Cytopathological Findings of Secretory Carcinoma of the Salivary Gland and the Diagnostic Utility of Giemsa Staining

Secretory carcinoma is a salivary gland neoplasm first described as a mammary analogue secretory carcinoma by Skalova et al. in 2010 and redesignated as a secretory carcinoma in the 2017 World Health Organization Classification of Head and Neck Tumors. Secretory carcinoma diagnosis is reliant on specific cytological and histological findings and the detection of an ETV6-NTRK3 fusion gene. Here, we examined the clinical and cytopathological features of four cases of secretory carcinoma occurring in three males and a female, aged between 39 and 74 years. All four tumors involved the parotid gland, and were found to have the ETV6-NTRK3 fusion gene. Fine-needle aspiration-based cytology smears of all tumors displayed papillary and/or dendritic pattern clusters, some of which were associated with blood vessels. The neoplastic cells displayed enlarged nuclei with fine chromatin and small, distinct, single nucleoli. Furthermore, several neoplastic cells with a characteristic vacuolated cytoplasm were identified in each specimen. Giemsa staining revealed cytoplasmic vacuolation, intracytoplasmic metachromatic secretions and/or various sized metachromatic granules, and a background of metachromatic mucin in all four specimens. Given this, we conclude that these cytological findings, especially those of the Giemsa staining, might be helpful in the diagnosis of secretory carcinoma.

Cutaneous mastocytosis in an infant: Case report and clinicopathological correlation

Mastocytosis is a disorder of clonal proliferation of the mast cells, which can be cutaneous or systemic. Abnormal mast cell infiltration comprising multifocal compact clusters or cohesive aggregates can affect one or more organ systems. Cutaneous mastocytosis is a relatively uncommon condition in the pediatric population. We report a case of 9 month infant presented with multiple papular and vesicular skin rashes since 6 months of age. On clinical examination Darier’s sign was negative. The serum tryptase levels were within normal limits. Clinical differential diagnoses were benign cephalic histiocytosis vs cutaneous mastocytosis. Skin biopsy revealed a mononuclear cell infiltrate in the papillary dermis reaching up to the dermo-epidermal junction. Toluidine blue staining highlighted the metachromatic granules. CD117, CD30 IHC stains were positive which confirmed the diagnosis of cutaneous mastocytosis. This case is presented to highlight the histomorphology and the special stains in cases of mastocytosis.

Multiple cutaneous mast cell tumours in a Boa imperator

Mast cell tumours (MCTs) are common in dogs and cats, but are only rarely reported in reptiles. This case documents the clinical and pathomorphological results from a Boa imperator with multiple cutaneous nodules, diagnosed as MCT based on histopathology, immunohistochemistry and electron microscopy approaches. Grossly, there were multifocal, poorly demarcated, mostly ulcerated nodules ~3 cm in diameter on the skin. Histologically, the dermis and the subcutaneous tissue were infiltrated by round cell populations with eosinophilic granules. Toluidine blue and Giemsa stain revealed metachromatic granules. Using immunohistochemistry, some cells exhibited cytoplasmic immunostaining positive for tryptase. Ultrastructurally, variable quantities of intracytoplasmic, spherical and electron-dense granules were also detected. The MCT literature on snakes is scarce, especially for the family Boidae, but MCTs should be considered a differential diagnosis for nodular skin lesions in reptiles.

Diffuse Cutaneous Mastocytosis (Pigmented Maculopapular Cutaneous Mastocytosis) in a Cat

Diffuse cutaneous mastocytosis was diagnosed in a 6-year-old, indoor, neutered female domestic European shorthair cat. Marked pruritus located mainly on the head and neck was noticed in the cat and in this area the animal had developed alopecia, crusts, and plaques. Histologically, monomorphic mast cells were found in the superficial dermis and around the hair follicles. Mast cells were well differentiated, with central nuclei and granular cytoplasm, with metachromatic granules which stained positively with Toluidine blue stain. The animal was successfully treated with oclacitinib at a dose of 1 mg/kg, twice a day per os.

Distribution of Mast Cells and Locations, Depths, and Sizes of the Putative Acupoints CV 8 and KI 16

The anatomical locations and sizes of acupuncture points (APs) are identified in traditional Chinese medicine by using the cun measurement method. More precise knowledge of those locations and sizes to submillimeter precision, along with their cytological characterizations, would provide significant contributions both to scientific investigations and to precise control of the practice of acupuncture. Over recent decades, researchers have come to realize that APs in the skin of rats and humans have more mast cells (MCs) than neighboring nonacupoints. In this work, the distribution of MCs in the ventral skin of mice was studied so that it could be used to infer the locations, depths from the epidermis, and sizes of three putative APs. The umbilicus was taken as the reference point, and a transversal cross section through it was studied. The harvested skins from 8-week-old mice were stained with toluidine blue, and the MCs were recognized by their red-purple stains and their metachromatic granules. The three putative APs, CV 8 and the left and the right KI 16 APs, were identified based on their high densities of MCs. These findings also imply that acupuncture may stimulate, through MCs, an immune response to allergic inflammation.

Multiple cutaneous mast cell tumors in a pig

Cutaneous tumors are not usually observed in pigs, and mast cell tumors, in particular, have been rarely described. The current report describes numerous, pink to red, elevated, 1–5-cm nodules in the skin of a 6-month-old slaughter pig. The histopathology of the nodules revealed well-demarcated, but poorly differentiated, populations of round cells that extended from the dermis into subcutaneous tissues. The presence of eosinophils and the observation, at high magnification, of cells with cytoplasmic metachromatic granules, after toluidine blue staining, confirmed the diagnosis of multiple cutaneous mast cell tumors.