IgG4-Related Disease of the Thyroid Gland Requiring Emergent Total Thyroidectomy: A Case Report Abstract IgG4-related disease of the thyroid gland is a recently recognized subtype of thyroiditis, often with rapid progression requiring surgical treatment. It is considered as a spectrum of disease varying from early IgG4-related Hashimoto’s thyroiditis (HT) pattern to late fibrosing HT or Riedel’s thyroiditis patterns. Here, we report a 47-year-old Malay woman presenting with progressively painless neck swelling over 3 years and subclinical hypothyroidism. Computed tomography (CT) scan revealed diffuse thyroid enlargement (up to 13 cm) with retrosternal extension and without regional lymphadenopathy. Fine needle aspiration of the thyroid showed a limited number of follicular epithelial cell groups with widespread Hurthle cell change and scanty background colloid, but no evidence of lymphocytosis. The cytologic features fell into the category of ‘atypia of undetermined significance’. Subsequently, the patient developed hypercapnic respiratory failure secondary to extrinsic upper airway compression by the thyroid mass and underwent emergent total thyroidectomy. Histology of the thyroid showed diffuse dense lymphoplasmacytic infiltrate and fibrosis. Follicular cells exhibited reactive nuclear features and some Hurthle cell change. IgG4+ plasma cells were over 40/high power field while overall IgG4/IgG ratio was above 50%. The overall features suggest the diagnosis of IgG4-related disease of the thyroid gland in the form of IgG4-related HT. Post-surgery, the patient was found to have markedly elevated serum IgG4 concentration but PET/CT did not show significant increased fludeoxyglucose uptake in other areas. Her recovery was complicated by a ventilator-associated pneumonia with empyema, limiting early use of corticosteroids for treatment of IgG4-related disease.

What Is the Non-calcifying Langerhans Cell-Rich Variant of Calcifying Epithelial Odontogenic Tumor?

Who Originally Described Pindborg Tumor?

Adult-Type Rhabdomyoma of the Larynx in Birt–Hogg–Dubé Syndrome: Evidence for a Real Association Abstract The autosomal dominant Birt–Hogg–Dubé syndrome is known to be associated with skin, lung and kidney lesions. It is caused by heterozygous germline mutations in the folliculin gene and has a high penetrance. We report the case of a 51 year old woman with Birt–Hogg–Dubé syndrome who presented with a laryngeal mass. Imaging confirmed a mass centered on the piriform sinus and following excision histological examination confirmed the lesion was composed of polygonal cells with abundant eosinophilic cytoplasm consistent with a rhabdomyoma. Laryngeal rhabdomyoma is rare condition and has not been previously described in association with Birt–Hogg–Dubé. In patients with Birt–Hogg–Dubé syndrome who develop upper aerodigestive tract symptoms secondary to mass lesion an adult-type rhabdomyoma might be considered as a differential, with endoscopic excision being the treatment of choice.

Actinomycosis Presenting as Macroglossia: Case Report and Review of Literature Abstract Cervicofacial actinomycosis is a common form of Actinomyces infection. However, the latter seldom occurs in the tongue. We present a case of a 66 year-old man with macroglossia caused by actinomycosis of the tongue. Radiographic features were compatible with a chronic inflammatory disease. Biopsies revealed granulomas containing giant cells and Gram positive bacterial clusters consistent with actinomycosis. The patient was treated with a 22 week course of antibiotics. Imaging showed a notable improvement in the extent of the lesions 1 year later. The patient was asymptomatic and in good condition during his second year follow-up. Diagnosis of actinomycosis of the tongue can prove to be challenging because of the non-specific nature of its symptoms, clinical signs, and radiographic features. Isolation of Actinomyces sp. is an added diagnostic hurdle, because of its fastidious nature.

Papillary Carcinoma of Stensen’s Duct with Intestinal Differentiation Abstract Stensen’s duct carcinoma (StDC) is an extremely rare neoplasm, with fewer than 40 cases reported in the literature. We report a unique case of primary StDC with papillary features and intestinal differentiation of a 74-year-old male. We discuss the radiologic and pathologic correlation along with the differential diagnosis of this rare entity.

