C79.82

Secondary malignant neoplasm of genital organs

C79.82 represents metastatic disease that has spread to the genital organs from a primary malignancy located elsewhere in the body. In female anatomy, this includes secondary neoplasms of the uterus (corpus or cervix), vagina, and vulva; notably, secondary malignant neoplasms of the ovary are coded separately under category C79.6. In male anatomy, this code encompasses metastases to the testes, penis, or scrotum. These secondary involvements are clinically significant as they typically indicate advanced-stage (Stage IV) systemic cancer. The most frequent primary sources for these metastases include the gastrointestinal tract (stomach or colon), breast, lung, and kidney. Diagnosis usually requires histopathological examination and immunohistochemistry to confirm the cellular origin and differentiate the metastatic deposit from a primary genital tract cancer. Management is generally palliative and guided by the treatment protocols for the primary tumor site.

Clinical Symptoms

  • Abnormal vaginal bleeding or spotting
  • Pelvic pain or pressure
  • Palpable pelvic or adnexal mass
  • Abnormal vaginal discharge
  • Dyspareunia (painful intercourse)
  • Scrotal swelling or palpable testicular mass
  • Penile lesions, nodules, or ulcerations
  • Hematuria if the metastatic lesion invades the urinary tract
  • Obstructive voiding symptoms
  • Unintentional weight loss
  • General malaise and fatigue
  • Priapism (rarely associated with penile metastasis)

Common Causes

  • Metastasis from primary gastrointestinal malignancies (e.g., colorectal or gastric cancer)
  • Metastatic spread from primary breast carcinoma
  • Dissemination from primary lung cancer
  • Hematogenous spread from primary renal cell carcinoma
  • Metastatic cutaneous melanoma
  • Lymphatic spread from regional or distant lymph nodes
  • Direct extension from adjacent pelvic organs such as the bladder or rectum
  • Transcoelomic seeding (peritoneal spread)

Documentation & Coding Tips

Identify and document the primary malignancy site to ensure proper sequencing and risk adjustment.

Example: Patient with secondary malignant neoplasm of the bilateral ovaries (C79.82) metastatic from primary invasive ductal carcinoma of the upper-outer quadrant of the left female breast (C50.412). Currently undergoing systemic chemotherapy. This documentation supports HCC 11 (Colorectal, Lung, and Other Cancers).

Billing Focus: Sequencing of codes where the primary site is documented alongside the secondary site.

Explicitly state the specific genital organ involved to avoid less specific coding options within the C79.82 category.

Example: Clinical evaluation reveals a secondary malignant neoplasm of the scrotum (C79.82), which represents a cutaneous metastasis from the patient's known primary adenocarcinoma of the rectosigmoid junction (C19). The presence of distant metastasis indicates Stage IV disease. Billing requires the specific C79.82 code in conjunction with the primary site.

Billing Focus: Site specificity within the genital tract (e.g., scrotum, vagina, or adnexa).

Document the presence of any associated complications such as malignant ascites or pleural effusion.

Example: Secondary malignant neoplasm of the uterus and ovaries (C79.82) with associated malignant ascites (R18.0) and hydronephrosis due to pelvic mass compression. Plan involves paracentesis and continuation of palliative oncology regimen. This documentation justifies higher E/M levels and additional procedure codes.

Billing Focus: Coding of associated symptoms or complications that are not inherent to the malignancy.

Clarify the treatment status, including whether the primary site has been resected or is currently being treated.

Example: Patient with personal history of primary colon cancer (Z85.038) now presenting with a new secondary malignant neoplasm of the vulva (C79.82). Biopsy confirms metastatic colon origin. Patient is scheduled for palliative radiation therapy. Billing must distinguish between active secondary cancer and the history of the primary site.

Billing Focus: Differentiates between active malignancy and personal history codes (Z85 series).

Incorporate pathology results that define the morphology of the secondary lesion, such as Krukenberg tumor.

Example: Pathology confirms a Krukenberg tumor of the ovaries, coded as a secondary malignant neoplasm of genital organs (C79.82) originating from a primary gastric adenocarcinoma (C16.9). The patient presents with pelvic pain and bloating. High MDM due to the need for multi-specialty coordination. Billing includes both the secondary and primary sites.

Billing Focus: Linking the secondary site to a specific morphological diagnosis provided by pathology.

Relevant CPT Codes