Rare basal cell metastasis of a basal-squamous skin collision tumour to the lung and axillary lymph node

Abstract

We report a case of a 60-year-old man who was a former cigar smoker with a slow-growing, large exophytic left shoulder mass (15 cm in diameter) and later found to have left axillary lymphadenopathy. Fine needle aspirate biopsy of the left shoulder mass revealed squamous cell carcinoma (SCC). However, pathology of the enlarged left axillary lymph node was reported as metastatic adenocarcinoma. The patient underwent surgical resection of the shoulder mass which comprised of SCC (>95%) and adenoid basal cell carcinoma (BCC) as a second component of the tumour. The BCC had identical histology as the metastatic carcinoma in the left axillary lymph node. Therefore, diagnosis was revised as cutaneous collision tumour with metastatic BCC. Six months later following adjuvant radiation therapy, the patient was diagnosed with metastatic BCC in the right lung. Stereotactic body radiation therapy (SBRT) and a selective hedgehog pathway inhibitor vismodegib were given with only limited efficacy. Clinical trial registration number NCT03132636.

Collision tumors of the lung: A case report of urothelial carcinoma metastasizing to renal cell carcinoma with heterotopic ossification

“…The present case disclosed concurrent pulmonary metastases from kidney (RCC) and bladder (HGUC) cancers. The occurrence of metastatic non-pulmonary carcinoma with primary lung cancer at the same location in the lung has been reported [ 9 , 10 , 23 , 24 ]; however, simultaneous pulmonary metastases from kidney and bladder cancers are uncommon. A collision tumor refers to the coexistence of two or more tumors harboring different morphology, and clonal, and organ-specific origins within the same location but with none or minimal histological admixture [ 21 ].…”

“…They consist of at least two neoplastic cell populations, with different clonal ancestors and genetic background, colliding and expanding into each other. The term “collision tumor” goes back to the mid-1900s [ 4 , 5 ] when common sites of occurrence were described, including the stomach [ 6 , 7 ], lungs [ [8] , [9] , [10] ], liver [ 11 , 12 ], and adrenals [ 13 , 14 ] among others [ [15] , [16] , [17] , [18] ]. The mechanism by which collision tumors form is not fully understood; however, one of the following three theories might explain the pathogenesis and occurrence of this phenomenon: “random collision effect” [ [19] , [20] , [21] ], “field cancerization” [ 21 , 22 ], and “tumor-to-tumor carcinogenesis” [ 1 ].…”

“…The lung is one of the most common recipients of metastatic spreading; thus, several case reports describe collision tumors between either primary lung cancer and metastasizing tumor to the lung [ 9 , 10 , 23 , 24 ] or distinct primary lung cancers colliding together [ 17 , [25] , [26] , [27] , [28] ]. However, it is infrequent to have a collision tumor that consists of two different non-pulmonary tumors metastasizing to the lung.…”

<p>Multiple Skin Neoplasms at One Site (MUSK IN A NEST): A Comprehensive Review of Basal Cell Carcinoma and Benign or Malignant “Collision” Tumors at the Same Cutaneous Location</p>

“…Some of these tumors have unusual features. [73][74][75] A 71-year-old woman had a biopsy-confirmed squamous cell carcinoma in situ on her left palm; evaluation of the tumor debulking during Mohs micrographic surgery demonstrated not only the squamous cell carcinoma in situ in the epidermis but also BCC in the dermis. 73 A 93-yearold woman developed a mass on her right lower eyelid; an excisional biopsy showed a tumor, arising from the epidermis, composed of adjoining BCC and signet-ring squamous cell carcinoma.…”

“…74 And, a 60-year-old man presented with a 15 x 15 centimeter fungating left should mass that was a MUSK IN A NEST consisting of adenoid BCC and squamous cell carcinoma; he also had metastatic adenoid BCC to his left axillary lymph node and subsequently to his right lung. 75…”