmed cases of laryngeal IMT have been described in the English literature [6]. The patients are mostly age group above the second decades of life, though one case report of age 2-year-old child has been also described in the literature [7].
The neoplastic lesion of larynx in pediatric age group are approximately 98% benign in nature [8]. The squamous papilloma being the commonest among the benign lesion others are those arising from connective tissues, e.g., vascular malformation and neurogenic tumors. In our case report clinically it was looking as squamous papilloma but the histopathology revealed the diagnosis of IMT.
2. Case report
A 10-year-old male child presented to our department with history hoarseness of voice for 6 months duration. There was no associated history of fever, weight loss, trauma or difficulty in swallowing. His laboratory investigation revealed haemoglobin of 11
g%, 14mm ESR in first hour, and a normal differential leukocyte count. The flexible endoscopy showed a exophytic mass involving the right cord whole length and was reaching till anterior commissure. The cord was mobile and no cervical lymphadenopathy on palpitation. There was no recent history of fever, weight loss. A clinical diagnosis of respiratory pappillomatosis was made and patient was taken up for endoscopic biopsy and micro laryngeal surgery. Intraoperatively whole of exophytic mass was removed and hemostasis was achieved and specimen sent for histopathology which revealed the diagnosis of IMF. On gross examination there was extensive ulceration of the polypoidal tissue. On microscopy there were spindle-shaped cells arranged in a fassiculated pattern with a sigmoid background and focal area of hylinazation (Fig. 1). The cells were having elongated nuclei with moderate amount of eosinophilic cytoplasm. On immunohistochemical analysis spindle cells showed positivity to vimentin, muscle specific actin and smooth muscle actin (Fig. 2), staining for desmin, cytokeratin, 5–100 proteins and CD34 were negative confirming the diagnosis of IMT. The patient was kept on monthly follow up and voice returned to normal after 2 months. He is in regular follow up and free from recurrence in 2 years follow up.
Fig. 1.
Microphotographs showing cellular tumor with spindle to oval shape cells in a heavy inflammatory background.
Fig. 2.
Microphotograph showing spindle to oval shape cells with SMA positivity.
3. Discussion
IMT was the term coined by Weing et al. [5] indicating a proliferative growth in which the predominant cells is a myofibroblast. IMT have been reported through out the body under a variety of names and majority of lesions follows a benign clinical course and rarely reoccur locally [8].
The etiology of IMT is unknown. The potential subclinical traumatic stimuli like voice abuse, excessive coughing, acid-reflux are often associated with wound healing which includes the presence of myofibroblast. In certain instances, this reaction can be so proliferative resulting in the presence of a clinically apparent mass lesions dominated by the presence of myofibroblasts.
Differential diagnosis of glottic growth in a pediatric age group of 8–10 years are recurrent respiratory papillomatosis, vocal polyp and granulomatous pathology. Recurrent respiratory papillomatosis is caused by viral infection by HIV-16, -18 and is the commonest lesions affecting the larynx in pediatric age group. In this patient this clinical diagnosis was made preoperatively.
Till date 21 laryngeal IMT have been described in the English literature [9]. The mean age of these patients was 44.5 years (range 2–74 years) and the male:female ratio was 1.6:1. Hoarsness and dysphagia are the most frequent symptoms of IMT, the treatment options described in the literature are endoscopic excision (with or without laser), high dose steroids and rarely radiation and open excisions. Endoscopic excision with or without steriods is considered to be first line of treatment as only few recurrence have been reported in literature [10]. The recurrence rate of laryngeal IMT is about 18%. Radiation therapy is used in the cases of local recurrence, open excision is usually advocated in cases of recurrence, poor endoscopic visualization or when malignancy cannot be excluded, respectively [11].
Histopathology features that helps in the diagnosis of IMT includes the absence of necrosis, absence of atypical figures of mitosis, a mitotic rate of less than two percent 10 HPF, mild cellular pleomorphism, absence of infiltrating growth and presence of polyclonality of plasma and mixed inflammatory infiltrate [12]. Ultra-structured studies shows spindle cells with elongated cytoplasmic processes. The immunocytochemistry positivity for vimentin and smooth muscle actin with morphological features and negativity for cytokeratin, CD34 helps to made the diagnosis of IMT.
References
- . Plasma cell granuloma of the lung. Cancer. 1973;31:191–208
- . The pulmonary plasma cell/histocytoma complex. Histophatology. 1984;8:903–916
- . Inflammatory pseudotumor of the paranasal sinuses. Acta Otorhinolaryngol Esp. 1990;41:351–353
- . Pseudotumor of the orbit, clinical, pathologic and radiologic evaluation. Radiol Clin North Am. 1999;37:151–168
- . Inflammatory myofibroblastic tumor of the larynx. A clinicopathologic study of eight cases simulating a malignant spindle cell neoplasm. Cancer. 1995;76:2217–2229
- . Inflammatory myofibroblastic tumor in the larynx: clinico pathologic features and histogenesis. Acta Oto-laryngologica. 2005;125:215–219
- . Inflammatory myofibroblastic tumor in larynx in 2 old male child. J Otorhinolaryngol Relat Spec. 2005;67(2):101–105
- . Inflammatory fibrosarcoma of the mesentery and retroperitoneum—a tumor closely stimulating inflammatory pseudo-tumor. Am J Surg Pathol. 1991;15:1146–1156
- . Management of inflammatory pseudo tumor of the larynx. Otolaryngol Head and Neck Surg. 2007;136:139–141
- . Recurrent inflammatory myofibroblastic tumor of the glottis mimicking malignancy. Am J Otolaryngol. 1997;18:121–126
- . Extrapulmonary inflammatory myofibroblastic tumor (inflammatory pseudotumor). A clinico-pathologic and immunohistochemical study of 84 cases. Am J Surg Pathol. 1995;19:859–872
- . Inflammatory myofibroblastic tumor (Plasma cells granuloma). Clnico-pathologic study of 20 cases with immuno-histochemical and ultra structural observations. Am J Clin Pathol. 1990;94:538–546
PII: S1871-4048(08)00043-9
doi:10.1016/j.pedex.2008.05.006
© 2008 Elsevier Ireland Ltd. All rights reserved.
Volume 4, Issue 1 , Pages 42-44, January 2009