Primary Laryngeal Tuberculosis: A Series of 15 Cases Abstract Tuberculosis usually involves the lungs, but can also involve various other organs. Extra pulmonary tuberculosis is very rarely confined to the larynx in the absence of an associated pulmonary lesion. In this retrospective study, clinicopathological characteristics of patients with final diagnosis of laryngeal tuberculosis (LTB) were reviewed. The diagnosis of LTB was based on: (1) the existence of chronic granulomatous inflammation with caseous necrosis in the histopathology of laryngeal lesions or (2) the presence of laryngeal lesions with atypical histopathology (chronic granulomatous inflammation) which had a complete response to anti-tuberculosis therapy. Fifteen cases with a diagnosis of LTB were collected. The patients’ age ranged between 24 and 75 years with a mean of 49 years. On laryngoscopy, 66.6% of cases (10/15) had an ulceroproliferative lesion while the remaining 33.3% of cases (5/15) had an exophytic growth. The pathology of laryngeal lesions revealed chronic granulomatous inflammation with caseous necrosis in nine cases and chronic granulomatous inflammation without necrosis in six cases. Nine out of 15 cases (60%) showed presence of acid-fast bacilli on Ziehl–Neelsen stain. Any evidence of pulmonary tuberculosis was ruled out by chest X-ray findings. The response to anti-tuberculosis therapy was desirable in all patients. Since the introduction of anti-tuberculous therapy, the incidence of LTB has declined. However, with the incidence of TB increasing, the overall incidence of laryngeal involvement may be on the rise. This study highlights the importance to consider the rare possibility of LTB in the presence of non-specific clinical and laryngoscopic signs and to confirm this by histological examination.

Microcystic Adenocarcinoma: An Initially Overlooked First Proposal of the Term

Challenges in Minor Salivary Gland Biopsies: A Practical Approach to Problematic Histologic Patterns Abstract Evaluation of minor salivary gland biopsy can be fraught with a wide range of problems, including technical limitations due to the small size and distorted nature of tissue received and interpretive difficulties navigating the considerable morphologic and immunohistochemical overlap between widely disparate entities. As such, common pathologic findings can evoke a perplexing differential diagnosis that encompasses malignant, benign, and non-neoplastic processes. This review will present the diagnostic considerations that arise from four histologic patterns that are frequently encountered on minor salivary gland biopsies: squamous differentiation, tubular and cribriform growth, mucin production, and myxoid stroma. The discussion herein will emphasize practical strategies and priorities for navigating these differential diagnoses in a clinically-relevant and cost-effective manner.

Acute Invasive Fungal Rhinosinusitis: Frozen Section Histomorphology and Diagnosis with PAS Stain Abstract Acute invasive fungal rhinosinusitis (AIFRS) is a fulminant infection in immunocompromised patients requiring rapid diagnosis (DX), frequently made on frozen section (FS) of sinonasal biopsies, followed by prompt surgical debridement. However, FS interpretation is often difficult and DX sometimes not possible. In this study we sought to characterize reasons for misinterpretation and methods to improve diagnostic accuracy. The FS slides from 271 biopsies of suspected AIFRS in a 16-year period were reviewed and the morphologic features evaluated for their utility in DX. Recurring specific patterns of necrosis were identified, which to our knowledge have not been described in the literature. Although they provide strong evidence for AIFRS, identifying fungus consistently in necrotic tissue is essential for DX. Clues to identifying fungus and pitfalls in misidentification were identified, but even with expert knowledge of these, a gap in accurate DX remained. The key to FS DX of AIFRS is to improve fungus identification in necrotic tissues. Methods had been sought in the past to stain fungus at FS without consistent success. The Periodic Acid Schiff’s Reaction for Fungi was modified by our histopathology department for use on frozen tissue (PASF-fs) resulting in effective staining of the fungus. It stained fungus on all 62 positive slides when applied retrospectively over hematoxylin and eosin (H&E) stained FSs and used prospectively at FS for DX. Although knowledge of histologic morphology on FS is important, the crucial value of this study is the novel use of PASF-fs to identify fungus in the DX of AIFRS.