Schwannoma of breast is a relatively uncommon disease characterized by painless and slow growing. We report a case of a 28-year-old female who present a mass of the right breast. Ultrasonography revealed a well-circumscribed and inhomogeneous hypoechoic mass under the skin of the breast. Then a biopsy and immunohistochemical analysis were performed. The results were suggestive for cellular schwannoma of breast. The tumour was removed successfully and the patient has been followed-up for six months with no evidence of recurrence. Cellular schwannoma is a rare benign neoplasm without metastasis. Distinction cellular schwannoma from other malignant tumours is very important. It is necessary to combine strict criteria on histological, immunohistochemical analysis, biological behavior, image examination and clinical features for the final diagnosis.

Paragangliomas of the head and neck are uncommon tumors arising from parasympathetic ganglia. Paragangliomas are mostly asymptomatic and may manifest as palpable mass of neck. The morphologic features are non-specific and comparable to the other neuroendocrine tumors. Most of hereditary cases are associated with alterations in genes of succinate dehydrogenase (SDH). SDHA and SDHB immunohistochemistry is considered as reliable screening method to detect tumors with genetical alterations. Of note, SDHB mutated paragangliomas have the highest risk of local recurrence, distant metastasis and the development of other tumor phenotypes, which are associated with mutation. Therefore, active surveillance of patients and early surgical treatment are essential. In contrast, SDHB mutated head and neck paragangliomas was considered as completely benign tumors, although, the latest literature describes more controversial cases, which may increase awareness. Here, we present a rare case of 21 years old female with asymptomatic neck paraganglioma, which was unexpectedly diagnosed after pathological and immunohistochemical testing of removed thyroid gland and showed unusual immunohistochemical variation for SDH mutation.

Angiolymphoid hyperplasia with eosinophilia (ALHE) is an uncommon benign vascular proliferation characterized by isolated or grouped red-brown papules or nodules, most often located on the head or neck. Treatment of ALHE is difficult, with high recurrence rates reported across a myriad of different interventions. We report an atypical clinical presentation of ALHE that was successfully treated with a novel dual-therapeutic approach consisting of surgical excision followed by treatment with the pulsed dye laser.

The phenomenon of heterotopic bone formation (osseous metaplasia) is defined as an abnormal ossification of non-skeletal tissues and does represent a rare occurrence in the renal cell carcinoma setting. We describe a case of a 40-year old man with bilateral renal cell carcinomas of the histological clear cell subtype, with the right-sided renal cell carcinoma demonstrating heterotopic bone formation, as well as the presence of intratumoral adipose tissue. The etiology of bone formation in a renal cell carcinoma is unclear, but possible explanations include a response to tissue ischemia and the expression of Bone Morphogenetic Protein 2. The detection of these rare morphologic variations is of paramount importance, not to be mistaken as sarcomatoid transformation and renal sinus fat invasion, which would advance the pathologic tumor stage and aggressiveness of the disease.