A 61-year-old Chinese male presented with a progressive painful swelling in the right parotid gland for one month prior to attending our hospital. The patient had a history of heavy smoking, but did not complain of hemoptysis or other symptoms related to lung cancer. A clinical examination showed the size of the mass to be approximately 1 × 1 cm, with a good activity and a moderate texture. An ultrasound showed there to be a hypoechoic nodule with a size of 1.3× 1.3 × 0.9 cm. Therefore our initial diagnosis was that of a primary parotid tumor and we recommended surgical treatment. However, in preoperative routine examinations, a chest X-ray (Figure ) showed there to be a high density shadow in the right hilar. At this stage we highly suspected that the mass was metastases and required further examination. A lung computational tomography (CT) scan (Figure ) revealed a shadow in the right upper lobe, with a size of approximately 5.4 × 6.3 cm. The CT value was 40HU, and the enhanced CT value was 60HU, with multiple lymph nodes in the mediastinum appearing enlarged. After consulting with the patient, we performed an operation constituting of a partial parotidectomy and facial nerve dissection. Postoperative pathology reported a small-cell lung cancer metastases to parotid (Figure ). Immunohistochemistry showed TTF(thyroid transcription factor)-1(+), Syn (Synaptophysin) (+), actin (-), S-100(-), P63 (-), EMA (epithelial membrane antigen) (-), ck(cytokeratin)20 (-). Therefore, we recommended that the patient receive postoperative radiation and chemotherapy.
A 19-year-old woman with pain and swelling in her right parotid gland was referred to Shohada Hospital (Tehran-Iran) with no underlying diseases. She has complained of a mobile mass on the parotid region for a duration of 3 months. In her clinical examination, the oral mucosa and overlying skin were observed as intact with normal color. The patient's magnetic resonance imaging (MRI) indicated a high signal of a lobular-contoured, as a 4 × 2.5 cm solid mass lesion in the superior lobe of her right parotid gland (Figure ). A fine needle aspiration biopsy was performed by a maxillofacial surgeon and then a pathologic report indicated an unknown type of soft tissue malignancy. The primary diagnosis and the surgical treatment plan were discussed for the patient and a written consent was then obtained from her. At the operation session, following conducting the frozen-sections evaluation, malignant spindle cell tumor was diagnosed. Thereafter, a total parotidectomy was performed. As well, the gross examination of the specimen revealed a solid creamy mass with an almost well-defined border, invading the superficial lobe of the parotid gland. In addition, the permanent microscopic sections demonstrated a malignant neoplasm composed of fascicles of atypical spindle-shaped cells with large pleomorphic vesicular nuclei, prominent nucleoli, and clear-to-pale eosinophilic cytoplasm arranged in a storiform pattern (Figure ). Multinucleated giant cells and lymphocytic infiltration were observed as well. Notably, mitotic activity was about 4/10 HPF. By performing an immunohistochemically analysis, it was found that the atypical cells were HMB45 (Figure ) and S100 positive (Figure ). However, other markers such as Myo D1, Desmin, PanCK, and CK5/6 were negative. The microscopic feature along with IHC findings was consistent with the result of melanoma diagnosis.\nTo discover the primary origin of the recent melanoma lesion, a comprehensive past medical history was taken from the study case. As a result, we found that she had a history of congenital scalp pigmented nevus with no pathological consultation or any report of metastasis after 2 years (Figure ). Considering the possibility that the scalp lesion may be the origin of metastatic malignant melanoma, we suggested her to undergo excisional biopsy of the newly developed scalp lesion. In this regard, the patient was referred to the dermatology department for both consultation and performing the excisional biopsy operation. Thereafter, the newly formed scalp lesion was surgically removed. As well, the gross examination of the specimen showed safe border margins (0.6–1 cm) as well as a pigmented lesion in the center. Sections also demonstrated skin tissue with dissipated pigments from the epidermis to deep dermis. Moreover, the proliferation of atypical spindle cells scattered in the stroma was arranged from the superficial epidermis to hypodermis with vesicular nuclei and eosinophilic nucleolus (Figure ). Of note, the mitotic activity was about 1 in 10 HPF. In this patient, immunohistochemical staining showed the HMB45 intense positivity, but Ki67 was estimated as lower than 5%. Therefore, according to all these findings, the diagnosis of malignant melanoma was confirmed. After a month, she underwent parotidectomy due to swelling and pain in the left parotid gland. The histopathological report showed the same malignant melanoma. Thereafter, adjuvant chemotherapy and radiotherapy were performed for her during 6 and 4 sessions, respectively. She followed her disease by administrating complementary medicines too (homeopathy). After 18 months of follow-up, the lesion has not recurred and she has still been on a regular follow-up program.